JP3533334B2 - Carbon dioxide sensor and method for measuring carbon dioxide concentration - Google Patents
Carbon dioxide sensor and method for measuring carbon dioxide concentrationInfo
- Publication number
- JP3533334B2 JP3533334B2 JP27260998A JP27260998A JP3533334B2 JP 3533334 B2 JP3533334 B2 JP 3533334B2 JP 27260998 A JP27260998 A JP 27260998A JP 27260998 A JP27260998 A JP 27260998A JP 3533334 B2 JP3533334 B2 JP 3533334B2
- Authority
- JP
- Japan
- Prior art keywords
- oxide
- carbon dioxide
- metal
- hydrogen carbonate
- dioxide sensor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 title claims description 320
- 239000001569 carbon dioxide Substances 0.000 title claims description 158
- 229910002092 carbon dioxide Inorganic materials 0.000 title claims description 158
- 238000000034 method Methods 0.000 title claims description 20
- 150000004706 metal oxides Chemical class 0.000 claims description 138
- 229910044991 metal oxide Inorganic materials 0.000 claims description 137
- 238000001514 detection method Methods 0.000 claims description 87
- 229910052751 metal Inorganic materials 0.000 claims description 83
- 239000002184 metal Substances 0.000 claims description 83
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims description 80
- 239000007784 solid electrolyte Substances 0.000 claims description 73
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 30
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 28
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 claims description 16
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 14
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 14
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 14
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 claims description 13
- 239000010416 ion conductor Substances 0.000 claims description 11
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 claims description 10
- 229910021645 metal ion Inorganic materials 0.000 claims description 10
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 claims description 9
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 claims description 9
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 claims description 8
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 8
- 239000000395 magnesium oxide Substances 0.000 claims description 8
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 8
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 claims description 8
- 229910003437 indium oxide Inorganic materials 0.000 claims description 7
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(iii) oxide Chemical group [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 claims description 7
- 229910000480 nickel oxide Inorganic materials 0.000 claims description 7
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 claims description 7
- 229910001887 tin oxide Inorganic materials 0.000 claims description 7
- 239000005751 Copper oxide Substances 0.000 claims description 6
- 229910000416 bismuth oxide Inorganic materials 0.000 claims description 6
- CXKCTMHTOKXKQT-UHFFFAOYSA-N cadmium oxide Inorganic materials [Cd]=O CXKCTMHTOKXKQT-UHFFFAOYSA-N 0.000 claims description 6
- CFEAAQFZALKQPA-UHFFFAOYSA-N cadmium(2+);oxygen(2-) Chemical compound [O-2].[Cd+2] CFEAAQFZALKQPA-UHFFFAOYSA-N 0.000 claims description 6
- VTYYLEPIZMXCLO-UHFFFAOYSA-L calcium carbonate Substances [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 6
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims description 6
- 229910000420 cerium oxide Inorganic materials 0.000 claims description 6
- 229910000431 copper oxide Inorganic materials 0.000 claims description 6
- TYIXMATWDRGMPF-UHFFFAOYSA-N dibismuth;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Bi+3].[Bi+3] TYIXMATWDRGMPF-UHFFFAOYSA-N 0.000 claims description 6
- 229910000464 lead oxide Inorganic materials 0.000 claims description 6
- 229910000032 lithium hydrogen carbonate Inorganic materials 0.000 claims description 6
- HQRPHMAXFVUBJX-UHFFFAOYSA-M lithium;hydrogen carbonate Chemical compound [Li+].OC([O-])=O HQRPHMAXFVUBJX-UHFFFAOYSA-M 0.000 claims description 6
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims description 6
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims description 6
- CWBWCLMMHLCMAM-UHFFFAOYSA-M rubidium(1+);hydroxide Chemical compound [OH-].[Rb+].[Rb+] CWBWCLMMHLCMAM-UHFFFAOYSA-M 0.000 claims description 6
- NDVLTYZPCACLMA-UHFFFAOYSA-N silver oxide Chemical compound [O-2].[Ag+].[Ag+] NDVLTYZPCACLMA-UHFFFAOYSA-N 0.000 claims description 6
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 claims description 6
- 239000011787 zinc oxide Substances 0.000 claims description 6
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 5
- 229910001942 caesium oxide Inorganic materials 0.000 claims description 5
- KOPBYBDAPCDYFK-UHFFFAOYSA-N caesium oxide Chemical compound [O-2].[Cs+].[Cs+] KOPBYBDAPCDYFK-UHFFFAOYSA-N 0.000 claims description 5
- 235000010216 calcium carbonate Nutrition 0.000 claims description 5
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 5
- 229910000428 cobalt oxide Inorganic materials 0.000 claims description 5
- IVMYJDGYRUAWML-UHFFFAOYSA-N cobalt(ii) oxide Chemical compound [Co]=O IVMYJDGYRUAWML-UHFFFAOYSA-N 0.000 claims description 5
- QGLKJKCYBOYXKC-UHFFFAOYSA-N nonaoxidotritungsten Chemical compound O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 QGLKJKCYBOYXKC-UHFFFAOYSA-N 0.000 claims description 5
- MMKQUGHLEMYQSG-UHFFFAOYSA-N oxygen(2-);praseodymium(3+) Chemical compound [O-2].[O-2].[O-2].[Pr+3].[Pr+3] MMKQUGHLEMYQSG-UHFFFAOYSA-N 0.000 claims description 5
- 235000015497 potassium bicarbonate Nutrition 0.000 claims description 5
- 229910000028 potassium bicarbonate Inorganic materials 0.000 claims description 5
- 239000011736 potassium bicarbonate Substances 0.000 claims description 5
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 claims description 5
- 229940086066 potassium hydrogencarbonate Drugs 0.000 claims description 5
- 229910003447 praseodymium oxide Inorganic materials 0.000 claims description 5
- 229910001948 sodium oxide Inorganic materials 0.000 claims description 5
- 229910001930 tungsten oxide Inorganic materials 0.000 claims description 5
- 229910000410 antimony oxide Inorganic materials 0.000 claims description 4
- ZMCUDHNSHCRDBT-UHFFFAOYSA-M caesium bicarbonate Chemical compound [Cs+].OC([O-])=O ZMCUDHNSHCRDBT-UHFFFAOYSA-M 0.000 claims description 4
- NKWPZUCBCARRDP-UHFFFAOYSA-L calcium bicarbonate Chemical compound [Ca+2].OC([O-])=O.OC([O-])=O NKWPZUCBCARRDP-UHFFFAOYSA-L 0.000 claims description 4
- 229910000020 calcium bicarbonate Inorganic materials 0.000 claims description 4
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 claims description 4
- 239000000292 calcium oxide Substances 0.000 claims description 4
- KEDRKJFXBSLXSI-UHFFFAOYSA-M hydron;rubidium(1+);carbonate Chemical compound [Rb+].OC([O-])=O KEDRKJFXBSLXSI-UHFFFAOYSA-M 0.000 claims description 4
- 229910001947 lithium oxide Inorganic materials 0.000 claims description 4
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 claims description 4
- QWDJLDTYWNBUKE-UHFFFAOYSA-L magnesium bicarbonate Chemical compound [Mg+2].OC([O-])=O.OC([O-])=O QWDJLDTYWNBUKE-UHFFFAOYSA-L 0.000 claims description 4
- 239000002370 magnesium bicarbonate Substances 0.000 claims description 4
- 229910000022 magnesium bicarbonate Inorganic materials 0.000 claims description 4
- 235000014824 magnesium bicarbonate Nutrition 0.000 claims description 4
- VTRUBDSFZJNXHI-UHFFFAOYSA-N oxoantimony Chemical compound [Sb]=O VTRUBDSFZJNXHI-UHFFFAOYSA-N 0.000 claims description 4
- 229910001950 potassium oxide Inorganic materials 0.000 claims description 4
- CHWRSCGUEQEHOH-UHFFFAOYSA-N potassium oxide Chemical compound [O-2].[K+].[K+] CHWRSCGUEQEHOH-UHFFFAOYSA-N 0.000 claims description 4
- 229910001952 rubidium oxide Inorganic materials 0.000 claims description 4
- SIWVEOZUMHYXCS-UHFFFAOYSA-N oxo(oxoyttriooxy)yttrium Chemical compound O=[Y]O[Y]=O SIWVEOZUMHYXCS-UHFFFAOYSA-N 0.000 claims description 3
- 229910001923 silver oxide Inorganic materials 0.000 claims description 3
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 claims 1
- 239000007789 gas Substances 0.000 description 35
- 239000000843 powder Substances 0.000 description 35
- 229910052727 yttrium Inorganic materials 0.000 description 35
- 229910052706 scandium Inorganic materials 0.000 description 32
- 230000004044 response Effects 0.000 description 28
- 239000010931 gold Substances 0.000 description 22
- 229910052761 rare earth metal Inorganic materials 0.000 description 17
- 239000007864 aqueous solution Substances 0.000 description 16
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 15
- 238000000926 separation method Methods 0.000 description 14
- 230000035945 sensitivity Effects 0.000 description 12
- 239000012298 atmosphere Substances 0.000 description 11
- 229910052745 lead Inorganic materials 0.000 description 11
- 238000005259 measurement Methods 0.000 description 11
- -1 oxygen ions Chemical class 0.000 description 11
- 239000011734 sodium Substances 0.000 description 11
- 239000002228 NASICON Substances 0.000 description 10
- 239000002245 particle Substances 0.000 description 10
- WUOACPNHFRMFPN-SECBINFHSA-N (S)-(-)-alpha-terpineol Chemical compound CC1=CC[C@@H](C(C)(C)O)CC1 WUOACPNHFRMFPN-SECBINFHSA-N 0.000 description 9
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 9
- OVKDFILSBMEKLT-UHFFFAOYSA-N alpha-Terpineol Natural products CC(=C)C1(O)CCC(C)=CC1 OVKDFILSBMEKLT-UHFFFAOYSA-N 0.000 description 9
- 229940088601 alpha-terpineol Drugs 0.000 description 9
- 239000011575 calcium Substances 0.000 description 9
- 239000008188 pellet Substances 0.000 description 8
- 230000004043 responsiveness Effects 0.000 description 8
- 238000010521 absorption reaction Methods 0.000 description 7
- 230000008859 change Effects 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 7
- HTUMBQDCCIXGCV-UHFFFAOYSA-N lead oxide Chemical compound [O-2].[Pb+2] HTUMBQDCCIXGCV-UHFFFAOYSA-N 0.000 description 7
- 150000002910 rare earth metals Chemical class 0.000 description 7
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 6
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- 238000010494 dissociation reaction Methods 0.000 description 6
- 230000005593 dissociations Effects 0.000 description 6
- 229910052716 thallium Inorganic materials 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical class OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 5
- 150000002500 ions Chemical class 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 239000011572 manganese Substances 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 5
- 229910052712 strontium Inorganic materials 0.000 description 5
- 229910052788 barium Inorganic materials 0.000 description 4
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000004949 mass spectrometry Methods 0.000 description 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 238000007650 screen-printing Methods 0.000 description 4
- 241000894007 species Species 0.000 description 4
- 229910000873 Beta-alumina solid electrolyte Inorganic materials 0.000 description 3
- 238000000862 absorption spectrum Methods 0.000 description 3
- 229910052787 antimony Inorganic materials 0.000 description 3
- 229910052797 bismuth Inorganic materials 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 235000011187 glycerol Nutrition 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000010948 rhodium Substances 0.000 description 3
- 229910052701 rubidium Inorganic materials 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 229910052596 spinel Inorganic materials 0.000 description 3
- 239000011029 spinel Substances 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- 229910018921 CoO 3 Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910003249 Na3Zr2Si2PO12 Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910006404 SnO 2 Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- GEZOTWYUIKXWOA-UHFFFAOYSA-L copper;carbonate Chemical compound [Cu+2].[O-]C([O-])=O GEZOTWYUIKXWOA-UHFFFAOYSA-L 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- XUCJHNOBJLKZNU-UHFFFAOYSA-M dilithium;hydroxide Chemical compound [Li+].[Li+].[OH-] XUCJHNOBJLKZNU-UHFFFAOYSA-M 0.000 description 2
- FZFYOUJTOSBFPQ-UHFFFAOYSA-M dipotassium;hydroxide Chemical compound [OH-].[K+].[K+] FZFYOUJTOSBFPQ-UHFFFAOYSA-M 0.000 description 2
- 239000007772 electrode material Substances 0.000 description 2
- 238000003905 indoor air pollution Methods 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- UFQXGXDIJMBKTC-UHFFFAOYSA-N oxostrontium Chemical compound [Sr]=O UFQXGXDIJMBKTC-UHFFFAOYSA-N 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 229910000027 potassium carbonate Inorganic materials 0.000 description 2
- 235000011181 potassium carbonates Nutrition 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000010532 solid phase synthesis reaction Methods 0.000 description 2
- 238000004544 sputter deposition Methods 0.000 description 2
- MFEVGQHCNVXMER-UHFFFAOYSA-L 1,3,2$l^{2}-dioxaplumbetan-4-one Chemical compound [Pb+2].[O-]C([O-])=O MFEVGQHCNVXMER-UHFFFAOYSA-L 0.000 description 1
- ZXSQEZNORDWBGZ-UHFFFAOYSA-N 1,3-dihydropyrrolo[2,3-b]pyridin-2-one Chemical compound C1=CN=C2NC(=O)CC2=C1 ZXSQEZNORDWBGZ-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N Acrylic acid Chemical compound OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910016063 BaPb Inorganic materials 0.000 description 1
- 229910016062 BaRuO Inorganic materials 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910018871 CoO 2 Inorganic materials 0.000 description 1
- 229910017569 La2(CO3)3 Inorganic materials 0.000 description 1
- 229910012465 LiTi Inorganic materials 0.000 description 1
- 229910012949 LiV2O4 Inorganic materials 0.000 description 1
- 229910017682 MgTi Inorganic materials 0.000 description 1
- 229910017493 Nd 2 O 3 Inorganic materials 0.000 description 1
- YZCKVEUIGOORGS-IGMARMGPSA-N Protium Chemical compound [1H] YZCKVEUIGOORGS-IGMARMGPSA-N 0.000 description 1
- 229910018540 Si C Inorganic materials 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- 229910003114 SrVO Inorganic materials 0.000 description 1
- 239000004809 Teflon Substances 0.000 description 1
- 229920006362 Teflon® Polymers 0.000 description 1
- FMRLDPWIRHBCCC-UHFFFAOYSA-L Zinc carbonate Chemical compound [Zn+2].[O-]C([O-])=O FMRLDPWIRHBCCC-UHFFFAOYSA-L 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910001413 alkali metal ion Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229940036348 bismuth carbonate Drugs 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 229910000011 cadmium carbonate Inorganic materials 0.000 description 1
- GKDXQAKPHKQZSC-UHFFFAOYSA-L cadmium(2+);carbonate Chemical compound [Cd+2].[O-]C([O-])=O GKDXQAKPHKQZSC-UHFFFAOYSA-L 0.000 description 1
- FJDQFPXHSGXQBY-UHFFFAOYSA-L caesium carbonate Chemical compound [Cs+].[Cs+].[O-]C([O-])=O FJDQFPXHSGXQBY-UHFFFAOYSA-L 0.000 description 1
- 229910000024 caesium carbonate Inorganic materials 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 150000005323 carbonate salts Chemical class 0.000 description 1
- GHLITDDQOMIBFS-UHFFFAOYSA-H cerium(3+);tricarbonate Chemical compound [Ce+3].[Ce+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O GHLITDDQOMIBFS-UHFFFAOYSA-H 0.000 description 1
- XHFVDZNDZCNTLT-UHFFFAOYSA-H chromium(3+);tricarbonate Chemical compound [Cr+3].[Cr+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O XHFVDZNDZCNTLT-UHFFFAOYSA-H 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 229910021446 cobalt carbonate Inorganic materials 0.000 description 1
- ZOTKGJBKKKVBJZ-UHFFFAOYSA-L cobalt(2+);carbonate Chemical compound [Co+2].[O-]C([O-])=O ZOTKGJBKKKVBJZ-UHFFFAOYSA-L 0.000 description 1
- UBEWDCMIDFGDOO-UHFFFAOYSA-N cobalt(2+);cobalt(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[Co+2].[Co+3].[Co+3] UBEWDCMIDFGDOO-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229940116318 copper carbonate Drugs 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- GMZOPRQQINFLPQ-UHFFFAOYSA-H dibismuth;tricarbonate Chemical compound [Bi+3].[Bi+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O GMZOPRQQINFLPQ-UHFFFAOYSA-H 0.000 description 1
- AKUNKIJLSDQFLS-UHFFFAOYSA-M dicesium;hydroxide Chemical compound [OH-].[Cs+].[Cs+] AKUNKIJLSDQFLS-UHFFFAOYSA-M 0.000 description 1
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- RAQDACVRFCEPDA-UHFFFAOYSA-L ferrous carbonate Chemical compound [Fe+2].[O-]C([O-])=O RAQDACVRFCEPDA-UHFFFAOYSA-L 0.000 description 1
- 239000010408 film Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000010413 gardening Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000003898 horticulture Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- BDAGIHXWWSANSR-NJFSPNSNSA-N hydroxyformaldehyde Chemical compound O[14CH]=O BDAGIHXWWSANSR-NJFSPNSNSA-N 0.000 description 1
- AMNSWIGOPDBSIE-UHFFFAOYSA-H indium(3+);tricarbonate Chemical compound [In+3].[In+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O AMNSWIGOPDBSIE-UHFFFAOYSA-H 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- NZPIUJUFIFZSPW-UHFFFAOYSA-H lanthanum carbonate Chemical compound [La+3].[La+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O NZPIUJUFIFZSPW-UHFFFAOYSA-H 0.000 description 1
- 229960001633 lanthanum carbonate Drugs 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000011656 manganese carbonate Substances 0.000 description 1
- 235000006748 manganese carbonate Nutrition 0.000 description 1
- 229940093474 manganese carbonate Drugs 0.000 description 1
- 229910000016 manganese(II) carbonate Inorganic materials 0.000 description 1
- XMWCXZJXESXBBY-UHFFFAOYSA-L manganese(ii) carbonate Chemical compound [Mn+2].[O-]C([O-])=O XMWCXZJXESXBBY-UHFFFAOYSA-L 0.000 description 1
- 230000007102 metabolic function Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- UTWHRPIUNFLOBE-UHFFFAOYSA-H neodymium(3+);tricarbonate Chemical compound [Nd+3].[Nd+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O UTWHRPIUNFLOBE-UHFFFAOYSA-H 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- ZULUUIKRFGGGTL-UHFFFAOYSA-L nickel(ii) carbonate Chemical compound [Ni+2].[O-]C([O-])=O ZULUUIKRFGGGTL-UHFFFAOYSA-L 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 238000009304 pastoral farming Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000008635 plant growth Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- XIRHLBQGEYXJKG-UHFFFAOYSA-H praseodymium(3+);tricarbonate Chemical compound [Pr+3].[Pr+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O XIRHLBQGEYXJKG-UHFFFAOYSA-H 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000001028 reflection method Methods 0.000 description 1
- 239000012744 reinforcing agent Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- IGLNJRXAVVLDKE-UHFFFAOYSA-N rubidium atom Chemical compound [Rb] IGLNJRXAVVLDKE-UHFFFAOYSA-N 0.000 description 1
- WPFGFHJALYCVMO-UHFFFAOYSA-L rubidium carbonate Chemical compound [Rb+].[Rb+].[O-]C([O-])=O WPFGFHJALYCVMO-UHFFFAOYSA-L 0.000 description 1
- 229910000026 rubidium carbonate Inorganic materials 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- LKZMBDSASOBTPN-UHFFFAOYSA-L silver carbonate Substances [Ag].[O-]C([O-])=O LKZMBDSASOBTPN-UHFFFAOYSA-L 0.000 description 1
- 229910001958 silver carbonate Inorganic materials 0.000 description 1
- VFWRGKJLLYDFBY-UHFFFAOYSA-N silver;hydrate Chemical compound O.[Ag].[Ag] VFWRGKJLLYDFBY-UHFFFAOYSA-N 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910000018 strontium carbonate Inorganic materials 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
- QVOIJBIQBYRBCF-UHFFFAOYSA-H yttrium(3+);tricarbonate Chemical compound [Y+3].[Y+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O QVOIJBIQBYRBCF-UHFFFAOYSA-H 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 239000011667 zinc carbonate Substances 0.000 description 1
- 235000004416 zinc carbonate Nutrition 0.000 description 1
- 229910000010 zinc carbonate Inorganic materials 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Landscapes
- Measuring Oxygen Concentration In Cells (AREA)
Description
【0001】[0001]
【発明の属する技術分野】本発明は、室内外の環境制
御、施設園芸等の農工業プロセス、防災、生体表面の代
謝機能の測定などに使用される二酸化炭素センサおよび
二酸化炭素濃度の測定方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon dioxide sensor used for indoor and outdoor environment control, agricultural and industrial processes such as horticulture, disaster prevention, and measurement of metabolic function on the surface of a living body, and a method for measuring carbon dioxide concentration. .
【0002】[0002]
【従来の技術】近年、空調の普及に伴う室内空気の汚染
の検知、畜産における施設内空気の汚染の検知、園芸施
設における植物の成長制御、各種工業プロセスなどを中
心に、二酸化炭素センサに対するニーズが高まってお
り、種々の方式の二酸化炭素センサが提案されている。2. Description of the Related Art In recent years, there has been a need for a carbon dioxide sensor centering on the detection of indoor air pollution accompanying the spread of air conditioning, the detection of indoor air pollution in livestock farming, plant growth control in gardening facilities, various industrial processes, etc. Is increasing, and various types of carbon dioxide sensors have been proposed.
【0003】具体的には、例えば、赤外線吸収方式の二
酸化炭素センサが実用化されている。しかし、この方式
のセンサは、装置が大きいこと、高価であることなどか
ら、普及するには至っていない。また、半導体を用いた
センサも提案されているが、このセンサは二酸化炭素の
選択性に劣るため、二酸化炭素のみの濃度を測定するこ
とが困難である。Specifically, for example, an infrared absorption type carbon dioxide sensor has been put into practical use. However, this type of sensor has not been widely used because of its large size and high cost. Although a sensor using a semiconductor has been proposed, it is difficult to measure the concentration of only carbon dioxide because this sensor has poor selectivity for carbon dioxide.
【0004】これに対して、小型で安価なセンサとし
て、固体電解質を用いたものがいくつか提案されてい
る。On the other hand, some sensors using a solid electrolyte have been proposed as small and inexpensive sensors.
【0005】丸山ら{第10回固体イオニクス討論会講
演要旨集69(1983)}は、二酸化炭素と解離平衡
を形成する炭酸カリウムなどの固体電解質に一対の電極
を形成し、一方に濃度既知の基準ガスを接触させて、雰
囲気ガスの濃度差による起電力を測定する濃淡分極型セ
ンサを提案している。また、丸山らは、このような濃淡
分極型センサの他、NASICON(ナトリウムスーパ
ーイオン伝導体:Na3Zr2Si2PO12)などのアル
カリ金属イオン伝導性の固体電解質に一対の電極を形成
し、一方に炭酸ナトリウムなどの二酸化炭素と解離平衡
を形成する金属炭酸塩層を設けて検知極とし、他方を二
酸化炭素不感応性電極とした、いわゆる起電力検出型セ
ンサも提案している。Maruyama et al. [Abstracts of Lectures at the 10th Solid Ionics Discussion Session 69 (1983)] form a pair of electrodes on a solid electrolyte such as potassium carbonate which forms a dissociation equilibrium with carbon dioxide, and one of them has a known concentration. We have proposed a density-polarization sensor that measures the electromotive force due to the difference in concentration of atmospheric gas by contacting a reference gas. Maruyama et al. Formed a pair of electrodes on an alkali metal ion conductive solid electrolyte such as NASICON (sodium super ionic conductor: Na 3 Zr 2 Si 2 PO 12 ) in addition to such a gray-scale polarization sensor. Also, a so-called electromotive force detection type sensor is proposed, in which one side is provided with a metal carbonate layer that forms a dissociation equilibrium with carbon dioxide such as sodium carbonate to serve as a detection electrode, and the other side is used as a carbon dioxide insensitive electrode.
【0006】特公平4−79542号公報では、二酸化
炭素と解離平衡を形成する金属塩の金属イオン導電性を
有する固体電解質に一対の電極を形成し、一方の電極を
上記金属塩で被覆し、もう一方の電極および残余の固体
電解質表面にガス遮断層で被覆している二酸化炭素セン
サが提案されている。In Japanese Patent Publication No. 4-79542, a pair of electrodes are formed on a solid electrolyte having metal ion conductivity of a metal salt that forms dissociation equilibrium with carbon dioxide, and one electrode is coated with the above metal salt. A carbon dioxide sensor has been proposed in which the other electrode and the remaining solid electrolyte surface are coated with a gas barrier layer.
【0007】特開平7−63726号公報では、アルカ
リイオン伝導体からなる固体電解質に、電子および酸素
イオンの伝導体である固体基準極を圧着させた固体基準
極型二酸化炭素センサが提案されている。Japanese Unexamined Patent Publication (Kokai) No. 7-63726 proposes a solid reference electrode type carbon dioxide sensor in which a solid reference electrode which is a conductor of electrons and oxygen ions is pressure bonded to a solid electrolyte made of an alkali ion conductor. .
【0008】固体電解質を用いた小型で安価な二酸化炭
素センサの問題点としては、まず材料として使用される
金属炭酸塩が湿度の影響を受けやすいことがある。この
問題を解決するためには、センサ素子のガス検知部以外
を密閉したり、センサをヒータにより加熱して作動温度
を高くして、湿度の影響を低減しなければならない。上
記のセンサの作動温度は400〜700℃と高温であ
る。作動温度が高いと、センサ全体の消費電力が大き
く、また、材料の熱劣化が起こる等の問題が生じてく
る。また、数百℃の熱は、たとえ小さなヒータからであ
ってもセンサ周辺を加温し、空気の対流を発生するな
ど、測定環境に微妙な影響を与えてしまうという問題も
ある。A problem with a small and inexpensive carbon dioxide sensor using a solid electrolyte is that the metal carbonate used as a material is susceptible to humidity. In order to solve this problem, it is necessary to hermetically seal the parts other than the gas detection part of the sensor element or heat the sensor with a heater to raise the operating temperature to reduce the influence of humidity. The operating temperature of the above sensor is as high as 400 to 700 ° C. When the operating temperature is high, power consumption of the entire sensor is large, and problems such as thermal deterioration of materials occur. There is also a problem that heat of several hundreds of degrees Celsius heats the periphery of the sensor even when using a small heater to generate convection of air, which has a delicate influence on the measurement environment.
【0009】さらに、金属炭酸塩が湿度の影響を受けや
すいため、センサの使用停止時には素子を乾燥雰囲気中
で保存する必要がある。さらには、使用時に、停止中に
素子に進入した水分の除去等のためにベーキングが必要
で、センサの出力電圧が安定するまでに長時間要し、作
業性やエネルギー的な問題が存在する。これらはセンサ
を高温で動作させる場合には、不可避な問題であり、よ
り低い温度で動作するセンサが求められている。Further, since the metal carbonate is susceptible to humidity, it is necessary to store the element in a dry atmosphere when the sensor is not used. Furthermore, during use, baking is required to remove moisture that has entered the element during stoppage, and it takes a long time for the output voltage of the sensor to stabilize, which causes workability and energy problems. These are unavoidable problems when the sensor is operated at a high temperature, and there is a demand for a sensor that operates at a lower temperature.
【0010】この問題に対して、S.Breikhinら{Applie
d PhysicsA 57, 37-43(1993)}は、固体電解質と半導体
とを接合させた二酸化炭素センサを報告している。この
二酸化炭素センサは、検知極としてSbやVをドープし
たSnO2半導体を用い、これに固体電解質としてナト
リウムイオン導電体であるNASICONを接合させ、
検知極の反対側に参照極としてNaxCoO2を配置して
いる。この二酸化炭素センサは低温(−35℃〜室温)
作動が可能であるが、応答が見られるまで4分以上かか
ってしまうという問題がある。また、耐湿性も悪く、相
対湿度(湿度)によって応答時間や感度が変化してしま
い、安定した性能を得ることが困難である。To address this issue, S. Breikhin et al. {Applie
d PhysicsA 57, 37-43 (1993)} reported a carbon dioxide sensor in which a solid electrolyte and a semiconductor were joined. This carbon dioxide sensor uses a SnO 2 semiconductor doped with Sb or V as a detection electrode, and a sodium ion conductor NASICON is bonded to this as a solid electrolyte,
Na x CoO 2 is arranged as a reference electrode on the opposite side of the detection electrode. This carbon dioxide sensor has a low temperature (-35 ° C to room temperature)
It is possible to operate, but there is a problem that it takes more than 4 minutes to see a response. Further, the humidity resistance is also poor, and the response time and the sensitivity change depending on the relative humidity (humidity), and it is difficult to obtain stable performance.
【0011】[0011]
【発明が解決しようとする課題】本発明の目的は、室温
で作動し、十分な感度と応答性が得られ、選択性が高
く、耐湿性にも優れた二酸化炭素センサと、この二酸化
炭素センサを用いた二酸化炭素濃度の測定方法とを提供
することである。It is an object of the present invention to operate at room temperature, obtain sufficient sensitivity and responsiveness, have high selectivity and excellent moisture resistance, and this carbon dioxide sensor. And a method for measuring a carbon dioxide concentration using the method.
【0012】[0012]
【課題を解決するための手段】このような目的は、下記
の本発明により達成される。The above object is achieved by the present invention described below.
【0013】(1) 検知極と対極とがそれぞれ固体電
解質に接して設けられており、前記固体電解質が金属イ
オン導電体を含有し、前記検知極が、金属酸化物を含有
する金属酸化物層と、集電体とを有し、前記検知極が、
少なくとも二酸化炭素存在下で、炭酸水素イオンを含有
する二酸化炭素センサ。
(2) 検知極と対極とがそれぞれ固体電解質に接して
設けられており、前記固体電解質が金属イオン導電体を
含有し、前記検知極が、金属酸化物を含有する金属酸化
物層と、集電体とを有し、前記金属酸化物層が金属炭酸
水素塩を含有する二酸化炭素センサ。
(3) 前記金属酸化物層が金属炭酸水素塩および/ま
たは金属炭酸塩を含有する上記(1)または(2)の二
酸化炭素センサ。
(4) 前記金属酸化物層が、炭酸水素リチウム、炭酸
水素ナトリウム、炭酸水素カリウム、炭酸水素ルビジウ
ム、炭酸水素セシウム、炭酸水素マグネシウムおよび炭
酸水素カルシウムのいずれか一種以上を含有する上記
(2)または(3)の二酸化炭素センサ。
(5) 前記金属酸化物層が、金属炭酸水素塩および/
または金属炭酸塩を前記金属酸化物に対して1〜99wt
%含有する上記(2)〜(4)のいずれかの二酸化炭素
センサ。
(6) 前記金属酸化物層が、酸化インジウム、酸化ス
ズ、酸化コバルト、酸化タングステン、酸化亜鉛、酸化
鉛、酸化銅、酸化鉄、酸化ニッケル、酸化クロム、酸化
カドミウム、酸化ビスマス、酸化マンガン、酸化イット
リウム、酸化アンチモン、酸化ランタン、酸化セリウ
ム、酸化プラセオジム、酸化ネオジム、酸化銀、酸化リ
チウム、酸化ナトリウム、酸化カリウム、酸化ルビジウ
ム、酸化セシウム、酸化マグネシウム、酸化カルシウ
ム、酸化ストロンチウムおよび酸化バリウムのいずれか
一種以上を含有する上記(1)〜(5)のいずれかの二
酸化炭素センサ。
(7) 前記金属酸化物層が多孔質である上記(1)〜
(6)のいずれかの二酸化炭素センサ。
(8) 前記炭酸水素イオンが前記金属酸化物層表面に
存在する上記(1)、(3)、(4)、(5)、(6)
または(7)のいずれかの二酸化炭素センサ。
(9) 前記炭酸水素イオンが前記固体電解質表面に存
在する上記(1)、(3)、(4)、(5)、(6)ま
たは(7)のいずれかの二酸化炭素センサ。
(10) 前記固体電解質の可動イオン種が前記金属酸
化物層に侵入している上記(1)〜(9)のいずれかの
二酸化炭素センサ。
(11) 前記集電体が多孔質金属である上記(1)〜
(10)のいずれかの二酸化炭素センサ。
(12) 前記集電体が前記金属酸化物層を挟んで固体
電解質に対向して設けられている上記(1)〜(11)
のいずれかの二酸化炭素センサ。
(13) 前記検知極と前記対極とが前記固体電解質の
同一の面上に設けられている上記(1)〜(12)のい
ずれかの二酸化炭素センサ。
(14) 前記対極が金属または金属酸化物のいずれか
一種以上を含有する上記(1)〜(13)のいずれかの
二酸化炭素センサ。
(15) 上記(1)〜(14)のいずれかの二酸化炭
素センサを用い、二酸化炭素が炭酸水素イオンの形で前
記検知極に吸着して二酸化炭素濃度が測定される二酸化
炭素濃度の測定方法。
(16) 前記炭酸水素イオンが前記金属酸化物表面に
吸着する上記(15)の二酸化炭素濃度の測定方法。
(17) 前記炭酸水素イオンが前記固体電解質表面に
吸着する上記(15)の二酸化炭素濃度の測定方法。(1) A sensing electrode and a counter electrode are respectively provided in contact with a solid electrolyte, the solid electrolyte contains a metal ion conductor, and the sensing electrode contains a metal oxide layer containing a metal oxide. And a current collector, the detection electrode,
A carbon dioxide sensor containing hydrogen carbonate ions in the presence of at least carbon dioxide. (2) A detection electrode and a counter electrode are respectively provided in contact with a solid electrolyte, the solid electrolyte contains a metal ion conductor, and the detection electrode contains a metal oxide layer containing a metal oxide and a metal oxide layer. A carbon dioxide sensor having an electric body, wherein the metal oxide layer contains a metal hydrogen carbonate. (3) The carbon dioxide sensor according to (1) or (2) above, wherein the metal oxide layer contains a metal hydrogen carbonate and / or a metal carbonate. (4) The above (2), wherein the metal oxide layer contains one or more of lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, magnesium hydrogen carbonate and calcium hydrogen carbonate. The carbon dioxide sensor of (3). (5) The metal oxide layer comprises a metal hydrogen carbonate and /
Or 1 to 99 wt% of metal carbonate with respect to the metal oxide
% The carbon dioxide sensor according to any one of (2) to (4) above. (6) The metal oxide layer includes indium oxide, tin oxide, cobalt oxide, tungsten oxide, zinc oxide, lead oxide, copper oxide, iron oxide, nickel oxide, chromium oxide, cadmium oxide, bismuth oxide, manganese oxide, and oxidation. Any one of yttrium, antimony oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, silver oxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, magnesium oxide, calcium oxide, strontium oxide and barium oxide The carbon dioxide sensor according to any one of (1) to (5) above, containing the above. (7) The above (1) to (1) in which the metal oxide layer is porous.
The carbon dioxide sensor according to any one of (6). (8) The above-mentioned (1), (3), (4), (5), (6) in which the hydrogen carbonate ions are present on the surface of the metal oxide layer.
Alternatively, the carbon dioxide sensor according to any one of (7). (9) The carbon dioxide sensor according to any one of (1), (3), (4), (5), (6) or (7), wherein the hydrogen carbonate ions are present on the surface of the solid electrolyte. (10) The carbon dioxide sensor according to any one of (1) to (9) above, wherein mobile ionic species of the solid electrolyte penetrate into the metal oxide layer. (11) The above (1) to (1) in which the current collector is a porous metal.
The carbon dioxide sensor according to any one of (10). (12) The above (1) to (11), wherein the current collector is provided so as to face the solid electrolyte with the metal oxide layer interposed therebetween.
Carbon dioxide sensor of either. (13) The carbon dioxide sensor according to any one of (1) to (12), wherein the detection electrode and the counter electrode are provided on the same surface of the solid electrolyte. (14) The carbon dioxide sensor according to any of (1) to (13) above, wherein the counter electrode contains one or more kinds of a metal and a metal oxide. (15) A method of measuring a carbon dioxide concentration, wherein the carbon dioxide sensor according to any one of the above (1) to (14) is used to measure the carbon dioxide concentration by adsorbing carbon dioxide in the form of hydrogen carbonate ions on the detection electrode. . (16) The method for measuring the carbon dioxide concentration according to (15) above, wherein the hydrogen carbonate ions are adsorbed on the surface of the metal oxide. (17) The method for measuring a carbon dioxide concentration according to (15) above, wherein the hydrogen carbonate ions are adsorbed on the surface of the solid electrolyte.
【0014】[0014]
【作用】本発明の二酸化炭素センサは、検知極と対極と
がそれぞれ、金属イオン導電体を含有する固体電解質に
接して設けられており、検知極が、金属酸化物を含有す
る金属酸化物層と、集電体とを有する。検知極が接する
固体電解質の表面に、金属酸化物層を有することが好ま
しい。そして、この検知極は、少なくとも二酸化炭素存
在下で、炭酸水素イオンを含有する。検知極は、二酸化
炭素存在下において炭酸水素イオンを形成すればよい
が、予め炭酸水素イオンを含有している方が応答性がよ
く、好ましい。In the carbon dioxide sensor of the present invention, the detection electrode and the counter electrode are respectively provided in contact with the solid electrolyte containing the metal ion conductor, and the detection electrode is the metal oxide layer containing the metal oxide. And a current collector. It is preferable to have a metal oxide layer on the surface of the solid electrolyte in contact with the detection electrode. Then, this detection electrode contains hydrogen carbonate ions in the presence of at least carbon dioxide. The detection electrode may form hydrogencarbonate ions in the presence of carbon dioxide, but it is preferable to contain hydrogencarbonate ions in advance because the response is good.
【0015】検知極の金属酸化物層が金属酸化物、好ま
しくは酸化インジウム、酸化スズ、酸化コバルト、酸化
タングステン、酸化亜鉛、酸化鉛、酸化銅、酸化鉄、酸
化ニッケル、酸化クロム、酸化カドミウム、酸化ビスマ
ス、酸化マンガン、酸化イットリウム、酸化アンチモ
ン、酸化ランタン、酸化セリウム、酸化プラセオジム、
酸化ネオジム、酸化銀、酸化リチウム、酸化ナトリウ
ム、酸化カリウム、酸化ルビジウム、酸化セシウム、酸
化マグネシウム、酸化カルシウム、酸化ストロンチウム
および酸化バリウムのいずれか一種以上を含有し、さら
に、炭酸水素イオンを含有することにより、応答性が著
しく向上し、低温での迅速な測定が可能になる。これ
は、検出する二酸化炭素に由来する炭酸水素イオンが固
体電解質表面および/または金属酸化物表面に形成され
やすくなるからであると考えられる。予め検知極に炭酸
水素イオンが含有されていると、より二酸化炭素由来の
炭酸水素イオンが形成されやすくなる。本発明の二酸化
炭素センサは、炭酸ガスの分圧の変化に応じて炭酸水素
イオンの解離平衡が生じ、それによって二酸化炭素濃度
を測定するものである。本発明の二酸化炭素センサは、
室温で作動しても、応答速度が速く、高感度であり、二
酸化炭素選択性も高い。The metal oxide layer of the detection electrode is a metal oxide, preferably indium oxide, tin oxide, cobalt oxide, tungsten oxide, zinc oxide, lead oxide, copper oxide, iron oxide, nickel oxide, chromium oxide, cadmium oxide, Bismuth oxide, manganese oxide, yttrium oxide, antimony oxide, lanthanum oxide, cerium oxide, praseodymium oxide,
Contain at least one of neodymium oxide, silver oxide, lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, magnesium oxide, calcium oxide, strontium oxide and barium oxide, and further contain hydrogen carbonate ion This significantly improves responsiveness and enables quick measurement at low temperature. It is considered that this is because bicarbonate ions derived from carbon dioxide to be detected are easily formed on the solid electrolyte surface and / or the metal oxide surface. When the detection electrode contains hydrogen carbonate ions in advance, hydrogen carbonate ions derived from carbon dioxide are more likely to be formed. The carbon dioxide sensor of the present invention measures the carbon dioxide concentration by causing dissociation equilibrium of hydrogen carbonate ions in response to changes in the partial pressure of carbon dioxide. The carbon dioxide sensor of the present invention is
Even if it operates at room temperature, it has a fast response speed, high sensitivity, and high carbon dioxide selectivity.
【0016】炭酸水素イオンは、通常、固体電解質表面
および/または金属酸化物表面に結合して存在する。よ
り具体的には、固体電解質表面および/または金属酸化
物表面の−OH基と直接またはH2Oを介して結合して
存在する。固体電解質表面に存在する炭酸水素イオン、
導電性金属酸化物表面に存在する炭酸水素イオンとも
に、二酸化炭素濃度の測定に関与すると考えられる。炭
酸水素イオンが金属酸化物表面に形成される場合、金属
酸化物が電子伝導性に優れる場合は金属酸化物が導電体
として作用し、イオン伝導性に優れる場合は固体電解質
中の可動イオン種が金属酸化物層中に侵入することによ
り、起電力が発生する。The hydrogen carbonate ions are usually present in association with the solid electrolyte surface and / or the metal oxide surface. More specifically, it exists by being bonded to the —OH group on the surface of the solid electrolyte and / or the surface of the metal oxide directly or through H 2 O. Bicarbonate ions present on the surface of the solid electrolyte,
It is considered that both hydrogen carbonate ions existing on the surface of the conductive metal oxide are involved in the measurement of carbon dioxide concentration. When hydrogencarbonate ions are formed on the surface of the metal oxide, the metal oxide acts as a conductor when the metal oxide has excellent electronic conductivity, and when the metal oxide has excellent ionic conductivity, mobile ion species in the solid electrolyte are An electromotive force is generated by penetrating into the metal oxide layer.
【0017】さらに、金属酸化物層に金属炭酸水素塩お
よび/または金属炭酸塩、好ましくは金属炭酸水素塩を
含有させることにより、固体電解質表面および/または
金属酸化物表面への二酸化炭素由来の炭酸水素イオンの
生成がより促進され、感度、応答速度、選択性などの応
答性がさらに向上する。Further, by incorporating a metal hydrogen carbonate and / or a metal carbonate, preferably a metal hydrogen carbonate into the metal oxide layer, carbon dioxide derived from carbon dioxide on the surface of the solid electrolyte and / or the surface of the metal oxide. Generation of hydrogen ions is further promoted, and responsiveness such as sensitivity, response speed, and selectivity is further improved.
【0018】また、金属酸化物層に金属炭酸塩を含有さ
せることにより、よりペーストにしやすくなり、検知極
を形成しやすくなるため、検知極の固体電解質に対する
密着性がよくなり、応答速度が向上する。しかも、検知
極の形成時にスクリーン印刷等の作業が容易になるた
め、生産性が向上する。さらには、電極の強度も強くな
る。Further, by containing a metal carbonate in the metal oxide layer, it becomes easier to form a paste and a detection electrode is easily formed, so that the adhesion of the detection electrode to the solid electrolyte is improved and the response speed is improved. To do. Moreover, work such as screen printing is facilitated at the time of forming the detection electrode, so that productivity is improved. Furthermore, the strength of the electrode also increases.
【0019】また、集電体を多孔質としたり、集電体を
金属酸化物層を挟んで固体電解質に対向して設けること
により、検知極自体がガス拡散層として働くために、さ
らに迅速な応答が得られるようになる。Further, since the current collector is made porous or the current collector is provided so as to face the solid electrolyte with the metal oxide layer sandwiched therebetween, the sensing electrode itself functions as a gas diffusion layer, so that it is more rapid. You will get a response.
【0020】さらには、対極に金属酸化物を用いること
により、共存ガスの影響が軽減し、高い二酸化炭素選択
性が得られる。また、耐湿性が向上し、特に低温での測
定時の湿度の影響が軽減する。Furthermore, by using a metal oxide for the counter electrode, the influence of coexisting gas is reduced and a high carbon dioxide selectivity can be obtained. In addition, the moisture resistance is improved, and the influence of humidity is reduced especially when measuring at low temperatures.
【0021】本発明のセンサの作動温度は、検知極と対
極との組み合わせにより、今までの固体電解質を用いた
二酸化炭素センサよりも低温で作動させることができ、
熱による測定環境の変化が小さく、消費電力の低減が可
能となる。The operating temperature of the sensor of the present invention can be operated at a lower temperature than that of the conventional carbon dioxide sensor using the solid electrolyte by combining the detection electrode and the counter electrode.
Changes in the measurement environment due to heat are small, and power consumption can be reduced.
【0022】[0022]
【発明の実施の形態】本発明の二酸化炭素センサは、検
知極と対極とがそれぞれ固体電解質に接して設けられて
おり、前記固体電解質が金属イオン導電体を含有し、前
記検知極が、金属酸化物を含有する金属酸化物層と、集
電体とを有し、前記検知極が、さらに、炭酸水素イオン
を含有する。BEST MODE FOR CARRYING OUT THE INVENTION In the carbon dioxide sensor of the present invention, a detection electrode and a counter electrode are respectively provided in contact with a solid electrolyte, the solid electrolyte contains a metal ion conductor, and the detection electrode is a metal. It has a metal oxide layer containing an oxide and a current collector, and the detection electrode further contains hydrogen carbonate ions.
【0023】<固体電解質>本発明の二酸化炭素センサ
では、固体電解質に金属イオン導電体を用いる。金属イ
オン導電体としては、例えば、Na−β″アルミナ、N
a−βアルミナ、Na3Zr2PSi2O12、Na3Zr2
Si2PO12(NASICON)、Na−βGa2O3、
Na−Fe2O3、Na3Zr2PSi2P2O12、Li−β
アルミナ、Li14Zn(CeO4)、Li5AlO4、L
i1.4Ti1.6In0.4P3O12、K−βアルミナ、K1.6
Al0.8Ti7.2O16、K2MgTi7O16、CaS等が挙
げられる。中でも、NASICONが好ましい。これら
は化学量論組成から多少偏倚していてもよい。<Solid Electrolyte> In the carbon dioxide sensor of the present invention, a metal ion conductor is used as the solid electrolyte. Examples of the metal ion conductor include Na-β ″ alumina and N
a-β alumina, Na 3 Zr 2 PSi 2 O 12 , Na 3 Zr 2
Si 2 PO 12 (NASICON), Na-βGa 2 O 3 ,
Na-Fe 2 O 3, Na 3 Zr 2 PSi 2 P 2 O 12, Li-β
Alumina, Li 14 Zn (CeO 4 ), Li 5 AlO 4 , L
i 1.4 Ti 1.6 In 0.4 P 3 O 12 , K-β alumina, K 1.6
Al 0.8 Ti 7.2 O 16 , K 2 MgTi 7 O 16 , CaS and the like can be mentioned. Of these, NASICON is preferable. These may be slightly deviated from the stoichiometric composition.
【0024】固体電解質の作製法としては、通常用いら
れている固相法、ゾルゲル法、共沈法等のいずれでもよ
く、好ましくは固相法が用いられる。The solid electrolyte may be prepared by any of the commonly used solid phase method, sol-gel method, coprecipitation method, etc., preferably the solid phase method.
【0025】固体電解質には、金属イオン導電体以外
に、イオン導電性を妨げない程度の補強剤として、酸化
アルミニウム(Al2O3)、酸化ケイ素(SiO2)、
酸化ジルコニウム(ZrO2)、炭化ケイ素(Si
C)、窒化ケイ素(Si3N4)、酸化鉄(Fe2O3)等
が50wt%以下含有されていてもよい。これらは化学量
論組成から多少偏倚していてもよい。In addition to metal ion conductors, solid electrolytes include aluminum oxide (Al 2 O 3 ), silicon oxide (SiO 2 ), as reinforcing agents that do not interfere with ionic conductivity.
Zirconium oxide (ZrO 2 ), silicon carbide (Si
C), silicon nitride (Si 3 N 4 ), iron oxide (Fe 2 O 3 ) and the like may be contained in an amount of 50 wt% or less. These may be slightly deviated from the stoichiometric composition.
【0026】<検知極>
本発明の二酸化炭素センサでは、検知極は、金属酸化物
を含有する金属酸化物層と、集電体とから成る。検知極
は、さらに、通常、固体電解質表面および/または金属
酸化物表面に炭酸水素イオン(HCO3 -)を有する。検
知極に金属酸化物と炭酸水素イオンとを含有することに
より、低温での迅速な測定が可能になる。<Detection Electrode> In the carbon dioxide sensor of the present invention, the detection electrode comprises a metal oxide layer containing a metal oxide and a current collector. The sensing electrode also typically has bicarbonate ions (HCO 3 − ) on the solid electrolyte surface and / or the metal oxide surface. By containing the metal oxide and the hydrogen carbonate ion in the detection electrode, rapid measurement at low temperature becomes possible.
【0027】<検知極の金属酸化物層>
金属酸化物層は、酸化インジウム(In2O3)、酸化ス
ズ(SnO2)、酸化コバルト(Co3O4)、酸化タン
グステン(WO3)、酸化亜鉛(ZnO)、酸化鉛(P
bO)、酸化銅(CuO)、酸化鉄(Fe2O3、Fe
O)、酸化ニッケル(NiO)、酸化クロム(Cr
2O3)、酸化カドミウム(CdO)、酸化ビスマス(B
i2O3)、酸化マンガン(MnO2、Mn2O3)、酸化
イットリウム(Y2O3)、酸化アンチモン(Sb
2O3)、酸化ランタン(La2O3)、酸化セリウム(C
eO2)、酸化プラセオジム(Pr6O11)、酸化ネオジ
ム(Nd2O3)、酸化銀(Ag2O)、酸化リチウム
(Li2O)、酸化ナトリウム(Na2O)、酸化カリウ
ム(K2O)、酸化ルビジウム(Rb2O)、酸化セシウ
ム(Cs2O)、酸化マグネシウム(MgO)、酸化カ
ルシウム(CaO)、酸化ストロンチウム(SrO)お
よび酸化バリウム(BaO)のいずれか一種以上を含有
することが好ましい。これらは化学量論組成から多少偏
倚していてもよい。金属酸化物層の金属酸化物は、電子
伝導性に優れるか、イオン伝導性に優れるものが好まし
い。<Metal Oxide Layer of Detecting Electrode> The metal oxide layer includes indium oxide (In 2 O 3 ), tin oxide (SnO 2 ), cobalt oxide (Co 3 O 4 ), tungsten oxide (WO 3 ), Zinc oxide (ZnO), lead oxide (P
bO), copper oxide (CuO), iron oxide (Fe 2 O 3 , Fe
O), nickel oxide (NiO), chromium oxide (Cr
2 O 3 ), cadmium oxide (CdO), bismuth oxide (B
i 2 O 3 ), manganese oxide (MnO 2 , Mn 2 O 3 ), yttrium oxide (Y 2 O 3 ), antimony oxide (Sb)
2 O 3 ), lanthanum oxide (La 2 O 3 ), cerium oxide (C
eO 2 ), praseodymium oxide (Pr 6 O 11 ), neodymium oxide (Nd 2 O 3 ), silver oxide (Ag 2 O), lithium oxide (Li 2 O), sodium oxide (Na 2 O), potassium oxide (K 2 O), rubidium oxide (Rb 2 O), cesium oxide (Cs 2 O), magnesium oxide (MgO), calcium oxide (CaO), strontium oxide (SrO), and barium oxide (BaO). Preferably. These may be slightly deviated from the stoichiometric composition. The metal oxide of the metal oxide layer is preferably one having excellent electron conductivity or ionic conductivity.
【0028】金属酸化物としては、他に、以下のような
NaCl型酸化物、スピネル型酸化物、ペロブスカイト型酸
化物、層状ペロブスカイト型酸化物、パイロクロア型酸
化物、その他の酸化物も用いることができる。なお、こ
れらも化学量論組成から多少偏倚していてもよい。Other metal oxides are as follows.
A NaCl type oxide, a spinel type oxide, a perovskite type oxide, a layered perovskite type oxide, a pyrochlore type oxide, and other oxides can also be used. Incidentally, these may be slightly deviated from the stoichiometric composition.
【0029】NaCl型酸化物:TiO,VO,Nb
O,RO1-x( ここで、R:一種類以上の希土類(Sc
およびYを含む)、0≦x <1),LiVO2 等。NaCl type oxides: TiO, VO, Nb
O, RO 1-x (where R: one or more rare earth elements (Sc
And Y), 0 ≦ x <1), LiVO 2, etc.
【0030】スピネル型酸化物:LiTi2O4 ,Li
MxTi2-xO4 (ここで、M=Li,Al,Cr,0<
x<2),Li1-xMxTi2O4 (ここで、M=Mg,
Mn,0<x<1),LiV2O4 ,Fe3O4 等。Spinel type oxide: LiTi 2 O 4 , Li
M x Ti 2-x O 4 (where M = Li, Al, Cr, 0 <
x <2), Li 1-x M x Ti 2 O 4 (where M = Mg,
Mn, 0 <x <1), LiV 2 O 4 , Fe 3 O 4, etc.
【0031】ペロブスカイト型酸化物:ReO3 ,WO
3 ,MxReO3 (ここで、M金属,0<x<0.
5),MxWO3 (ここで、M=金属,0<x<0.
5),A2P8W32O112 (ここで、A=K,Rb,T
l),NaxTayW1-yO3 (ここで、0≦x<1,0
<y<1),RNbO3 (ここで、R:一種類以上の希
土類(ScおよびYを含む)),Na1-xSrxNbO3
(ここで、0≦x≦1),RTiO3 (ここで、R:一
種類以上の希土類(ScおよびYを含む)),Can+1
TinO3n+1-y (ここで、n=2,3,...,y>
0),CaVO3,SrVO3,R1-xSrxVO3 (ここ
で、R:一種類以上の希土類(ScおよびYを含む)、
0≦x≦1),R1-xBaxVO3 (ここで、R:一種類
以上の希土類(ScおよびYを含む)、0≦x≦1),
Srn+1VnO3n+1-y (ここで、n=1,2,
3....,y>0),Ban+1VnO3n+1-y (ここ
で、n=1,2,3....,y>0),R4BaCu5
O13-y (ここで、R:一種類以上の希土類(Scおよ
びYを含む)、0≦y),R5SrCu6O15(ここで、
R:一種類以上の希土類(ScおよびYを含む)),R
2SrCu2O6.2(ここで、R:一種類以上の希土類
(ScおよびYを含む)),R1-xSrxVO3 (ここ
で、R:一種類以上の希土類(ScおよびYを含
む)),CaCrO3,SrCrO3,RMnO3(ここ
で、R:一種類以上の希土類(ScおよびYを含
む)),R1-xSrxMnO3 (ここで、R:一種類以上
の希土類(ScおよびYを含む),0≦x≦1),R
1-xBaxMnO3 (ここで、R:一種類以上の希土類
(ScおよびYを含む),0≦x≦1),Ca1-xRxM
nO3-y (ここで、R:一種類以上の希土類(Scおよ
びYを含む),0≦x≦1,0≦y),CaFeO3 ,
SrFeO3,BaFeO3 ,SrCoO3 ,BaCo
O3 ,RCoO3 (ここで、R:一種類以上の希土類
(ScおよびYを含む)),R1-xSrxCoO3 (ここ
で、R:一種類以上の希土類(ScおよびYを含む),
0≦x≦1),R1−xBaxCoO3 (ここで、R:一
種類以上の希土類(ScおよびYを含む),0≦x≦
1),RNiO3 (ここで、R:一種類以上の希土類
(ScおよびYを含む)),RCuO3 (ここで、R:
一種類以上の希土類(ScおよびYを含む)),RNb
O3 (ここで、R:一種類以上の希土類(ScおよびY
を含む)),Nb12O29,CaRuO3 ,Ca1-xRxR
u1-yMnyO3 (ここで、R:一種類以上の希土類(S
cおよびYを含む),0≦x≦1,0≦y≦1),Sr
RuO3,Ca1-xMgxRuO3 (ここで、0≦x≦
1),Ca1-xSrxRuO3(ここで、0<x<1),
BaRuO3 ,Ca1-xBaxRuO3 (ここで、0<x
<1),(Ba,Sr)RuO3 ,Ba1-xKxRuO3
(ここで、0<x≦1),(R,Na)RuO3 (ここ
で、R:一種類以上の希土類(ScおよびYを含
む)),(R,M)RhO3 (ここで、R:一種類以上
の希土類(ScおよびYを含む),M=Ca,Sr,B
a),SrIrO3,BaPbO3 ,(Ba,Sr)P
bO3-y( ここで、0≦y<1),BaPb1-xBixO
3 (ここで、0<x≦1),Ba1-xKxBiO3 (ここ
で、0<x≦1),Sr(Pb,Sb)O3-y (ここ
で、0≦y<1),Sr(Pb,Bi)O3-y (ここ
で、0≦y<1),Ba(Pb,Sb)O3-y (ここ
で、0≦y<1), Ba(Pb,Bi)O3-y(ここ
で、0≦y<1),MMoO3 (ここで、M=Ca,S
r,Ba),(Ba,Ca,Sr)TiO3-x (ここ
で、0≦x)等。Perovskite type oxide: ReO 3 , WO
3 , MxReO 3 (where M metal, 0 <x <0.
5), MxWO 3 (where M = metal, 0 <x <0.
5), A 2 P 8 W 32 O 112 (where A = K, Rb, T
l), Na x Ta y W 1-y O 3 (where 0 ≦ x <1,0
<Y <1), RNbO 3 (where R is one or more kinds of rare earth elements (including Sc and Y)), Na 1-x Sr x NbO 3
(Where 0 ≦ x ≦ 1), RTiO 3 (where R: one or more kinds of rare earths (including Sc and Y)), C an + 1
Ti n O 3n + 1-y ( where, n = 2,3, ..., y >
0), CaVO 3 , SrVO 3 , R 1-x Sr x VO 3 (where R: one or more rare earth elements (including Sc and Y),
0 ≦ x ≦ 1), R 1-x Ba x VO 3 (where R: one or more kinds of rare earths (including Sc and Y), 0 ≦ x ≦ 1),
Sr n + 1 V n O 3n + 1-y (where n = 1, 2,
3. . . . , Y> 0), Ba n + 1 V n O 3n + 1-y (where n = 1, 2, 3, ..., y> 0), R 4 BaCu 5
O 13-y (where R: one or more kinds of rare earths (including Sc and Y), 0 ≦ y), R 5 SrCu 6 O 15 (where:
R: one or more kinds of rare earths (including Sc and Y)), R
2 SrCu 2 O 6 . 2 (here, R: one or more kinds of rare earths (including Sc and Y)), R 1-x Sr x VO 3 (here, R: one or more kinds of rare earths (including Sc and Y)), CaCrO 3 , SrCrO 3 , RMnO 3 (where R: one or more kinds of rare earths (including Sc and Y)), R 1-x Sr x MnO 3 (where R: one or more kinds of rare earths (Sc and Y). , 0 ≦ x ≦ 1), R
1-x Ba x MnO 3 (where R: one or more kinds of rare earths (including Sc and Y), 0 ≦ x ≦ 1), Ca 1-x R x M
nO 3-y (here, R: one or more kinds of rare earth elements (including Sc and Y), 0 ≦ x ≦ 1, 0 ≦ y), CaFeO 3 ,
SrFeO 3 , BaFeO 3 , SrCoO 3 , BaCo
O 3 , RCoO 3 (here, R: one or more kinds of rare earths (including Sc and Y)), R 1-x Sr x CoO 3 (here, R: one or more kinds of rare earths (including Sc and Y) ),
0 ≦ x ≦ 1), R 1 −x Ba x CoO 3 (where R: one or more kinds of rare earths (including Sc and Y), 0 ≦ x ≦
1), RNiO 3 (where R: one or more rare earth elements (including Sc and Y)), RCuO 3 (where R:
One or more rare earth elements (including Sc and Y)), RNb
O 3 (where R: one or more rare earth elements (Sc and Y
)), Nb 12 O 29 , CaRuO 3 , Ca 1-x R x R
u 1-y Mn y O 3 ( wherein, R: one or more rare earth (S
(including c and Y), 0 ≦ x ≦ 1, 0 ≦ y ≦ 1), Sr
RuO 3 , Ca 1-x Mg x RuO 3 (where 0 ≦ x ≦
1), Ca 1-x Sr x RuO 3 (where 0 <x <1),
BaRuO 3 , Ca 1-x Ba x RuO 3 (where 0 <x
<1), (Ba, Sr) RuO 3 , Ba 1-x K x RuO 3
(Where 0 <x ≦ 1), (R, Na) RuO 3 (where R: one or more rare earth elements (including Sc and Y)), (R, M) RhO 3 (where R : One or more kinds of rare earths (including Sc and Y), M = Ca, Sr, B
a), SrIrO 3 , BaPbO 3 , (Ba, Sr) P
bO 3-y (where 0 ≦ y <1), BaPb 1-x Bi x O
3 (where 0 <x ≦ 1), Ba 1-x K x BiO 3 (where 0 <x ≦ 1), Sr (Pb, Sb) O 3-y (where 0 ≦ y <1) ), Sr (Pb, Bi) O 3-y (where 0 ≦ y <1), Ba (Pb, Sb) O 3-y (where 0 ≦ y <1), Ba (Pb, Bi) O 3-y (where 0 ≦ y <1), MMoO 3 (where M = Ca, S
r, Ba), (Ba, Ca, Sr) TiO 3−x (where 0 ≦ x) and the like.
【0032】層状ペロブスカイト型酸化物(K2NiF4
型を含む):Rn+1NinO3n+1 (ここで、R:Ba,
Sr,希土類(ScおよびYを含む)のうち一種類以
上,n=1〜5の整数),Rn+1CunO3n+1 (ここ
で、R:Ba,Sr,希土類(ScおよびYを含む)の
うち一種類以上,n=1〜5の整数),Sr2RuO
4 ,Sr2RhO4 ,Ba2RuO4 ,Ba2RhO4
等。Layered perovskite oxide (K 2 NiF 4
(Including mold): R n + 1 N in O 3n + 1 (where R: Ba,
One or more of Sr and rare earth (including Sc and Y), n = 1 to 5 integer, R n + 1 Cu n O 3n + 1 (where R: Ba, Sr, rare earth (Sc and Y) (Including an integer), n = 1 to an integer of 5), Sr 2 RuO
4 , Sr 2 RhO 4 , Ba 2 RuO 4 , Ba 2 RhO 4
etc.
【0033】パイロクロア型酸化物:R2V2O7-y(こ
こで、R:一種類以上の希土類(ScおよびYを含
む),0≦y<1),Tl2Mn2O7-y (ここで、0≦
y<1),R2Mo2O7-y (ここで、R:一種類以上の
希土類(ScおよびYを含む),0≦y<1),R2R
u2O7-y (ここで、R:Tl,Pb,Bi,希土類
(ScおよびYを含む)のうち一種類以上,0≦y<
1),Bi2-xPbxPt2-x RuxO7-y (ここで、0
≦x≦2,0≦y<1),Pb2(Ru,Pb)O7-y
(ここで、0≦y<1),R2Rh2O7-y (ここで、
R:Tl,Pb,Bi,Cd,希土類(ScおよびYを
含む)のうち一種類以上,0≦y<1),R2Pd2O7-
y (ここで、R:Tl,Pb,Bi,Cd,希土類(S
cおよびYを含む)のうち一種類以上,0≦y<1),
R2Re2O7-y (ここで、R:Tl,Pb,Bi,C
d,希土類(ScおよびYを含む)のうち一種類以上,
0≦y<1),R2Os2O7−y (ここで、R:Tl,
Pb,Bi,Cd,希土類(ScおよびYを含む)のう
ち一種類以上,0≦y<1),R2Ir2O7-y (ここ
で、R:Tl,Pb,Bi,Cd,希土類(Scおよび
Yを含む)のうち一種類以上,0≦y<1),R2Pt2
R>O7-y (ここで、R:Tl,Pb,Bi,Cd,希土
類(ScおよびYを含む)のうち一種類以上,0≦y<
1)等。Pyrochlore type oxide: R 2 V 2 O 7-y (where R: one or more kinds of rare earths (including Sc and Y), 0 ≦ y <1), Tl 2 Mn 2 O 7-y (Where 0 ≦
y <1), R 2 Mo 2 O 7-y (where R: one or more kinds of rare earth elements (including Sc and Y), 0 ≦ y <1), R 2 R
u 2 O 7-y (wherein one or more of R: Tl, Pb, Bi, rare earth (including Sc and Y), 0 ≦ y <
1), Bi 2-x Pb x Pt 2-x Ru x O 7-y (where 0
≦ x ≦ 2, 0 ≦ y <1), Pb 2 (Ru, Pb) O 7-y
(Where 0 ≦ y <1), R 2 Rh 2 O 7-y (where
R: one or more of Tl, Pb, Bi, Cd, rare earth (including Sc and Y), 0 ≦ y <1), R 2 Pd 2 O 7-
y (where R: Tl, Pb, Bi, Cd, rare earth (S
(including c and Y), 0 ≦ y <1),
R 2 Re 2 O 7-y (where R: Tl, Pb, Bi, C
d, one or more of rare earths (including Sc and Y),
0 ≦ y <1), R 2 Os 2 O 7 − y (where R: Tl,
One or more of Pb, Bi, Cd, rare earths (including Sc and Y), 0 ≦ y <1), R 2 Ir 2 O 7-y (where R: Tl, Pb, Bi, Cd, rare earths One or more types (including Sc and Y), 0 ≦ y <1), R 2 Pt 2
R> O 7-y (wherein R: Tl, Pb, Bi, Cd, one or more kinds of rare earth (including Sc and Y), 0 ≦ y <
1) etc.
【0034】その他の酸化物:R4Re6O19 (ここ
で、R:一種類以上の希土類(ScおよびYを含
む)),R4Ru6O19 (ここで、R:一種類以上の希
土類(ScおよびYを含む)),Bi3Ru3O11 ,V2
O3 ,Ti2O3 ,Rh2O3 ,VO2,CrO2 ,Nb
O2 ,MoO2 ,WO2 ,ReO2 ,RuO2 ,RhO
2 ,OsO2 ,IrO2 ,PtO2 ,PdO2 ,V3O5
,VnO2n-1 (n=4から9の整数),SnO2-x
(ここで、0≦x<1),La2Mo2O7, ,(M,M
o)O(ここで、M=Na,K,Rb,Tl),Mon
O3n-1 (n=4,8,9,10),Mo17O47 ,Pd
1-xLixO(ここで、x≦0.1)等。Inを含む酸化
物。Other oxides: R 4 Re 6 O 19 (where R is one or more kinds of rare earth elements (including Sc and Y)), R 4 Ru 6 O 19 (where R is one or more kinds). Rare earths (including Sc and Y)), Bi 3 Ru 3 O 11 , V 2
O 3 , Ti 2 O 3 , Rh 2 O 3 , VO 2 , CrO 2 , Nb
O 2 , MoO 2 , WO 2 , ReO 2 , RuO 2 , RhO
2 , OsO 2 , IrO 2 , PtO 2 , PdO 2 , V 3 O 5
, V n O 2n-1 (n = an integer from 4 to 9), SnO 2-x
(Where 0 ≦ x <1), La 2 Mo 2 O 7 , (M, M
o) O (wherein, M = Na, K, Rb , Tl), Mo n
O 3n-1 (n = 4, 8, 9, 10), Mo 17 O 47 , Pd
1-x Li x O (where x ≦ 0.1) and the like. An oxide containing In.
【0035】金属酸化物は、1種を用いても、2種以上
を併用してもよい。The metal oxides may be used alone or in combination of two or more.
【0036】金属酸化物としては、これらの中でも、酸
化インジウム、酸化スズ、酸化コバルト、酸化タングス
テン、酸化亜鉛、酸化鉛、酸化銅、酸化鉄、酸化ニッケ
ル、酸化クロム、酸化カドミウム、酸化ビスマスが好ま
しく、特に、酸化インジウム、酸化スズ、酸化銅、酸化
亜鉛が好ましい。酸化リチウム、酸化ナトリウム、酸化
カリウム、酸化ルビジウム、酸化セシウム、酸化マグネ
シウム、酸化カルシウム、酸化ストロンチウム、酸化バ
リウムを用いると応答がよくなるが、湿度の影響を受け
やすいので、他の金属酸化物と組み合わせて用いること
が好ましい。Among them, indium oxide, tin oxide, cobalt oxide, tungsten oxide, zinc oxide, lead oxide, copper oxide, iron oxide, nickel oxide, chromium oxide, cadmium oxide and bismuth oxide are preferable as the metal oxide. In particular, indium oxide, tin oxide, copper oxide and zinc oxide are preferable. Lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide gives better response, but it is easily affected by humidity, so in combination with other metal oxides It is preferable to use.
【0037】また、金属酸化物層は、金属酸化物の他
に、金属炭酸水素塩および/または金属炭酸塩を含有す
ることが好ましい。これによって、二酸化炭素の検出に
必須の炭酸水素イオンの生成がさらに促進され、感度、
応答速度、選択性などの応答性が向上する。The metal oxide layer preferably contains a metal hydrogen carbonate and / or a metal carbonate in addition to the metal oxide. This further promotes the production of bicarbonate, which is essential for detecting carbon dioxide, and sensitivity,
Responsiveness such as response speed and selectivity is improved.
【0038】金属酸化物層は、金属炭酸塩よりも金属炭
酸水素塩を含有する方が、応答速度、感度ともによいの
で、好ましい。金属炭酸塩は、二酸化炭素、水分と反応
して金属炭酸水素塩となり、二酸化炭素に由来する炭酸
水素イオンの生成を促進すると考えられる。It is preferable that the metal oxide layer contains a metal hydrogen carbonate rather than a metal carbonate because both the response speed and the sensitivity are better. It is considered that the metal carbonate reacts with carbon dioxide and water to become a metal hydrogen carbonate, and promotes the generation of hydrogen carbonate ions derived from carbon dioxide.
【0039】金属炭酸水素塩としては、例えば、炭酸水
素リチウム(LiHCO3)、炭酸水素ナトリウム(N
aHCO3)、炭酸水素カリウム(KHCO3)、炭酸水
素ルビジウム(RbHCO3)、炭酸水素セシウム(C
sHCO3)、炭酸水素マグネシウム(Mg(HCO3)
2)、炭酸水素カルシウム(Ca(HCO3)2)等が挙
げられる。これらは1種を用いても2種以上を併用して
もかまわない。中でも、炭酸水素リチウム、炭酸水素ナ
トリウム、炭酸水素カリウム、特に炭酸水素ナトリウム
を用いることが好ましい。Examples of the metal hydrogen carbonate include lithium hydrogen carbonate (LiHCO 3 ) and sodium hydrogen carbonate (N
aHCO 3 ), potassium hydrogen carbonate (KHCO 3 ), rubidium hydrogen carbonate (RbHCO 3 ), cesium hydrogen carbonate (C
sHCO 3 ), magnesium hydrogen carbonate (Mg (HCO 3 )
2 ), calcium hydrogen carbonate (Ca (HCO 3 ) 2 ) and the like. These may be used alone or in combination of two or more. Of these, lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and particularly sodium hydrogen carbonate are preferably used.
【0040】また、金属炭酸塩としては、例えば、炭酸
リチウム(Li2CO3)、炭酸ナトリウム(Na2C
O3)、炭酸カリウム(K2CO3)、炭酸ルビジウム
(Rb2CO3)、炭酸セシウム(Cs2CO3)、炭酸マ
グネシウム(MgCO3)、炭酸カルシウム(CaC
O3)、炭酸ストロンチウム(SrCO3)、炭酸バリウ
ム(BaCO3)、炭酸マンガン(Mn(CO3)2、M
n2(CO3)3)、炭酸鉄(Fe2(CO3)3、FeCO
3)、炭酸ニッケル(NiCO3)、炭酸銅(CuC
O3)、炭酸コバルト(Co2(CO3)3)、炭酸クロム
(Cr2(CO3)3)、炭酸亜鉛(ZnCO3)、炭酸銀
(Ag2CO3)、炭酸カドミウム(CdCO3)、炭酸
インジウム(In2(CO3)3)、炭酸イットリウム
(Y2(CO3)3)、炭酸鉛(PbCO3)、炭酸ビスマ
ス(Bi2(CO3)3)、炭酸ランタン(La2(C
O3)3)、炭酸セリウム(Ce(CO3)3)、炭酸プラ
セオジム(Pr6(CO3)11)、炭酸ネオジム(Nd2
(CO3)3)等が挙げられる。金属炭酸塩は1種を用い
ても2種以上を併用してもよい。中でも、炭酸リチウ
ム、炭酸ナトリウム、炭酸カリウムを用いることが好ま
しい。また、金属炭酸水素塩と併用する場合、用いる金
属炭酸水素塩と同じ金属の炭酸塩を用いることが好まし
い。Examples of metal carbonates include lithium carbonate (Li 2 CO 3 ) and sodium carbonate (Na 2 C).
O 3), potassium carbonate (K 2 CO 3), rubidium carbonate (Rb 2 CO 3), cesium carbonate (Cs 2 CO 3), magnesium carbonate (MgCO 3), calcium carbonate (CaC
O 3 ), strontium carbonate (SrCO 3 ), barium carbonate (BaCO 3 ), manganese carbonate (Mn (CO 3 ) 2 , M
n 2 (CO 3 ) 3 ), iron carbonate (Fe 2 (CO 3 ) 3 , FeCO
3 ), nickel carbonate (NiCO 3 ), copper carbonate (CuC)
O 3), cobalt carbonate (Co 2 (CO 3) 3 ), chromium carbonate (Cr 2 (CO 3) 3 ), zinc carbonate (ZnCO 3), silver carbonate (Ag 2 CO 3), cadmium carbonate (CdCO 3) , Indium carbonate (In 2 (CO 3 ) 3 ), yttrium carbonate (Y 2 (CO 3 ) 3 ), lead carbonate (PbCO 3 ), bismuth carbonate (Bi 2 (CO 3 ) 3 ), lanthanum carbonate (La 2 ( C
O 3) 3), cerium carbonate (Ce (CO 3) 3) , praseodymium carbonate (Pr 6 (CO 3) 11 ), carbonate neodymium (Nd 2
(CO 3 ) 3 ) and the like. The metal carbonates may be used alone or in combination of two or more. Above all, it is preferable to use lithium carbonate, sodium carbonate, and potassium carbonate. When used in combination with a metal hydrogen carbonate, it is preferable to use a carbonate of the same metal as the metal hydrogen carbonate used.
【0041】特に、固体電解質の可動イオン種と同じ金
属の炭酸水素塩、炭酸塩を用いることが好ましい。In particular, it is preferable to use hydrogen carbonate or carbonate of the same metal as the mobile ion species of the solid electrolyte.
【0042】金属炭酸水素塩および/または金属炭酸塩
は、金属酸化物に対して1〜99wt%、特に5〜50wt
%加えることが好ましい。金属炭酸水素塩および/また
は金属炭酸塩を2種以上を併用する場合でも、添加量の
合計は上記の範囲であることが好ましい。The metal hydrogen carbonate and / or the metal carbonate is contained in an amount of 1 to 99 wt%, particularly 5 to 50 wt% based on the metal oxide.
% Is preferably added. Even when two or more metal hydrogen carbonates and / or metal carbonates are used in combination, the total addition amount is preferably within the above range.
【0043】金属酸化物、金属炭酸水素塩および金属炭
酸塩を2種以上用いる場合、それらを混合して用いても
よいし、用いる金属酸化物、金属炭酸水素塩、炭酸塩の
融点、または分解点以下の温度で熱処理し、複合化させ
て用いてもよい。When two or more kinds of metal oxides, metal hydrogen carbonates and metal carbonates are used, they may be mixed and used, or the metal oxides, metal hydrogen carbonates, melting points or decomposition of the metal oxides used. You may heat-process at the temperature below a point and you may make it compound and use.
【0044】検知極の金属酸化物層の形成方法は特に限
定されないが、通常、金属酸化物粉末、金属炭酸水素塩
粉末および金属炭酸塩粉末のペーストを固体電解質に塗
布し、用いる金属酸化物、炭酸水素塩、炭酸塩の融点、
または分解点以下の温度で2時間程度加熱処理して乾燥
させて形成することが好ましい。炭酸水素リチウムを用
いる場合は、分解しないように注意する。用いる金属酸
化物、金属炭酸水素塩、金属炭酸塩の平均粒径は10nm
〜100μm が好ましい。ペーストの溶媒としては、金
属酸化物、金属炭酸水素塩および金属炭酸塩が溶解した
り、反応したりしない有機溶媒で、室温蒸気圧が比較的
低く、作業性がよいものであればよい。特に、α−テル
ピネオール、エチレングリコール、グリセリン等が好ま
しい。スラリーの粘度は0.1〜100,000poise
が好ましい。The method of forming the metal oxide layer of the detection electrode is not particularly limited, but usually, a metal oxide powder, a metal hydrogencarbonate powder and a paste of the metal carbonate powder are applied to a solid electrolyte to be used, Bicarbonate, melting point of carbonate,
Alternatively, it is preferably formed by heating at a temperature below the decomposition point for about 2 hours and drying. When using lithium hydrogen carbonate, be careful not to decompose it. The average particle size of the metal oxide, metal hydrogen carbonate, and metal carbonate used is 10 nm.
˜100 μm is preferred. The solvent of the paste may be an organic solvent which does not dissolve or react with the metal oxide, the metal hydrogen carbonate and the metal carbonate, and has a relatively low room temperature vapor pressure and good workability. In particular, α-terpineol, ethylene glycol, glycerin and the like are preferable. The viscosity of the slurry is 0.1-100,000 poise
Is preferred.
【0045】また、検知極に金属炭酸水素塩および/ま
たは金属炭酸塩を含有させるには、金属酸化物のペース
トを固体電解質に塗布し、乾燥した後で、その上から金
属炭酸水素塩および/または金属炭酸塩の水溶液を塗布
し、金属酸化物層に含浸させることが好ましい。特に、
金属炭酸水素塩は熱分解しやすいので、水溶液を金属酸
化物層形成後に金属酸化物層に含浸させることが好まし
い。このようにすることで容易に金属炭酸水素塩および
/または金属炭酸塩を含有する金属酸化物層が形成でき
る。また、金属炭酸水素塩および/または金属炭酸塩の
水溶液を塗布した後で乾燥させる際に、あまり熱をかけ
なくてよいので好ましい。水溶液の濃度は0.1wt%以
上であることが好ましい。濃度の上限は特になく、飽和
水溶液まで好ましく用いることができる。ペーストを用
いると、ほとんどが炭酸水素塩、炭酸塩として存在し、
水溶液を用いると、炭酸水素イオンと炭酸水素塩、また
は、炭酸イオンと炭酸塩が存在する。このようにして検
知極に炭酸水素イオンが含有されることになるが、この
他、さらに、金属酸化物層に、炭酸水素イオンを含む水
溶液、例えば、炭酸水溶液や炭酸水素水溶液を検知極に
塗布したり、検知極を二酸化炭素を含む、好ましくは高
湿雰囲気に曝すことにより、炭酸水素イオンが検知極に
含有されることになる。In order to contain the metal hydrogen carbonate and / or the metal carbonate in the detection electrode, the metal oxide paste is applied to the solid electrolyte and dried, and then the metal hydrogen carbonate and / or Alternatively, it is preferable to apply an aqueous solution of a metal carbonate to impregnate the metal oxide layer. In particular,
Since the metal hydrogen carbonate is easily thermally decomposed, it is preferable to impregnate the metal oxide layer with the aqueous solution after forming the metal oxide layer. By doing so, the metal hydrogen carbonate and / or the metal oxide layer containing the metal carbonate can be easily formed. Further, it is preferable that the metal hydrogen carbonate and / or the metal carbonate aqueous solution is applied and then dried, since it does not require too much heat. The concentration of the aqueous solution is preferably 0.1 wt% or more. There is no particular upper limit to the concentration, and a saturated aqueous solution can be preferably used. When using the paste, most of it exists as hydrogen carbonate and carbonate,
When an aqueous solution is used, hydrogen carbonate ion and hydrogen carbonate salt or carbonate ion and carbonate salt are present. In this way, the detection electrode contains hydrogen carbonate ions. In addition to this, an aqueous solution containing hydrogen carbonate ions, for example, an aqueous solution of carbonic acid or an aqueous solution of hydrogen carbonate is applied to the detection electrode. Alternatively, by exposing the detection electrode to an atmosphere containing carbon dioxide, preferably a high humidity atmosphere, hydrogen carbonate ions are contained in the detection electrode.
【0046】また、金属酸化物層は薄膜プロセスにより
多孔質に形成させてもよい。金属酸化物層は多孔質であ
ることが好ましく、細孔径は0.01〜100μm が好
ましい。The metal oxide layer may be made porous by a thin film process. The metal oxide layer is preferably porous, and the pore size is preferably 0.01 to 100 μm.
【0047】<二酸化炭素濃度の測定方法>本発明のセ
ンサは、二酸化炭素存在下では、二酸化炭素と水分とに
由来する炭酸水素イオン(HCO3 -)が固体電解質表面
および/または金属酸化物表面に形成されると考えられ
る。そして、この炭酸水素イオンの解離平衡を電解質の
可動イオンの活量に変換して、二酸化炭素濃度の変化を
起電力として検出する。固体電解質にNASICONを
用いた場合、HCO3 -が固体電解質表面、金属酸化物表
面どちらに形成されても、電解質中の可動イオンである
Na+が、HCO3 -に引き寄せられ、検知極近傍に移動
する。また、イオン伝導性に優れる金属酸化物表面にH
CO3 -が形成されると、電解質中の可動イオンであるN
a+が金属酸化物層中に侵入する。このとき、NaHC
O3が生成する場合もある。<Method of Measuring Carbon Dioxide Concentration> In the sensor of the present invention, in the presence of carbon dioxide, hydrogen carbonate ions (HCO 3 − ) derived from carbon dioxide and water are present on the surface of the solid electrolyte and / or the surface of the metal oxide. It is thought to be formed in. Then, the dissociation equilibrium of the hydrogen carbonate ion is converted into the activity of the mobile ion of the electrolyte, and the change in the carbon dioxide concentration is detected as the electromotive force. When NASICON is used as the solid electrolyte, Na + , which is a mobile ion in the electrolyte, is attracted to HCO 3 − regardless of whether HCO 3 − is formed on the surface of the solid electrolyte or the surface of the metal oxide, and it is in the vicinity of the detection electrode. Moving. Also, H on the surface of the metal oxide with excellent ionic conductivity
When CO 3 − is formed, N, which is a mobile ion in the electrolyte, is formed.
a + penetrates into the metal oxide layer. At this time, NaHC
O 3 may be generated in some cases.
【0048】炭酸水素イオンが電子伝導性に優れる金属
酸化物表面に形成される場合、金属酸化物が導電体とし
て作用し、起電力が発生する。電子伝導性に優れる金属
酸化物としては、例えば、酸化インジウム、酸化スズ、
酸化コバルト、酸化タングステン、酸化亜鉛、酸化鉛、
酸化銅、酸化鉄、酸化ニッケル、酸化クロム等が挙げら
れる。When hydrogencarbonate ions are formed on the surface of a metal oxide having excellent electron conductivity, the metal oxide acts as a conductor and an electromotive force is generated. Examples of the metal oxide having excellent electron conductivity include indium oxide, tin oxide,
Cobalt oxide, tungsten oxide, zinc oxide, lead oxide,
Examples thereof include copper oxide, iron oxide, nickel oxide, and chromium oxide.
【0049】炭酸水素イオンがイオン伝導性に優れる金
属酸化物表面に形成される場合、前述の通り、固体電解
質中の可動イオン種が金属酸化物中に侵入することによ
り、起電力が発生する。イオン伝導性に優れる金属酸化
物としては、例えば、酸化ビスマス、酸化セリウム等が
挙げられる。When hydrogencarbonate ions are formed on the surface of a metal oxide having excellent ionic conductivity, an electromotive force is generated by the penetration of mobile ionic species in the solid electrolyte into the metal oxide, as described above. Examples of the metal oxide having excellent ionic conductivity include bismuth oxide and cerium oxide.
【0050】本発明のセンサは、二酸化炭素存在下で放
置した後、固体電解質、金属酸化物層の赤外吸収スペク
トル(IR)を測定すると、1000cm-1前後(950
〜1050cm-1)に吸収ピークが見られ、HCO3 -の存
在が示唆される。なお、CO3 2-の特性吸収波数の14
00cm-1付近に、吸収は通常見られない。また、このセ
ンサを加熱して放出されるガスを質量分析(MS)する
と、すべてのセンサで、150℃前後をピークに50〜
300℃でH2O(質量数18)、CO2(質量数44)
のピークが同時に検出され、このことからもHCO3 -が
吸着していることが示唆される。応答性の高いセンサほ
ど、IRでHCO3 -に由来する1000cm-1前後のピー
クが大きく、また、MSでH2O、CO2のピーク位置が
一致し、かつ、検出量が多い傾向があり、HCO3 -の存
在がセンサ特性に深く関係していると考えられる。ま
た、同じセンサでも、二酸化炭素濃度の高い雰囲気中で
放置したものほど、IRでHCO3 -に由来する1000
cm-1前後のピークが大きく、また、MSでCO2のピー
ク面積が大きくなる。本発明では、検知極を上記のよう
な組成にすることにより、固体電解質表面および/また
は金属酸化物表面への二酸化炭素由来の炭酸水素イオン
の生成が促進され、感度、応答速度、選択性などの応答
性が著しく向上し、低温での迅速な測定が可能になると
考えられる。なお、形成される炭酸水素イオンは、直接
固体電解質および/または金属酸化物に吸着ないし結合
していても、固体電解質表面および/または金属酸化物
表面の−OH基に直接、または水(H2O)を介して吸
着ないし結合していてもよい。The sensor of the present invention was left in the presence of carbon dioxide, and then the infrared absorption spectrum (IR) of the solid electrolyte and the metal oxide layer was measured to be about 1000 cm -1 (950
~1050cm -1) absorption peaks were observed in, HCO 3 - the presence of which suggests. Note that the characteristic absorption wave number of CO 3 2- is 14
Absorption is usually not seen near 00 cm -1 . Moreover, when the gas released by heating this sensor is subjected to mass spectrometry (MS), all the sensors have a peak at around 150 ° C.
H 2 O (mass number 18), CO 2 (mass number 44) at 300 ° C
Peaks were simultaneously detected, which suggests that HCO 3 − is adsorbed. The higher the responsiveness of the sensor, the larger the IR peak at around 1000 cm -1 due to HCO 3 − , the more consistent the peak positions of H 2 O and CO 2 in MS, and the more the detected amount tends to be. , HCO 3 − is considered to be closely related to the sensor characteristics. Moreover, even with the same sensor, as those left in a high carbon dioxide concentration atmosphere, HCO 3 in IR - from 1000
The peak around cm −1 is large, and the peak area of CO 2 by MS is large. In the present invention, the composition of the sensing electrode as described above promotes the generation of hydrogen carbonate ions derived from carbon dioxide on the surface of the solid electrolyte and / or the surface of the metal oxide, resulting in sensitivity, response speed, selectivity, etc. It is considered that the responsiveness of is significantly improved, and rapid measurement at low temperature becomes possible. Even if the formed hydrogen carbonate ions are directly adsorbed or bound to the solid electrolyte and / or the metal oxide, they may be directly bonded to the -OH group on the surface of the solid electrolyte and / or the surface of the metal oxide or to water (H 2 It may be adsorbed or bound via O).
【0051】<検知極の集電体>本発明の二酸化炭素セ
ンサは、検知極に集電体を用いる。<Collector of Detection Electrode> The carbon dioxide sensor of the present invention uses a collector as a sensing electrode.
【0052】集電体に用いる金属は、金、白金、銀、ル
ビジウム、ロジウム、パラジウム、イリジウム、ニッケ
ル、銅、クロム等のいずれか1種以上であればよい。The metal used for the current collector may be any one or more of gold, platinum, silver, rubidium, rhodium, palladium, iridium, nickel, copper, chromium and the like.
【0053】集電体は多孔質金属であることが好まし
い。集電体が多孔質であると、検知極自体がガス拡散層
として働くため、さらに迅速な応答が得られるようにな
る。The current collector is preferably a porous metal. When the current collector is porous, the sensing electrode itself acts as a gas diffusion layer, so that a quicker response can be obtained.
【0054】多孔質金属としては、金属メッシュ、ある
いは、金属の粉末ペーストを圧着またはスクリーン印刷
して構成する粉末電極が好ましい。特に、粉末電極が好
ましい。金属メッシュは、保持力があればメッシュサイ
ズは特に制限されない。The porous metal is preferably a metal mesh or a powder electrode formed by pressure-bonding or screen-printing a metal powder paste. A powder electrode is particularly preferable. The mesh size of the metal mesh is not particularly limited as long as it has holding power.
【0055】スクリーン印刷とは、金属粉末をペースト
状にしたものをメッシュ状スクリーンを通して基板に塗
布する方法であり、この場合、金属粒子が互いに連結し
た多孔質電極が形成される。このとき使用する金属粉末
の平均粒径は10nm〜100μm 、特に10nm〜10μ
m の範囲であることが、良好な印刷ができるので、好ま
しい。また、ペーストの溶媒としては、用いる金属が溶
解、反応しない有機溶媒で、室温蒸気圧が比較的低く、
作業性がよいものであればよい。特に、α−テルピネオ
ール、エチレングリコール、グリセリン等が好ましい。
スラリーの粘度は0.1〜100,000poiseとする
ことが好ましい。Screen printing is a method in which a paste of metal powder is applied to a substrate through a mesh screen, and in this case, a porous electrode in which metal particles are connected to each other is formed. The average particle size of the metal powder used at this time is 10 nm to 100 μm, especially 10 nm to 10 μm.
The range of m 2 is preferable because good printing can be performed. The paste solvent is an organic solvent in which the metal used does not dissolve or react, and has a relatively low room temperature vapor pressure,
Anything that has good workability may be used. In particular, α-terpineol, ethylene glycol, glycerin and the like are preferable.
The viscosity of the slurry is preferably 0.1 to 100,000 poise.
【0056】また、金属酸化物層の上面に集電体金属粉
末のペーストを塗布し、リードを取ることも好ましい。It is also preferable to apply a paste of current collector metal powder to the upper surface of the metal oxide layer and take a lead.
【0057】多孔質電極の細孔径は0.5〜500μm
が好ましい。The pore size of the porous electrode is 0.5 to 500 μm
Is preferred.
【0058】なお、これらの金属材料をスパッタするこ
とにより、表面が多孔質状態となる電極を形成すること
も可能である。スパッタガスにはAr、He、O2、N2
等のいずれかを用いることが好ましく、成膜中の圧力は
0.1〜500mTorrの範囲が好ましい。また、抵抗加
熱蒸着によっても電極表面を多孔質にすることができ
る。It is also possible to form an electrode having a porous surface by sputtering these metal materials. The sputtering gas is Ar, He, O 2 , N 2
It is preferable to use any of the above, and the pressure during film formation is preferably in the range of 0.1 to 500 mTorr. Also, the electrode surface can be made porous by resistance heating vapor deposition.
【0059】集電体が金属メッシュの場合、金属酸化物
の層の上の所定の位置に金属メッシュを固定した後、炭
酸水素塩粉末および/または炭酸塩粉末のペーストまた
は水溶液、好ましくは水溶液を塗布することが好まし
い。このようにすることで炭酸水素塩および/または炭
酸塩に熱をかけなくてもよくなる。このように金属メッ
シュの上から水溶液等を塗布しても、水溶液等がメッシ
ュの細孔を通り抜け、金属酸化物層に含浸される。When the current collector is a metal mesh, the metal mesh is fixed at a predetermined position on the metal oxide layer, and then a hydrogen carbonate powder and / or a carbonate powder paste or an aqueous solution, preferably an aqueous solution, is applied. It is preferably applied. By doing so, it is not necessary to heat the hydrogen carbonate and / or carbonate. Thus, even if the aqueous solution or the like is applied on the metal mesh, the aqueous solution or the like passes through the pores of the mesh and is impregnated into the metal oxide layer.
【0060】集電体は金属酸化物層を挟んで固体電解質
に対向して設けられていることが好ましい。このような
構造にすることにより、検知極自体がガス拡散層として
働くために、さらに迅速な応答が得られるようになる。It is preferable that the current collector is provided so as to face the solid electrolyte with the metal oxide layer interposed therebetween. With such a structure, the sensing electrode itself functions as a gas diffusion layer, so that a quicker response can be obtained.
【0061】<対極>本発明の二酸化炭素センサでは、
対極に金属または金属酸化物を用いる。用いる金属また
は金属酸化物は、上述の検知極の集電体と同じ金属また
はそれらの酸化物、金属酸化物層と同じ金属酸化物のい
ずれか1種以上であればよい。対極に金属酸化物を用い
ることにより、共存ガスの影響が軽減し、高い二酸化炭
素選択性が得られる。また、耐湿性が向上し、特に低温
での測定時の湿度の影響が軽減する。<Counter electrode> In the carbon dioxide sensor of the present invention,
A metal or metal oxide is used for the counter electrode. The metal or metal oxide used may be any one or more of the same metals or their oxides as the current collector of the above-mentioned sensing electrode, and the same metal oxides as the metal oxide layer. By using a metal oxide for the counter electrode, the effect of coexisting gas is reduced and high carbon dioxide selectivity is obtained. In addition, the moisture resistance is improved, and the influence of humidity is reduced especially when measuring at low temperatures.
【0062】対極は、集電体と同じく、多孔質金属また
は多孔質金属酸化物が好ましい。特に、金属酸化物の粉
末ペーストを圧着またはスクリーン印刷して構成する粉
末電極が好ましい。金属メッシュは、保持力があればメ
ッシュサイズは特に制限されない。粉末電極を形成する
ためのペーストに用いる金属粉末、金属酸化物粉末の平
均粒径は10nm〜100μm 、特に10nm〜10μm が
好ましい。また、ペーストの溶媒としては、用いる金属
または金属酸化物が溶解、反応しない有機溶媒で、室温
蒸気圧が比較的低く、作業性がよいものであればよい。
特に、α−テルピネオール、エチレングリコール、グリ
セリン等が好ましい。スラリーの粘度は0.1〜10
0,000poiseとすることが好ましい。The counter electrode is preferably a porous metal or a porous metal oxide, like the current collector. In particular, a powder electrode formed by pressure-bonding or screen-printing a metal oxide powder paste is preferable. The mesh size of the metal mesh is not particularly limited as long as it has holding power. The average particle size of the metal powder and the metal oxide powder used in the paste for forming the powder electrode is preferably 10 nm to 100 μm, and particularly preferably 10 nm to 10 μm. The solvent of the paste may be an organic solvent in which the metal or metal oxide used does not dissolve or react, and has a relatively low room temperature vapor pressure and good workability.
In particular, α-terpineol, ethylene glycol, glycerin and the like are preferable. The viscosity of the slurry is 0.1-10
It is preferable to set it as 10,000 poise.
【0063】多孔質電極の細孔径は0.5〜500μm
が好ましい。The pore diameter of the porous electrode is 0.5 to 500 μm.
Is preferred.
【0064】<センサ構造>本発明の二酸化炭素センサ
の構成例を、図1、2に示す。図1は、固体電解質2を
挟んで、金属酸化物層4と集電体5とから成る検知極3
および対極6を対向して設けている分離型の二酸化炭素
センサ1である。金属酸化物層4は、導電性金属酸化物
および炭酸水素イオンを含有する。図2は、金属酸化物
層4と集電体5とから成る検知極3および対極6を固体
電解質2の一方の面上に設けている非分離型の二酸化炭
素センサ1である。非分離型は、集電体の形成やリード
の取り出しをプロセス上簡便にでき、製造工程が簡略化
されるので、生産効率が高くなり、好ましい。また、素
子の小型化が可能である。検知極3および対極6からは
それぞれリード線が引き出されて、電位差計に接続され
ている。<Sensor Structure> FIGS. 1 and 2 show a structural example of the carbon dioxide sensor of the present invention. FIG. 1 shows a detection electrode 3 composed of a metal oxide layer 4 and a current collector 5 with a solid electrolyte 2 interposed therebetween.
Also, it is a separation type carbon dioxide sensor 1 provided with a counter electrode 6 facing each other. The metal oxide layer 4 contains a conductive metal oxide and hydrogen carbonate ions. FIG. 2 shows a non-separable carbon dioxide sensor 1 in which a detection electrode 3 composed of a metal oxide layer 4 and a current collector 5 and a counter electrode 6 are provided on one surface of a solid electrolyte 2. The non-separable type is preferable because the current collector can be formed and the leads can be taken out easily in the process and the manufacturing process can be simplified, resulting in high production efficiency. Further, the element can be downsized. Lead wires are respectively drawn from the detection electrode 3 and the counter electrode 6 and are connected to the potentiometer.
【0065】本発明の二酸化炭素センサは、湿度の影響
を極力防ぐために検知極表面以外は測定雰囲気に触れな
いような構成とすることが好ましい。例えば、検知極表
面以外をテフロン等の樹脂または無機セラミックスで被
覆したり、または、参照ガスが封入されたガラス管のよ
うなもので被覆したりすることが好ましい。The carbon dioxide sensor of the present invention is preferably constructed so that the measurement atmosphere is not exposed except for the surface of the detection electrode in order to prevent the influence of humidity as much as possible. For example, it is preferable that the surface other than the detection electrode surface is coated with a resin such as Teflon or an inorganic ceramics, or with a glass tube in which a reference gas is sealed.
【0066】本発明の二酸化炭素センサの寸法は特に限
定されないが、検知極が形成される表面を固体電解質の
上面としたとき、通常、固体電解質の厚さは1μm〜5m
m程度、固体電解質の上面の面積は1μm2〜200mm2程
度である。また、検知極の厚さは0.1〜100μm程
度、検知極の面積は0.5μm2〜200mm2程度であ
る。また、対極の厚さは0.1〜100μm程度、対極
の面積は0.5μm2〜200mm2程度である。The size of the carbon dioxide sensor of the present invention is not particularly limited, but when the surface on which the detection electrode is formed is the upper surface of the solid electrolyte, the thickness of the solid electrolyte is usually 1 μm to 5 m.
The area of the upper surface of the solid electrolyte is about 1 μm 2 to 200 mm 2 . The thickness of the detection electrode is about 0.1 to 100 μm, and the area of the detection electrode is about 0.5 μm 2 to 200 mm 2 . The thickness of the counter electrode is about 0.1 to 100 μm, and the area of the counter electrode is about 0.5 μm 2 to 200 mm 2 .
【0067】本発明の二酸化炭素センサの最適作動温度
は、センサ素子を構成する材料や共存ガスの種類等によ
っても異なるが、炭酸水素イオンが分解しない温度範
囲、すなわち−70℃〜200℃、好ましくは−70℃
〜150℃、より好ましくは−50℃〜120℃の範囲
である。高温で測定不能になったセンサも、室温程度ま
で温度を下げると性能が回復し、応答が見られるように
なる。本発明の二酸化炭素センサは、従来の固体電解質
を用いた二酸化炭素センサよりも低温で作動することが
でき、消費電力の低減が可能である。また、高温にしな
くてよいので、ヒータの熱による測定環境の変化も十分
小さくすることができる。The optimum operating temperature of the carbon dioxide sensor of the present invention varies depending on the material constituting the sensor element, the type of coexisting gas, etc., but the temperature range in which hydrogen carbonate ions are not decomposed, that is, -70 to 200 ° C, preferably Is -70 ° C
˜150 ° C., more preferably −50 ° C. to 120 ° C. For the sensor that cannot be measured at high temperature, the performance will be restored and the response will be seen when the temperature is lowered to about room temperature. The carbon dioxide sensor of the present invention can operate at a lower temperature than a conventional carbon dioxide sensor using a solid electrolyte and can reduce power consumption. Further, since the temperature does not have to be high, the change in the measurement environment due to the heat of the heater can be sufficiently reduced.
【0068】また、本発明の二酸化炭素センサは、応答
性もよく、1秒〜4分、好ましくは1秒〜3分で応答が
得られる。Further, the carbon dioxide sensor of the present invention has good responsiveness, and a response is obtained in 1 second to 4 minutes, preferably 1 second to 3 minutes.
【0069】素子構成において、ヒーターは室温作動可
能なセンサにおいては不要であるが、季節による温度差
を考慮するとヒーターをつけることが好ましい。In the element structure, the heater is not necessary for the sensor operable at room temperature, but it is preferable to attach the heater in consideration of the temperature difference depending on the season.
【0070】[0070]
【実施例】<実施例1>固体電解質のNASICONペ
レット(10mm径、1mm厚さ)の下面には、Ptペース
トでPtメッシュ(100メッシュ)を固定して900
℃で焼成し、対極とした。EXAMPLES Example 1 A Pt mesh (100 mesh) was fixed with a Pt paste on the lower surface of a solid electrolyte NASICON pellet (10 mm diameter, 1 mm thickness) to obtain 900
It was fired at ℃ and made a counter electrode.
【0071】表1に示す金属酸化物粉末(平均粒径:1
0nm〜100μm)50mgにα−テルピネオールを50w
t%加えてよく混合し、ペースト状にした。このペース
トの粘度は10,000〜100,000poiseだっ
た。そして、このペーストを固体電解質のNASICO
Nペレットの上面に塗布し、650℃で2時間加熱処理
した。そして、その上面に集電体のAuメッシュ(10
0メッシュ)を設けた。さらに、炭酸水素ナトリウム粉
末10mgを水に溶解して1.0wt%の炭酸水素ナトリウ
ム水溶液を調製し、Auメッシュの上面から塗布し、含
浸させた後、50℃で1時間加熱処理して乾燥させて検
知極とした。Metal oxide powders shown in Table 1 (average particle size: 1
0 nm to 100 μm) 50 mg of α-terpineol to 50 w
t% was added and mixed well to form a paste. The viscosity of this paste was 10,000-100,000 poise. Then, this paste is used as a solid electrolyte NASICO.
It was applied on the upper surface of N pellets and heat-treated at 650 ° C. for 2 hours. Then, the Au mesh (10
0 mesh). Further, 10 mg of sodium hydrogencarbonate powder was dissolved in water to prepare a 1.0 wt% sodium hydrogencarbonate aqueous solution, which was applied from the upper surface of the Au mesh, impregnated, and then heat-treated at 50 ° C. for 1 hour to be dried. And made it the detection pole.
【0072】最後に、検知極表面だけが露出するよう
に、対極側に乾燥標準空気を封入したガラス管を無機接
着剤(東亞合成化学社製、アロンセラミックC)で接着
して被覆した。Finally, a glass tube in which dry standard air was sealed on the counter electrode side was adhered and covered with an inorganic adhesive (Aron Ceramic C, manufactured by Toagosei Kagaku Co., Ltd.) so that only the surface of the detection electrode was exposed.
【0073】そして、それぞれの電極からリード線を接
続し、図1のような分離型の二酸化炭素センサ(No.1
〜20)を得た。Then, the lead wires are connected from the respective electrodes to separate the carbon dioxide sensor (No. 1) as shown in FIG.
~ 20) was obtained.
【0074】室温(25℃)において、乾燥空気中で各
種CO2濃度の被検ガスを流通させた測定セル中に作製
した二酸化炭素センサを挿入し、CO2濃度に対して発
生する起電力値の特性を測定した。検知極の導電性金属
酸化物にIn2O3を用いた二酸化炭素センサ(集電体が
メッシュ電極のNo.1のセンサ)の結果を図3に示す。At room temperature (25 ° C.), the carbon dioxide sensor produced was inserted into a measuring cell in which test gases of various CO 2 concentrations were passed in dry air, and the electromotive force value generated with respect to the CO 2 concentration was inserted. Was measured. The results of the carbon dioxide sensor using In 2 O 3 as the conductive metal oxide of the detection electrode (No. 1 sensor in which the current collector is a mesh electrode) are shown in FIG.
【0075】室温(25℃)において、乾燥空気中でC
O2濃度1000ppmの被検ガスを流通させた測定セル中
に作製した二酸化炭素センサを挿入し、応答速度、感度
を調べた。さらに、環境基準濃度に希釈したNO、NO
2、COのそれぞれのガスを流通させて応答を確認し、
選択性を調べた。その結果を表1に示す。C at room temperature (25 ° C.) in dry air
The prepared carbon dioxide sensor was inserted into a measurement cell in which a test gas having an O 2 concentration of 1000 ppm was passed, and the response speed and sensitivity were examined. Furthermore, NO, NO diluted to the environmental standard concentration
2 Confirm the response by circulating each gas of CO
The selectivity was investigated. The results are shown in Table 1.
【0076】[0076]
【表1】 [Table 1]
【0077】応答速度は、CO2ガス導入後、応答が一
定になったときの起電力値の90%になるのに要する時
間である。評価は
◎:1分以内
○:1分超3分以内
△:3分超5分以内
×:5分超
とした。The response speed is the time required to reach 90% of the electromotive force value when the response becomes constant after the introduction of CO 2 gas. The evaluation was ◎: within 1 minute ○: over 1 minute within 3 minutes △: over 3 minutes within 5 minutes ×: over 5 minutes
【0078】感度は、CO2ガス導入前の起電力値と導
入後の起電力値との差である。評価は
◎:25mV以上
○:15mV以上25mV未満
△:5mV以上15mV未満
×:5mV未満
とした。The sensitivity is the difference between the electromotive force value before introduction of CO 2 gas and the electromotive force value after introduction. The evaluation was ⊚: 25 mV or more, ◯: 15 mV or more and less than 25 mV Δ: 5 mV or more and less than 15 mV ×: less than 5 mV.
【0079】選択性は、CO2ガス以外の共存ガスの影
響を受けない性質である。評価は
◎:すべての共存ガスの影響を受けないもの
○:2種類の共存ガスの影響を受けないもの
△:1種類の共存ガスの影響を受けないもの
×:すべての共存ガスの影響を受けるもの
とした。Selectivity is a property that is not affected by coexisting gases other than CO 2 gas. Evaluation: ◎: Unaffected by all coexisting gases ○: Unaffected by two types of coexisting gas △: Unaffected by one type of coexisting gas ×: Influenced by all coexisting gases I decided.
【0080】<実施例2>検知極の集電体にAuメッシ
ュを設ける代わりに、金属酸化物層の上面に、Au粉末
(平均粒径:0.1〜100μm)50mgにα−テルピ
ネオールを50wt%加えたペースト(粘度10,000
〜100,000poise)を塗布し、700℃で2時間
加熱処理して多孔質の粉末電極を設けた他は、実施例1
と同様にして分離型の二酸化炭素センサ(No.1〜2
0)を作製し、実施例1と同様に評価した。その結果を
表1に示す。Example 2 Instead of providing an Au mesh on the collector of the detection electrode, 50 mg of Au powder (average particle size: 0.1 to 100 μm) and 50 wt% of α-terpineol were placed on the upper surface of the metal oxide layer. % Added paste (viscosity 10,000
Example 1 except that 100 to 100,000 poise) was applied and heat treatment was performed at 700 ° C. for 2 hours to provide a porous powder electrode.
Separate type carbon dioxide sensor (No. 1-2
0) was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.
【0081】実施例1、2において、金属酸化物として
酸化セリウム(CeO2)を検知極に用いた二酸化炭素
センサ、酸化プラセオジム(Pr6O11)を検知極に用
いた二酸化炭素センサ、酸化ネオジム(Nd2O3)を検
知極に用いた二酸化炭素センサも、酸化ランタン(La
2O3)を検知極に用いた二酸化炭素センサ(No.17)
と同等の結果が得られた。In Examples 1 and 2, a carbon dioxide sensor using cerium oxide (CeO 2 ) as a metal oxide as a detection electrode, a carbon dioxide sensor using praseodymium oxide (Pr 6 O 11 ) as a detection electrode, and neodymium oxide. A carbon dioxide sensor using (Nd 2 O 3 ) as a detection electrode is also used for lanthanum oxide (La).
Carbon dioxide sensor (No. 17) using 2 O 3 ) as the detection electrode
The same result was obtained.
【0082】また、金属酸化物として酸化銅(CuO)
に酸化マグネシウム(MgO)を5wt%添加したものを
検知極に用いた二酸化炭素センサ、酸化銅(CuO)に
酸化ストロンチウム(SrO)を5wt%添加したものを
検知極に用いた二酸化炭素センサ、酸化銅(CuO)に
酸化バリウム(BaO)を5wt%添加したものを検知極
に用いた二酸化炭素センサも、酸化銅(CuO)に酸化
カルシウム(CaO)を5wt%添加した二酸化炭素セン
サ(No.19)と同等の結果が得られた。Copper oxide (CuO) is used as the metal oxide.
Carbon dioxide sensor with 5 wt% magnesium oxide (MgO) added to the sensing electrode, carbon dioxide sensor with 5 wt% strontium oxide (SrO) added to copper oxide (CuO) as the sensing electrode, oxidation A carbon dioxide sensor using 5 wt% of barium oxide (BaO) added to copper (CuO) as a detection electrode is also a carbon dioxide sensor (No. 19) of 5 wt% calcium oxide (CaO) added to copper oxide (CuO). The same result was obtained.
【0083】金属酸化物として酸化銅(CuO)に酸化
リチウム(Li2O)を5wt%添加したものを検知極に
用いた二酸化炭素センサ、酸化銅(CuO)に酸化カリ
ウム(K2O)を5wt%添加したものを検知極に用いた
二酸化炭素センサ、酸化銅(CuO)に酸化ルビジウム
(Rb2O)を5wt%添加したものを検知極に用いた二
酸化炭素センサ、酸化銅(CuO)に酸化セシウム(C
s2O)を5wt%添加したものを検知極に用いた二酸化
炭素センサも、酸化銅(CuO)に酸化ナトリウム(N
a2O)を5wt%添加した二酸化炭素センサ(No.20)
と同等の結果が得られた。As a metal oxide, a carbon dioxide sensor using copper oxide (CuO) to which 5 wt% of lithium oxide (Li 2 O) is added as a detection electrode, and copper oxide (CuO) containing potassium oxide (K 2 O) is used. A carbon dioxide sensor using 5 wt% added to the detection electrode, a carbon dioxide sensor using copper oxide (CuO) added with 5 wt% rubidium oxide (Rb 2 O) to the detection electrode, copper oxide (CuO) Cesium oxide (C
The carbon dioxide sensor using 5 wt% s 2 O) added to the detection electrode is also used for copper oxide (CuO) and sodium oxide (N
Carbon dioxide sensor (No. 20) with 5 wt% a 2 O added
The same result was obtained.
【0084】また、他のNaCl型酸化物、スピネル型酸化
物、ペロブスカイト型酸化物、層状ペロブスカイト型酸
化物、パイロクロア型酸化物、その他の酸化物を金属酸
化物として用いても同様の効果が得られた。The same effect can be obtained by using other NaCl type oxides, spinel type oxides, perovskite type oxides, layered perovskite type oxides, pyrochlore type oxides, and other oxides as metal oxides. Was given.
【0085】また、実施例1、2において、炭酸水素ナ
トリウムの代わりに、炭酸水素リチウム、炭酸水素カリ
ウムを用いても同等の結果が得られた。炭酸水素ナトリ
ウムの代わりに、炭酸水素ルビジウム、炭酸水素セシウ
ム、炭酸水素マグネシウム、炭酸水素カルシウムを用い
ても同様の効果が得られた。Further, in Examples 1 and 2, the same results were obtained even when lithium hydrogen carbonate or potassium hydrogen carbonate was used instead of sodium hydrogen carbonate. Similar effects were obtained by using rubidium hydrogen carbonate, cesium hydrogen carbonate, magnesium hydrogen carbonate, or calcium hydrogen carbonate instead of sodium hydrogen carbonate.
【0086】<比較例1>検知極材料に表2に示す金属
炭酸塩粉末を用い、NASICONペレットの上面に融
着し、集電体を設けた他は、実施例1、2と同様にして
分離型の二酸化炭素センサ(No.21〜23)を作製
し、実施例1と同様に評価した。その結果を表2に示
す。<Comparative Example 1> The same procedure as in Examples 1 and 2 was repeated except that the metal carbonate powder shown in Table 2 was used as the sensing electrode material, the fusion was performed on the upper surface of the NASICON pellets, and a current collector was provided. Separate type carbon dioxide sensors (Nos. 21 to 23) were produced and evaluated in the same manner as in Example 1. The results are shown in Table 2.
【0087】<比較例2>検知極材料に表2に示す金属
酸化物粉末を用い、炭酸水素ナトリウム水溶液を塗布し
なかった他は、実施例1、2と同様にして分離型の二酸
化炭素センサ(No.24〜29)を作製し、実施例1と
同様に評価した。その結果を表2に示す。また、検知極
にPbOとAuメッシュとを用いた二酸化炭素センサ
(集電体がメッシュ電極のNo.24のセンサ)の室温
(25℃)におけるCO2濃度に対する出力起電力値の
特性図を図3に示す。Comparative Example 2 A separation type carbon dioxide sensor was prepared in the same manner as in Examples 1 and 2 except that the metal oxide powder shown in Table 2 was used as the detection electrode material and the aqueous sodium hydrogen carbonate solution was not applied. (Nos. 24-29) were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2. In addition, a characteristic diagram of the output electromotive force value with respect to the CO 2 concentration at room temperature (25 ° C.) of a carbon dioxide sensor using PbO and Au mesh for the detection electrode (sensor No. 24 with a mesh electrode as a current collector) is shown. 3 shows.
【0088】[0088]
【表2】 [Table 2]
【0089】本発明の二酸化炭素センサは、比較例のも
のよりも応答速度、感度、選択性すべてに優れていた。The carbon dioxide sensor of the present invention was superior to the comparative example in all in response speed, sensitivity and selectivity.
【0090】また、集電体が粉末電極であるセンサは、
メッシュ電極のものよりも応答が迅速で、特に感度が高
かった。Further, the sensor in which the current collector is a powder electrode is
The response was quicker than that of the mesh electrode, and the sensitivity was particularly high.
【0091】<実施例3>ペレットの上面、つまり検知
極と同一面内の固体電解質表面に、実施例1と同様にし
てPtメッシュ(100メッシュ)を検知極と接しない
ように設けて対極とした。<Example 3> A Pt mesh (100 mesh) was provided on the upper surface of the pellet, that is, the surface of the solid electrolyte in the same plane as the detection electrode so as not to contact the detection electrode in the same manner as in Example 1 to form a counter electrode. did.
【0092】表3に示す金属酸化物粉末(平均粒径:1
0nm〜100μm)50mgにα−テルピネオールを50w
t%加えてよく混合し、ペースト状にした。このペース
トの粘度は10,000〜100,000poiseだっ
た。そして、このペーストを固体電解質のNASICO
Nペレット(10mm径、1mm厚さ)の上面約半分に塗布
し、650℃で2時間加熱処理した。そして、その金属
酸化物層の上面に集電体のAuメッシュ(100メッシ
ュ)を設けた。さらに、炭酸水素ナトリウム粉末10mg
を水に溶解して1.0wt%の炭酸水素ナトリウム水溶液
を調製し、Auメッシュの上面から塗布し、含浸させた
後、50℃で1時間加熱処理して乾燥させて検知極とし
た。Metal oxide powders shown in Table 3 (average particle size: 1
0 nm to 100 μm) 50 mg of α-terpineol to 50 w
t% was added and mixed well to form a paste. The viscosity of this paste was 10,000-100,000 poise. Then, this paste is used as a solid electrolyte NASICO.
N pellets (10 mm diameter, 1 mm thickness) were applied to about half of the upper surface and heat treated at 650 ° C. for 2 hours. Then, an Au mesh (100 mesh) as a current collector was provided on the upper surface of the metal oxide layer. Furthermore, sodium hydrogen carbonate powder 10 mg
Was dissolved in water to prepare a 1.0 wt% sodium hydrogen carbonate aqueous solution, which was applied from the upper surface of the Au mesh, impregnated with it, and then heat-treated at 50 ° C. for 1 hour and dried to obtain a detection electrode.
【0093】そして、それぞれの電極からリード線を接
続し、図2のような非分離型の二酸化炭素センサ(No.
30〜36)を得た。Then, a lead wire is connected from each electrode, and a non-separable carbon dioxide sensor (No.
30-36) was obtained.
【0094】この二酸化炭素センサを実施例1と同様に
評価した。その結果を表3に示す。This carbon dioxide sensor was evaluated in the same manner as in Example 1. The results are shown in Table 3.
【0095】<実施例4>検知極の集電体にAuメッシ
ュを設ける代わりに、金属酸化物層の上面に、Au粉末
(平均粒径:0.1〜100μm)50mgにα−テルピ
ネオールを50wt%加えたペースト(粘度10,000
〜100,000poise)を塗布し、700℃で2時間
加熱処理して多孔質の粉末電極を設けた他は、実施例3
と同様にして非分離型の二酸化炭素センサ(No.30〜
36)を作製し、実施例3と同様に評価した。その結果
を表3に示す。Example 4 Instead of providing an Au mesh on the current collector of the detection electrode, 50 mg of Au powder (average particle size: 0.1 to 100 μm) and 50 wt% of α-terpineol were placed on the upper surface of the metal oxide layer. % Added paste (viscosity 10,000
Example 3 except that a porous powder electrode was provided by applying heat treatment at 700 ° C. for 2 hours.
Non-separable carbon dioxide sensor (No. 30 ~
36) was prepared and evaluated in the same manner as in Example 3. The results are shown in Table 3.
【0096】[0096]
【表3】 [Table 3]
【0097】非分離型の二酸化炭素センサは、分離型の
ものと同等の結果が得られた。With the non-separation type carbon dioxide sensor, the same result as that of the separation type was obtained.
【0098】また、非分離型の二酸化炭素センサでも、
集電体が粉末電極であるセンサは、メッシュ電極のもの
よりも応答が迅速で、特に感度が高かった。In addition, even with a non-separation type carbon dioxide sensor,
The sensor in which the current collector was a powder electrode had a quicker response and was particularly sensitive than that of a mesh electrode.
【0099】<実施例5>ペレットの上面、つまり検知
極と同一面内の固体電解質表面に、実施例1と同様にし
てPtメッシュ(100メッシュ)を検知極と接しない
ように設けて対極とした。<Example 5> A Pt mesh (100 mesh) was provided on the upper surface of the pellet, that is, on the surface of the solid electrolyte in the same plane as the detection electrode so as not to contact the detection electrode in the same manner as in Example 1 to form a counter electrode. did.
【0100】表4に示すIn2O3粉末(平均粒径:50
nm)、またはIn2O3にWO3を5wt%加えた粉末(平
均粒径:50nm)50mgにα−テルピネオールを50wt
%加えてよく混合し、ペースト状にした。そして、この
ペーストを固体電解質のNASICONペレット(10
mm径、1mm厚さ)の上面約半分に塗布し、650℃で2
時間加熱処理した。そして、その金属酸化物層の上面に
集電体のAuメッシュ(100メッシュ)を設けた。さ
らに、炭酸水素ナトリウム粉末10mgを水に溶解して
1.0wt%の炭酸水素ナトリウム水溶液を調製し、Au
メッシュの上面から塗布し、含浸させた後、50℃で1
時間加熱処理して乾燥させて検知極とした。In 2 O 3 powder (average particle size: 50) shown in Table 4
nm) or 50 mg of powder obtained by adding 5 wt% of WO 3 to In 2 O 3 (average particle size: 50 nm) and 50 wt of α-terpineol.
% And mixed well to form a paste. Then, this paste is used as a solid electrolyte NASICON pellet (10
(mm diameter, 1 mm thickness), apply it on about half of the upper surface and apply 2 at 650 ° C.
Heat treated for hours. Then, an Au mesh (100 mesh) as a current collector was provided on the upper surface of the metal oxide layer. Further, 10 mg of sodium hydrogen carbonate powder was dissolved in water to prepare a 1.0 wt% sodium hydrogen carbonate aqueous solution.
Apply from the top surface of the mesh, impregnate it, and then 1
It was heat-treated for a period of time and dried to form a detection electrode.
【0101】そして、それぞれの電極からリード線を接
続し、図2のような非分離型の二酸化炭素センサ(No.
37、38)を得た。Then, a lead wire is connected from each electrode, and a non-separable carbon dioxide sensor (No.
37, 38) was obtained.
【0102】この二酸化炭素センサを実施例1と同様に
評価した。その結果を表4に示す。This carbon dioxide sensor was evaluated in the same manner as in Example 1. The results are shown in Table 4.
【0103】<実施例6>対極にPtメッシュを設ける
代わりに、NASICONペレットの上面に、In2O3
粉末(平均粒径:50nm)50mgにα−テルピネオール
を50wt%加えたペーストを塗布し、650℃で2時間
加熱処理して多孔質の粉末電極を設けた他は、実施例5
と同様にして非分離型の二酸化炭素センサ(No.39)
を作製し、実施例1と同様に評価した。その結果を表4
に示す。Example 6 Instead of providing a Pt mesh on the counter electrode, In 2 O 3 was formed on the upper surface of the NASICON pellets.
Example 5 was repeated except that 50 mg of powder (average particle size: 50 nm) was coated with a paste containing 50% by weight of α-terpineol and heat-treated at 650 ° C. for 2 hours to provide a porous powder electrode.
Non-separable carbon dioxide sensor (No. 39)
Was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 4.
Shown in.
【0104】[0104]
【表4】 [Table 4]
【0105】対極に金属酸化物を用いることにより、選
択性が向上した。The selectivity was improved by using the metal oxide as the counter electrode.
【0106】また、本発明の二酸化炭素センサの耐湿性
を調べた。Further, the moisture resistance of the carbon dioxide sensor of the present invention was examined.
【0107】検知極がIn2O3、NaHCO3とAuメ
ッシュとから成り、対極がPtメッシュである分離型の
二酸化炭素センサ(集電体がメッシュ電極のNo.1のセン
サ)を相対湿度80%雰囲気下に24時間保管した後、
基準ガス中の起電力値の時間変化について調べた。その
結果を図4に示す。この二酸化炭素センサは1日あれば
十分な性能の復帰を示した。A separation type carbon dioxide sensor (No. 1 sensor having a mesh electrode as a current collector) having a detection electrode made of In 2 O 3 , NaHCO 3 and Au mesh and a counter electrode made of Pt mesh was used. % After storing in an atmosphere for 24 hours,
The time variation of the electromotive force value in the reference gas was investigated. The result is shown in FIG. The carbon dioxide sensor showed a satisfactory return in one day.
【0108】検知極がIn2O3、WO3、NaHCO3と
Auメッシュとから成り、対極がIn2O3粉末電極であ
る非分離型の二酸化炭素センサ(集電体がメッシュ電極
のNo.39のセンサ)を相対湿度80%雰囲気下に24時
間保管した後、基準ガス中の起電力値の時間変化につい
て調べた。その結果を図5に示す。この二酸化炭素セン
サは非常に早い性能の復帰を示した。A non-separation type carbon dioxide sensor in which the detection electrode is composed of In 2 O 3 , WO 3 , NaHCO 3 and Au mesh and the counter electrode is an In 2 O 3 powder electrode (current collector is No. of mesh electrode). 39 sensors) were stored in an atmosphere of 80% relative humidity for 24 hours, and then the time variation of the electromotive force value in the reference gas was examined. The result is shown in FIG. This carbon dioxide sensor showed a very fast recovery of performance.
【0109】検知極がNa2CO3とAuメッシュとから
成り、対極がPtメッシュである分離型の二酸化炭素セ
ンサ(集電体がメッシュ電極のNo.21のセンサ)を相対
湿度80%雰囲気下に24時間保管した後、基準ガス中
の電圧値の時間変化について調べた。その結果を図6に
示す。この二酸化炭素センサは性能の復帰に1日以上の
時間を要した。本発明の二酸化炭素センサは湿度の影響
が軽減されていることがわかる。A separation type carbon dioxide sensor (a sensor of No. 21 having a mesh electrode as a current collector) in which the detection electrode is composed of Na 2 CO 3 and Au mesh and the counter electrode is Pt mesh is used in an atmosphere of 80% relative humidity. After storing at 24 hours for 24 hours, the time variation of the voltage value in the reference gas was examined. The result is shown in FIG. This carbon dioxide sensor required more than one day to recover its performance. It can be seen that the carbon dioxide sensor of the present invention is less affected by humidity.
【0110】<比較例3>集電体をAuメッシュ(10
0メッシュ)の代わりに、Au薄膜とし、金属酸化物層
を覆ってしまった他は、実施例1と同様にして分離型の
二酸化炭素センサを作製し、実施例1と同様に評価し
た。<Comparative Example 3> The current collector was made of Au mesh (10
Instead of (0 mesh), an Au thin film was used to cover the metal oxide layer, and a separation type carbon dioxide sensor was produced in the same manner as in Example 1 and evaluated in the same manner as in Example 1.
【0111】この二酸化炭素センサは、CO2応答がほ
とんど確認されなかった。これは、集電体であるAu薄
膜が表面を覆ってしまって、CO2が金属酸化物層に拡
散しないためと推測される。The carbon dioxide sensor showed almost no CO 2 response. It is presumed that this is because the Au thin film as the current collector covers the surface and CO 2 does not diffuse into the metal oxide layer.
【0112】<比較例4>検知極にIn2O3とNaHC
O3を用い、対極表面を乾燥標準空気を封入したガラス
管で被覆しなかった他は、実施例1と同様にして分離型
の二酸化炭素センサを作製し、実施例1と同様に評価し
た。<Comparative Example 4> In 2 O 3 and NaHC were used for the detection electrode.
A separation type carbon dioxide sensor was produced in the same manner as in Example 1 except that O 3 was used and the surface of the counter electrode was not covered with a glass tube in which dry standard air was sealed, and was evaluated in the same manner as in Example 1.
【0113】このセンサは、NO、COについては応答
が確認されず、本発明のセンサのCO2選択性が確認さ
れた。No response was confirmed for this sensor with respect to NO and CO, and the CO 2 selectivity of the sensor of the present invention was confirmed.
【0114】<実施例7>それぞれのセンサについて、
乾燥空気中、CO2濃度10000ppmの被検ガス中に放
置した後、センサの固体電解質、金属酸化物層の赤外吸
収スペクトルを測定した。測定は、Nicolet社製 FT-
IR 20SXB を用いて、全反射法により測定した。<Embodiment 7> For each sensor,
After being left in a test gas having a CO 2 concentration of 10,000 ppm in dry air, infrared absorption spectra of the solid electrolyte and the metal oxide layer of the sensor were measured. Measurement is Nicolet FT-
It measured by the total reflection method using IR20SXB.
【0115】応答の良好なセンサ、特にNo.1〜3のセ
ンサでは、1000cm-1前後(950〜1050cm-1)
に明確な吸収ピークが見られ、炭酸水素イオン(HCO
3 -)の存在が示唆された。本発明の他のセンサでも、こ
のピークは見られた。金属酸化物層のIRスペクトルで
も、含有する炭酸水素塩のピークよりも大きくなってい
た。また、ともに、CO3 2-の特性吸収波数の1400c
m-1付近に、吸収は見られなかった。比較例のセンサに
ついては、検知極に金属酸化物のみを用いたセンサ(N
o.24〜29)では、HCO3 -に由来する1000cm-1
前後のピークは見られず、検知極に金属炭酸塩を用いた
センサ(No.21〜23)では、このピークは本発明の
センサと比べて非常に小さかった。検知極の金属酸化物
層に炭酸水素塩を含有している本発明のセンサは、固体
電解質表面、金属酸化物表面に炭酸水素イオンが速やか
に形成され、金属酸化物のみのものよりも応答が迅速に
なったことが示唆される。The sensors with good response, especially No. 1 to 3 sensors, have a size of around 1000 cm -1 (950 to 1050 cm -1 ).
A clear absorption peak is seen in the
3 - The presence of) has been suggested. This peak was also seen with the other sensors of the present invention. The IR spectrum of the metal oxide layer was also larger than the peak of the hydrogen carbonate contained. In addition, both have a characteristic absorption wave number of CO 3 2- of 1400c.
No absorption was observed near m -1 . Regarding the sensor of the comparative example, a sensor using only a metal oxide for the detection electrode (N
24 to 29), 1000 cm −1 derived from HCO 3 −
No peaks before and after were seen, and in the sensor using the metal carbonate as the detection electrode (No. 21 to 23), this peak was very small as compared with the sensor of the present invention. The sensor of the present invention which contains a hydrogen carbonate in the metal oxide layer of the detection electrode, hydrogen carbonate ions are rapidly formed on the solid electrolyte surface and the metal oxide surface, and the response is higher than that of the metal oxide alone. It is suggested that it has become quick.
【0116】さらに、No.1〜3のセンサについて、乾
燥空気中、CO2濃度350ppmの被検ガス中に放置した
後、センサの固体電解質、金属酸化物層の赤外吸収スペ
クトルを測定したところ、HCO3 -に由来する1000
cm-1前後のピークは、CO2濃度10000ppmの被検ガ
ス中に放置した場合と比べて小さくなった。本発明のセ
ンサは、炭酸ガスの分圧の変化に応じて炭酸水素イオン
の解離平衡が生じ、それによって二酸化炭素濃度を測定
していることがわかる。Further, with respect to the No. 1 to 3 sensors, after leaving them in a test gas having a CO 2 concentration of 350 ppm in dry air, the infrared absorption spectra of the solid electrolyte and the metal oxide layer of the sensor were measured. , HCO 3 - 1000 derived from the
The peak around cm −1 was smaller than that when left in the test gas having a CO 2 concentration of 10,000 ppm. It can be seen that the sensor of the present invention measures the carbon dioxide concentration by causing dissociation equilibrium of hydrogen carbonate ions in response to changes in the partial pressure of carbon dioxide.
【0117】<実施例8>さらに、本発明のセンサにつ
いて、吸着ガスを分析した。それぞれのセンサを乾燥空
気中、CO2濃度10000ppmの被検ガス中に放置した
後、ANELVA社製質量分析装置 AGS-211R を用いて、TD
S法(Thermal Desorption Spectroscopy : 真空加熱抽
出・質量分析法)により、加熱しながら、質量数18
(H2O)および質量数44(CO2)の電流変化値をモ
ニターした。<Example 8> Further, the adsorbed gas was analyzed for the sensor of the present invention. After each sensor was left in dry air in a test gas with a CO 2 concentration of 10,000 ppm, TD was performed using an ANELVA mass spectrometer AGS-211R.
While heating by S method (Thermal Desorption Spectroscopy: vacuum heating extraction / mass spectrometry), mass number 18
The current change values of (H 2 O) and mass number 44 (CO 2 ) were monitored.
【0118】その結果、すべてのセンサで、50〜30
0℃でH2O(質量数18)、CO2(質量数44)のピ
ークが同時に検出された。このことからも炭酸水素イオ
ン(HCO3 -)が吸着していることが示唆される。As a result, all the sensors have 50 to 30
At 0 ° C., H 2 O (mass number 18) and CO 2 (mass number 44) peaks were simultaneously detected. This also suggests that hydrogen carbonate ions (HCO 3 − ) are adsorbed.
【0119】[0119]
【発明の効果】以上のように、本発明によれば、室温で
作動し、十分な感度と応答性が得られ、選択性が高く、
耐湿性にも優れた二酸化炭素センサと、この二酸化炭素
センサを用いた二酸化炭素濃度の測定方法とを提供でき
る。As described above, according to the present invention, it is possible to operate at room temperature, obtain sufficient sensitivity and responsiveness, and have high selectivity.
It is possible to provide a carbon dioxide sensor having excellent moisture resistance and a method for measuring carbon dioxide concentration using the carbon dioxide sensor.
【図1】本発明の分離型二酸化炭素センサの構成例を示
す断面図である。FIG. 1 is a cross-sectional view showing a configuration example of a separation type carbon dioxide sensor of the present invention.
【図2】本発明の非分離型二酸化炭素センサの構成例を
示す断面図である。FIG. 2 is a cross-sectional view showing a configuration example of a non-separable carbon dioxide sensor of the present invention.
【図3】検知極がIn2O3とNaHCO3とAuメッシ
ュとから成り、対極がPtメッシュである本発明の分離
型二酸化炭素センサと、検知極がPbOとAuメッシュ
とから成り、対極がPtメッシュである比較例の分離型
二酸化炭素センサの、CO2濃度に対する出力起電力値
の特性図である。FIG. 3 shows a separation type carbon dioxide sensor of the present invention in which the detection electrode is made of In 2 O 3 , NaHCO 3 and Au mesh and the counter electrode is Pt mesh, and the detection electrode is made of PbO and Au mesh, and the counter electrode is It is a characteristic view of the output electromotive force value with respect to the CO 2 concentration of the separation type carbon dioxide sensor which is a Pt mesh.
【図4】検知極がIn2O3とNaHCO3とAuメッシ
ュとから成り、対極がPtメッシュである本発明の分離
型二酸化炭素センサの、相対湿度80%雰囲気下24時
間保管後の基準ガス(CO2濃度1000ppm)中の起電
力値の時間変化である。FIG. 4 is a reference gas of the separation-type carbon dioxide sensor of the present invention in which the detection electrode is made of In 2 O 3 , NaHCO 3, and Au mesh and the counter electrode is Pt mesh after being stored for 24 hours in an atmosphere of relative humidity of 80%. It is a change with time of an electromotive force value in (CO 2 concentration 1000 ppm).
【図5】検知極がIn2O3とWO3とAuメッシュとか
ら成り、対極がIn2O3粉末電極である本発明の非分離
型二酸化炭素センサの、相対湿度80%雰囲気下24時
間保管後の基準ガス(CO2濃度1000ppm)中の起電
力値の時間変化である。FIG. 5 is a non-separable carbon dioxide sensor of the present invention in which the detection electrode is made of In 2 O 3 , WO 3 and Au mesh, and the counter electrode is an In 2 O 3 powder electrode, in an atmosphere of 80% relative humidity for 24 hours. It is a change with time of the electromotive force value in the reference gas (CO 2 concentration 1000 ppm) after storage.
【図6】検知極がNa2CO3とAuメッシュとから成
り、対極がPtメッシュである比較例の分離型二酸化炭
素センサの、相対湿度80%雰囲気下24時間保管後の
基準ガス(CO2濃度1000ppm)中の起電力値の時間
変化である。FIG. 6 is a reference gas (CO 2 of a separation type carbon dioxide sensor of Comparative Example in which the detection electrode is composed of Na 2 CO 3 and Au mesh and the counter electrode is Pt mesh, after being stored for 24 hours in an atmosphere with relative humidity of 80%. It is a change with time of the electromotive force value in a concentration of 1000 ppm).
1 二酸化炭素センサ 2 固体電解質 3 検知極 4 金属酸化物層 5 集電体 6 対極 1 carbon dioxide sensor 2 Solid electrolyte 3 detection poles 4 Metal oxide layer 5 Current collector 6 opposite poles
フロントページの続き (56)参考文献 特開2000−88799(JP,A) 特開2000−88797(JP,A) 特開 平11−271270(JP,A) 特開 平1−267453(JP,A) 特開 平3−21860(JP,A) 特公 平4−79542(JP,B2) (58)調査した分野(Int.Cl.7,DB名) G01N 27/416 G01N 27/406 Continuation of the front page (56) Reference JP 2000-88799 (JP, A) JP 2000-88797 (JP, A) JP 11-271270 (JP, A) JP 1-267453 (JP, A) ) JP-A-3-21860 (JP, A) JP-B-4-79542 (JP, B2) (58) Fields investigated (Int.Cl. 7 , DB name) G01N 27/416 G01N 27/406
Claims (17)
接して設けられており、 前記固体電解質が金属イオン導電体を含有し、 前記検知極が、金属酸化物を含有する金属酸化物層と、
集電体とを有し、 前記検知極が、少なくとも二酸化炭素存在下で、炭酸水
素イオンを含有する二酸化炭素センサ。1. A detection electrode and a counter electrode are respectively provided in contact with a solid electrolyte, the solid electrolyte contains a metal ion conductor, and the detection electrode has a metal oxide layer containing a metal oxide. ,
A carbon dioxide sensor having a current collector, wherein the detection electrode contains hydrogen carbonate ions in the presence of at least carbon dioxide.
接して設けられており、 前記固体電解質が金属イオン導電体を含有し、 前記検知極が、金属酸化物を含有する金属酸化物層と、
集電体とを有し、 前記金属酸化物層が金属炭酸水素塩を含有する二酸化炭
素センサ。2. A detection electrode and a counter electrode are respectively provided in contact with a solid electrolyte, the solid electrolyte contains a metal ion conductor, and the detection electrode has a metal oxide layer containing a metal oxide. ,
A carbon dioxide sensor having a current collector, wherein the metal oxide layer contains a metal hydrogen carbonate.
び/または金属炭酸塩を含有する請求項1または2の二
酸化炭素センサ。3. The carbon dioxide sensor according to claim 1, wherein the metal oxide layer contains a metal hydrogen carbonate and / or a metal carbonate.
ム、炭酸水素ナトリウム、炭酸水素カリウム、炭酸水素
ルビジウム、炭酸水素セシウム、炭酸水素マグネシウム
および炭酸水素カルシウムのいずれか一種以上を含有す
る請求項2または3の二酸化炭素センサ。4. The metal oxide layer contains at least one of lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, magnesium hydrogen carbonate and calcium hydrogen carbonate. Or 3 carbon dioxide sensor.
よび/または金属炭酸塩を前記金属酸化物に対して1〜
99wt%含有する請求項2〜4のいずれかの二酸化炭素
センサ。5. The metal oxide layer comprises metal hydrogen carbonate and / or metal carbonate in an amount of 1 to 3 with respect to the metal oxide.
The carbon dioxide sensor according to any one of claims 2 to 4, which contains 99 wt%.
酸化スズ、酸化コバルト、酸化タングステン、酸化亜
鉛、酸化鉛、酸化銅、酸化鉄、酸化ニッケル、酸化クロ
ム、酸化カドミウム、酸化ビスマス、酸化マンガン、酸
化イットリウム、酸化アンチモン、酸化ランタン、酸化
セリウム、酸化プラセオジム、酸化ネオジム、酸化銀、
酸化リチウム、酸化ナトリウム、酸化カリウム、酸化ル
ビジウム、酸化セシウム、酸化マグネシウム、酸化カル
シウム、酸化ストロンチウムおよび酸化バリウムのいず
れか一種以上を含有する請求項1〜5のいずれかの二酸
化炭素センサ。6. The metal oxide layer is indium oxide,
Tin oxide, cobalt oxide, tungsten oxide, zinc oxide, lead oxide, copper oxide, iron oxide, nickel oxide, chromium oxide, cadmium oxide, bismuth oxide, manganese oxide, yttrium oxide, antimony oxide, lanthanum oxide, cerium oxide, praseodymium oxide , Neodymium oxide, silver oxide,
6. The carbon dioxide sensor according to claim 1, which contains one or more of lithium oxide, sodium oxide, potassium oxide, rubidium oxide, cesium oxide, magnesium oxide, calcium oxide, strontium oxide and barium oxide.
1〜6のいずれかの二酸化炭素センサ。7. The carbon dioxide sensor according to claim 1, wherein the metal oxide layer is porous.
表面に存在する請求項1、3、4、5、6または7のい
ずれかの二酸化炭素センサ。8. The carbon dioxide sensor according to claim 1, wherein the hydrogen carbonate ions are present on the surface of the metal oxide layer.
面に存在する請求項1、3、4、5、6または7のいず
れかの二酸化炭素センサ。9. The carbon dioxide sensor according to claim 1, wherein the hydrogen carbonate ions are present on the surface of the solid electrolyte.
金属酸化物層に侵入している請求項1〜9のいずれかの
二酸化炭素センサ。10. The carbon dioxide sensor according to claim 1, wherein mobile ionic species of the solid electrolyte penetrate into the metal oxide layer.
1〜10のいずれかの二酸化炭素センサ。11. The carbon dioxide sensor according to claim 1, wherein the current collector is a porous metal.
で固体電解質に対向して設けられている請求項1〜11
のいずれかの二酸化炭素センサ。12. The current collector is provided so as to face the solid electrolyte with the metal oxide layer interposed therebetween.
Carbon dioxide sensor of either.
解質の同一の面上に設けられている請求項1〜12のい
ずれかの二酸化炭素センサ。13. The carbon dioxide sensor according to claim 1, wherein the detection electrode and the counter electrode are provided on the same surface of the solid electrolyte.
ずれか一種以上を含有する請求項1〜13のいずれかの
二酸化炭素センサ。14. The carbon dioxide sensor according to claim 1, wherein the counter electrode contains at least one of a metal and a metal oxide.
素センサを用い、 二酸化炭素が炭酸水素イオンの形で前記検知極に吸着し
て二酸化炭素濃度が測定される二酸化炭素濃度の測定方
法。15. A method for measuring a carbon dioxide concentration using the carbon dioxide sensor according to claim 1, wherein carbon dioxide is adsorbed to the detection electrode in the form of hydrogen carbonate ion to measure the carbon dioxide concentration.
表面に吸着する請求項15の二酸化炭素濃度の測定方
法。16. The method for measuring carbon dioxide concentration according to claim 15, wherein the hydrogen carbonate ions are adsorbed on the surface of the metal oxide.
表面に吸着する請求項15の二酸化炭素濃度の測定方
法。17. The method for measuring carbon dioxide concentration according to claim 15, wherein the hydrogen carbonate ions are adsorbed on the surface of the solid electrolyte.
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| KR100434985B1 (en) * | 2001-06-22 | 2004-06-07 | 한라산업개발 주식회사 | Solid Electrolyte Carbon Dioxide Gas Sensor Having Oxides as Reference Electrode and Fabricating Method thereof |
| US7006926B2 (en) | 2003-02-07 | 2006-02-28 | Tdk Corporation | Carbon dioxide sensor |
| JP2006162243A (en) * | 2004-11-10 | 2006-06-22 | Osaka Gas Co Ltd | Gaseous hydrogen removing device |
| JP4627671B2 (en) * | 2005-03-22 | 2011-02-09 | フィガロ技研株式会社 | CO2 sensor |
| DE102005059594A1 (en) * | 2005-12-14 | 2007-06-21 | Robert Bosch Gmbh | Sensor element and method and means for its production |
| JP5019441B2 (en) * | 2007-04-04 | 2012-09-05 | 独立行政法人産業技術総合研究所 | Organic antimony compound, method for producing the same, and sensor using the same |
| JP6325843B2 (en) * | 2014-03-06 | 2018-05-16 | 矢崎エナジーシステム株式会社 | Potential detection type solid electrolyte oxygen sensor |
| CN114136853B (en) * | 2021-11-25 | 2024-09-06 | 西安交通大学 | A sensor and method for detecting the concentration of active metal oxides in air |
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