Method for improving stability of hydrogen sulfide-sensitive tin dioxide gas sensor material

A gas-sensing material, tin dioxide technology, applied in the field of gas-sensing sensors, can solve problems such as poor stability

Active Publication Date: 2018-03-23
SHANGHAI NAT ENG RES CENT FORNANOTECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] For SnO 2 The gas sensitive material detects H 2 The problem of poor stability in the S gas process, the purpose of the present invention is to provide a simple and feasible method for improving the stability of the hydrogen sulfide sensitive tin dioxide gas sensitive material

Method used

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  • Method for improving stability of hydrogen sulfide-sensitive tin dioxide gas sensor material

Examples

Experimental program
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Effect test

Embodiment 1

[0018] commercial SnO 2 Nanomaterials are sensitive materials. Prepare 200mL of sodium thiosulfate aqueous solution with a concentration of 0.1mol / L, add appropriate amount of SnCl 4 ·5H 2 O, weighed SnO 2 The powder is placed in the above solution, sodium thiosulfate: SnCl 4 ·5H 2 O: SnO 2 The molar ratio is 3:1:30, stir for 3 hours, add 20 mL of tartaric acid; place in a reaction kettle, react at 120 °C for 3.5 hours; wait until the temperature drops to room temperature, centrifuge and dry the sample;

[0019] Put the above sample precursor and urea into a high-energy ball mill, the mass ratio of precursor to urea is 3:1, ball mill at 350 r / min in Ar atmosphere for 8 hours, and then put it in a muffle furnace for 5 hours at 450 °C. , to obtain the surface porous SnSO4-modified SnO 2 Nano powder.

[0020] figure 1 is a commercial SnO 2 With the sample treated in this example, the H of 10 ppm 2 Sensitivity comparison chart of S gas, the working temperature is 230 ℃,...

Embodiment 2

[0022] commercial SnO 2 Nanomaterials are sensitive materials. Mix 200mL of sodium thiosulfate aqueous solution with a concentration of 0.3mol / L, add appropriate amount of SnCl 4 ·5H 2 O, weighed SnO 2 The powder is placed in the above solution, sodium thiosulfate: SnCl 4 ·5H 2 O: SnO 2 The molar ratio was 2:1:30, stirred for 3 hours, and 30 mL of malic acid was added; placed in a reaction kettle, reacted at 120 °C for 5 hours; when the temperature dropped to room temperature, the sample was centrifuged and dried.

[0023] Put the above sample precursor and urea into a high-energy ball mill, the mass ratio of the precursor to urea is 5:1, ball mill at 300 r / min for 10 hours in an Ar atmosphere, and then put it into a muffle furnace for calcination at 350 °C for 6 hours , to obtain the surface porous SnSO4-modified SnO 2 Nano powder.

[0024] This embodiment and embodiment 1 adopt the same commercial SnO 2 , the treated sample reacts to 10 ppm H 2 S gas sensitivity in...

Embodiment 3

[0026] SnO synthesized by hydrothermal method 2 Nanomaterials are sensitive materials. Prepare 200mL of sodium sulfite aqueous solution with a concentration of 0.2mol / L, add appropriate amount of SnCl 4 ·5H 2 O, weighed SnO 2 The powder is placed in the above solution, sodium sulfite: SnCl 4 ·5H 2 O: SnO 2 The molar ratio was 2:1:40, stirred for 3 hours, added 60 mL of citric acid; placed in a reaction kettle, reacted for 3 hours at 180 ° C; when the temperature dropped to room temperature, the sample was centrifuged and dried;

[0027] Put the above sample precursor and urea into a high-energy ball mill with a mass ratio of precursor to urea of ​​5:1, ball mill for 2 hours at 500 r / min in an Ar atmosphere, and then put it into a muffle furnace for calcination at 350 °C for 6 hours , to obtain the surface porous SnSO4-modified SnO 2 Nano powder.

[0028] SnO directly synthesized by hydrothermal method 2 powder to 10 ppm H 2 S gas sensitivity at 73.2, at H 2 After be...

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Abstract

The invention discloses a method for improving the stability of a hydrogen sulfide-sensitive SnO2 gas sensor material. The method comprises the following steps: preparing an aqueous solution of a sulfur salt and SnCl4.5H2O, placing the SnO2 gas sensor material in the above solution, performing stirring, and adding an appropriate amount of a complexing agent; placing the above obtained solution ina reactor, and performing a reaction for 3-5 h; cooling the reactor to room temperature, and centrifuging and drying the obtained sample; and placing the obtained powder precursor in a high-energy ball mill, performing ball milling, placing the ball-milled powder precursor in a muffle furnace, and performing calcination to obtain a tin sulfate- modified SnO2 nano-powder with a porous surface. Themethod, aiming at the problem of poor stability of the SnO2 gas sensor material in the H2S gas detection process, uses the sulfur salt to preprocess the gas sensor material to form a porous sulfate film on the surface of SnO2 in order to effectively prevent the SnO2 from reacting with sulfide during use, it is expected to ensure the long-term stability of the sensor in the H2S gas atmosphere. Themethod has the advantages of simple preparation process, realization of mass production, realization of stable performances, and broad application prospect.

Description

technical field [0001] The invention relates to the technical field of gas sensors, in particular to a method for improving the stability of nanomaterials, in particular to a method for improving the sensitivity of hydrogen sulfide to tin dioxide (SnO 2 ) method for the stability of gas-sensitive materials. Background technique [0002] SnO 2 Due to the advantages of excellent performance, environmental friendliness, abundant resources, and low price, as a gas-sensing material, it has the advantages of fast response / recovery time and high sensitivity, and has a very wide range of applications in the field of gas-sensing sensors. Although the sensor with SnO2 as the sensitive material has high sensitivity to H2S gas, long-term exposure to the gas atmosphere will easily lead to a decrease in the sensitivity of the sensitive material or even inactivation. How to improve the long-term stability of the gas-sensitive material is to further promote the use of SnO2 in the sensor. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N33/00C01G19/02B82Y30/00
CPCB82Y30/00C01G19/02G01N33/0044
Inventor 何丹农葛美英尹桂林孙健武张芳金彩虹
Owner SHANGHAI NAT ENG RES CENT FORNANOTECH
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