CN105692690A - Preparation method of stannic oxide gas sensitive material - Google Patents

Abstract

The invention discloses a preparation method of a tin dioxide gas-sensitive material, specifically: heating and calcining tin dioxide powder, and then cooling to obtain the tin dioxide gas-sensitive material. The invention uses commercially available tin dioxide powder as a raw material, adopts the method of calcination and low-temperature quenching to regulate the concentration of oxygen vacancies in the material, and further regulates the gas-sensing performance of the material. The invention has the advantages of low cost, simple method and good repeatability for preparing the tin dioxide gas-sensitive material, and the obtained tin dioxide gas-sensitive material has good gas-sensing performance, which is favorable for popularization and application in production and life.

Description

A kind of preparation method of tin dioxide gas sensitive material

technical field

The invention belongs to the field of gas-sensitive material preparation and relates to a preparation method of tin dioxide gas-sensitive material.

Background technique

Tin dioxide is a very important semiconductor material, because of its good selectivity and stability, as well as non-toxic and cheap properties, it has achieved important applications in gas sensors. Although researchers have conducted extensive research on tin dioxide gas-sensing materials, there are still some problems. Among them, high response temperature, long response time, and cumbersome preparation methods are still the bottlenecks. At present, the modification methods reported in the literature mainly include morphology control and composition doping.

The document "CJDong, X.Liu, XCXiao, G.Chen, YDWang, I.Djerdj, Combustionsynthesis of porous Pt-functionalized SnO ₂ sheets for isopropanol gas detection with a significant tenhancement in response, J. Mater. Chem. A2 (2014) 20089-20095" reported a method of preparation. The specific surface area of the material is increased by the preparation of tin dioxide nanosheets, and the comprehensive sensitivity performance is improved by the doping of metal platinum, which is also the way most of the current literature explores. However, the preparation of nanosheets requires the introduction of additional surfactants, and platinum is an expensive noble metal. In addition, in some literatures, in order to control the morphology, methods such as ion sputtering and electrospinning are sometimes introduced, which are neither cheap nor convenient, and the repeatability needs to be improved, so these methods are not suitable for large-scale promotion. .

Contents of the invention

The purpose of the present invention is to provide a method for preparing a tin dioxide gas-sensitive material, which solves the problems of tedious process, poor repeatability and high cost in the existing gas-sensitive material modification method.

The technical solution adopted in the present invention is a preparation method of a tin dioxide gas-sensitive material, specifically: heating and calcining tin dioxide powder, and then cooling to obtain the tin dioxide gas-sensitive material.

The present invention is also characterized in that,

The heating and calcination specifically includes: heating the tin dioxide powder to 1000-1800° C., and keeping it warm for 8-20 hours.

The cooling method is natural cooling or low temperature quenching.

The low-temperature quenching specifically includes: first cooling the calcined tin dioxide powder to 800-1700° C., and then quenching in a low-temperature quenching medium.

The cryogenic quenching medium is liquid nitrogen.

The beneficial effect of the present invention is that the preparation method of a tin dioxide gas-sensitive material of the present invention uses commercially available tin dioxide powder as a raw material, adopts the method of calcination and low-temperature quenching to regulate the concentration of oxygen vacancies in the material, and then regulates the Gas-sensing properties of materials. The invention has the advantages of low cost, simple method and good repeatability for preparing the tin dioxide gas-sensitive material, and the obtained tin dioxide gas-sensitive material has good gas-sensitive performance, which is favorable for popularization and application in production and life.

Description of drawings

Fig. 1 is the XRD collection of illustrative plates of embodiment 1 gained sample;

Fig. 2 is the XPS collection of illustrative plates of the oxygen element in the obtained sample of four examples of the inventive method;

Fig. 3 is the sensitivity of the gas sensor made of the sample obtained in Example 4 at 300°C under different ethanol concentrations.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The invention provides a kind of preparation method of tin dioxide gas-sensitive material, specifically implement according to the following steps:

Step 1, heating commercially available tin dioxide powder to 1000-1800°C and keeping it warm for 8-20 hours;

In step 2, the powder obtained in step 1 is cooled to obtain a tin dioxide gas-sensitive material. The cooling methods include natural cooling and low-temperature quenching, wherein the low-temperature quenching medium is liquid nitrogen, and the quenching temperature is 800-1700°C (first cool the powder to 800-1700°C, and then quench in liquid nitrogen).

The invention uses commercially available tin dioxide powder as a raw material, adopts the method of calcination and low-temperature quenching to regulate the concentration of oxygen vacancies in the material, and further regulates the gas-sensing performance of the material. The invention has the advantages of low cost, simple method and good repeatability for preparing the tin dioxide gas-sensitive material, and the obtained tin dioxide gas-sensitive material has good gas-sensitive performance, which is favorable for popularization and application in production and life.

Example 1

Step 1, heating 1g of commercially available tin dioxide powder to 1000°C and keeping it warm for 8h;

In step 2, the sample is naturally cooled to room temperature in a furnace to obtain a tin dioxide gas-sensitive material.

Figure 1 is the XRD spectrum of the obtained sample. It can be seen from the figure that there are obvious diffraction peaks at 2θ values of 26.6°, 33.9°, 39.0° and 51.8°, combined with other weaker peaks, corresponding to The rutile tin dioxide indicates that the tin dioxide gas-sensing material prepared in this example does not change the phase structure of the tin dioxide.

Example 2

Step 1, heating 2g of commercially available tin dioxide powder to 1200°C and keeping it warm for 10h;

Step 2, the sample is cooled to 800°C in a furnace, and then quenched in liquid nitrogen to obtain a tin dioxide gas-sensitive material.

Example 3

Step 1, heating 4g of commercially available tin dioxide powder to 1500°C and keeping it warm for 12h;

In step 2, the sample is cooled to 1300°C in a furnace, and then quenched in liquid nitrogen to obtain a tin dioxide gas-sensitive material.

Example 4

Step 1, heating 5g of commercially available tin dioxide powder to 1800°C and keeping it warm for 20h;

In step 2, the sample is cooled to 1700°C in a furnace, and then quenched in liquid nitrogen to obtain a tin dioxide gas-sensitive material.

Fig. 2 is the XPS spectrum of the oxygen element in the sample obtained in four examples. It can be seen from the figure that in the XPS spectra of O elements in all samples, the peaks corresponding to O can be fitted into two sub-peaks at 530.2 and 531.5eV, which correspond to the O atoms in SnO ₂ and the grain surface of oxygen vacancies. It is proved that there are oxygen vacancies in all the samples. The relative concentration of the two oxygen components can be estimated by calculating the area enclosed by the curve and the abscissa. It was found that the higher the quenching temperature, the higher the concentration of oxygen vacancies.

Fig. 3 is the sensitivity of the gas sensor made of the sample obtained in Example 4 at 300°C under different ethanol concentrations. It can be seen that with the increase of acetic acid concentration, its sensitivity shows an increasing trend.

Claims (5)

1. the preparation method of a tin dioxide gas-sensitive material, it is characterised in that by tin ash powder heating and calcining, then cool down, namely obtain tin dioxide gas-sensitive material。

2. the preparation method of a kind of tin dioxide gas-sensitive material according to claim 1, it is characterised in that described heating and calcining, particularly as follows: heat tin ash powder to 1000～1800 DEG C, is incubated 8～20h。

3. the preparation method of a kind of tin dioxide gas-sensitive material according to claim 1, it is characterised in that the described type of cooling is natural cooling or low temperature quenching。

4. the preparation method of a kind of tin dioxide gas-sensitive material according to claim 3, it is characterised in that described low temperature quenching, particularly as follows: first the tin ash powder after calcining is cooled to 800～1700 DEG C, then quenches in low temperature quenching medium。

5. the preparation method of a kind of tin dioxide gas-sensitive material according to claim 4, it is characterised in that described low temperature quenching medium is liquid nitrogen。