Preparation method of doped modified stannic oxide nano material for gas sensitive sensor and product and application of doped modified stannic oxide nano material

Abstract

The invention discloses a preparation method of a doped modified tin dioxide nano material for a gas sensitive sensor as well as a product and application of the doped modified tin dioxide nano material. According to the method provided by the invention, the stability, the sensitivity to gas and the response time of tin oxide can be greatly improved, and the method is simple in preparation process, so that a metal oxide system material has a wider application prospect in the field of gas sensitive sensors.

Description

Technical Field

[0001] The present invention relates to the technical field of gas sensors, and in particular to a preparation method of a doped and modified tin dioxide nanomaterial for a gas sensor, and a product and application thereof. Background Art

[0002] SnO2 has always attracted the attention of the scientific research and industry as a gas-sensitive material, but the conductivity of semiconductor metal oxides is poor. By combining with carbon materials, its conductivity can be improved, thereby improving the gas sensitivity of the material. A large number of research results show that the gas-sensitive performance of the material can be improved through processes such as metal oxide surface modification and metal / precious metal doping, and it has a very wide range of applications in the field of gas sensors.

[0003] The present invention creatively increases the active sites of the system through low-temperature treatment and high-temperature reaction, improves the stability of the material, accelerates the adsorption and reaction characteristics of the gas, greatly improves the reaction activity and response time of the material, and thus can improve the sensitivity, response time and selectivity of the gas-sensitive material, which has practical application value for further promoting the development of semiconductor gas-sensitive devices. Summary of the invention

[0004] The present invention aims to provide a method for preparing a doped modified tin dioxide nanomaterial for a gas sensor.

[0005] Another object of the present invention is to provide a doped and modified tin dioxide nanomaterial product for a gas sensor prepared by the above method.

[0006] Another object of the present invention is to provide an application of the above product.

[0007] The object of the present invention is achieved by the following scheme: A method for preparing a doped modified tin dioxide nanomaterial for a gas sensor, using a hydrothermal method to prepare a zinc oxide nanomaterial as a carrier, and then performing surface modification, comprising the following steps: Step 1: Take tin tetrachloride, sodium hydroxide and cerium chloride in a molar ratio of 1:2:0.01~1:5:0.02, add a certain amount of distilled water, stir, and obtain solution A; Step 2: placing the above solution in a reactor and reacting at 100-300°C for 3-7 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, and placing the obtained powder in a muffle furnace and calcining at 300-500°C for 1-3 hours to obtain a modified tin oxide nanopowder; Step 3: Weigh the modified tin oxide nanopowder, place it in a certain amount of ethanol, and stir until it is completely dissolved. Add (CH3COO)2Cu ethanol solution at a mass ratio of 1-10% of zinc oxide, stir well to mix it evenly. Heat it at 100-300 °C for 1-5 hours, wash it, and dry it to obtain the doped modified tin oxide nanomaterial.

[0008] The prepared powder was dispersed and coated on a six-pin ceramic tube gas-sensitive test element, placed on an aging table for one week, and tested for its response to methanol gas using a WS-30A gas-sensitive element test system at a test temperature of 200 °C. The aging table was placed in a sealed container, and methanol was injected to a concentration of 20 ppm to test its response to methanol gas.

[0009] A simple and feasible method for preparing doped modified SnO2 nanomaterials, using a hydrothermal method to prepare zinc oxide nanomaterials as a carrier, and then performing surface modification. The method provided by the invention can greatly improve the stability of zinc oxide, its sensitivity to gas and its response time. The method has a simple preparation process, which makes the metal oxide system materials have a broader application prospect in the field of gas sensors. DETAILED DESCRIPTION

[0010] The embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments. Example 1

[0011] A doped modified tin dioxide nanomaterial for a gas sensor is prepared by using a hydrothermal method to prepare a zinc oxide nanomaterial as a carrier, and then surface modification is performed in the following steps: Step 1: Take 1.361 g of tin tetrachloride, 2.73 g of sodium hydroxide and 0.0032 g of cerium chloride, add them into 80 ml of distilled water, and stir for 30 minutes to obtain solution A; Step 2: placing the above solution A in a hydrothermal reactor and reacting at 180°C for 3 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, and calcining the obtained powder in a muffle furnace at 500°C for 1 hour to obtain a modified tin oxide nanopowder; Step 3: Place 0.5 g of modified tin oxide nanopowder in 30 ml of ethanol and stir with a magnetic stirrer until completely dissolved; add 0.05 g of (CH3COO)2Cu ethanol solution and stir thoroughly to mix evenly; perform hydrothermal reaction at 100°C for 5 hours, wash and dry to obtain doped modified tin oxide nanomaterial powder.

[0012] The powder prepared in this embodiment was dispersed and coated on a six-pin ceramic tube gas sensor test element. The response to methanol gas at different concentrations was tested using a WS-30A gas sensor test system. The working temperature was 200° C., and the sensitivity to 20 ppm methanol gas reached 28.9. Example 2

[0013] A doped and modified tin dioxide nanomaterial for a gas sensor is prepared in the following steps, similar to the steps in the embodiment: Step 1: Take 2.513 g of tin tetrachloride, 1.921 g of sodium hydroxide and 0.0041 g of cerium chloride, add them into 100 ml of distilled water, and stir for 30 minutes to obtain solution A; Step 2: placing the above solution A in a hydrothermal reactor and reacting at 200°C for 6 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, and placing the obtained powder in a muffle furnace and calcining at 450°C for 2 hours to obtain a modified tin oxide nanopowder; Step 3: Place 1 g of modified tin oxide nanopowder in 40 ml of ethanol and stir with a magnetic stirrer until completely dissolved; add 0.04 g of (CH3COO)2Cu ethanol solution and stir thoroughly to mix evenly; perform hydrothermal reaction at 150°C for 4 hours, wash and dry to obtain doped modified tin oxide nanomaterial powder.

[0014] The powder prepared in this embodiment was dispersed and coated on a six-pin ceramic tube gas sensor test element. The response to methanol gas at different concentrations was tested using a WS-30A gas sensor test system. The working temperature was 200° C., and the sensitivity to 20 ppm methanol gas reached 27.8. Example 3

[0015] A doped and modified tin dioxide nanomaterial for a gas sensor is prepared in the following steps, similar to the steps in the embodiment: Step 1: Take 22.605 g of tin tetrachloride, 2.74 g of sodium hydroxide and 0.005 g of cerium chloride, add them into 50 ml of distilled water, and stir for 30 minutes to obtain solution A; Step 2: placing the above solution A in a hydrothermal reactor and reacting at 300°C for 4 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, and placing the obtained powder in a muffle furnace and calcining at 400°C for 2 hours to obtain a modified tin oxide nanopowder; Step 3: Place 0.5 g of modified tin oxide nanopowder in 50 ml of ethanol and stir with a magnetic stirrer until completely dissolved; add 0.005 g of (CH3COO)2Cu ethanol solution and stir thoroughly to mix evenly; perform hydrothermal reaction at 100°C for 3 hours, wash and dry to obtain doped modified tin oxide nanomaterial powder.

[0016] The powder prepared in this embodiment was dispersed and coated on a six-pin ceramic tube gas sensor test element. The response to methanol gas at different concentrations was tested using a WS-30A gas sensor test system. The working temperature was 200° C., and the sensitivity to 20 ppm methanol gas reached 26.7.

Claims

1. A method for preparing a doped modified tin dioxide nanomaterial for a gas sensor, characterized in that The zinc oxide nanomaterial is prepared by hydrothermal method as a carrier, and then surface modified, including the following steps: Step 1: Take tin tetrachloride, sodium hydroxide and cerium chloride in a molar ratio of 1:2:0.01-1:5:0.02, add distilled water, stir, and obtain solution A; Step 2: placing the above solution A in a reactor and reacting at 100-300°C for 3-7 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, placing the obtained powder in a muffle furnace and calcining at 300-500°C for 1-3 hours to obtain a modified tin oxide nanopowder; Step 3: Place the modified tin oxide nanopowder in ethanol and stir until completely dissolved. Add (CH3COO)2Cu ethanol solution at a mass ratio of 1-10% of tin oxide and stir thoroughly to mix evenly; hydroheat at 100-300 °C for 1-5 hours, wash and dry to obtain the doped modified tin oxide nanomaterial.

2. The method for preparing the doped modified tin dioxide nanomaterial for gas sensor according to claim 1, characterized in that: Prepare as follows: Step 1: Take 1.361 g of tin tetrachloride, 2.73 g of sodium hydroxide and 0.0032 g of cerium chloride, add them into 80 ml of distilled water, and stir for 30 minutes to obtain solution A; Step 2: placing the above solution A in a hydrothermal reactor and reacting at 180°C for 3 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, and calcining the obtained powder in a muffle furnace at 500°C for 1 hour to obtain a modified tin oxide nanopowder; Step 3: Place 0.5 g of modified tin oxide nanopowder in 30 ml of ethanol and stir with a magnetic stirrer until completely dissolved; add 0.05 g of (CH3COO)2Cu ethanol solution and stir thoroughly to mix evenly; perform hydrothermal reaction at 100°C for 5 hours, wash and dry to obtain doped modified tin oxide nanomaterial powder.

3. The method for preparing the doped modified tin dioxide nanomaterial for gas sensor according to claim 1, characterized in that: Prepared as follows: Step 1: Take 2.513 g of tin tetrachloride, 1.921 g of sodium hydroxide and 0.0041 g of cerium chloride, add them into 100 ml of distilled water, and stir for 30 minutes to obtain solution A; Step 2: placing the above solution A in a hydrothermal reactor and reacting at 200°C for 6 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, and placing the obtained powder in a muffle furnace and calcining at 450°C for 2 hours to obtain a modified tin oxide nanopowder; Step 3: Place 1 g of modified tin oxide nanopowder in 40 ml of ethanol and stir with a magnetic stirrer until completely dissolved; add 0.04 g of (CH3COO)2Cu ethanol solution and stir thoroughly to mix evenly; perform hydrothermal reaction at 150°C for 4 hours, wash and dry to obtain doped modified tin oxide nanomaterial powder.

4. The method for preparing the doped modified tin dioxide nanomaterial for gas sensor according to claim 1, characterized in that: Prepared as follows: Step 1: Take 22.605 g of tin tetrachloride, 2.74 g of sodium hydroxide and 0.005 g of cerium chloride, add them into 50 ml of distilled water, and stir for 30 minutes to obtain solution A; Step 2: placing the above solution A in a hydrothermal reactor and reacting at 300°C for 4 hours; when the temperature drops to room temperature, centrifuging and drying the sample to obtain a powder, and placing the obtained powder in a muffle furnace and calcining at 400°C for 2 hours to obtain a modified tin oxide nanopowder; Step 3: Place 0.5 g of modified tin oxide nanopowder in 50 ml of ethanol and stir with a magnetic stirrer until completely dissolved; add 0.005 g of (CH3COO)2Cu ethanol solution and stir thoroughly to mix evenly; perform hydrothermal reaction at 100°C for 3 hours, wash and dry to obtain doped modified tin oxide nanomaterial powder.

5. A doped modified tin dioxide nanomaterial for gas sensor, characterized in that Prepared according to the method according to any one of claims 1 to 4.

6. Use of the doped modified tin dioxide nanomaterial according to claim 5 in a gas sensor for detecting methanol gas.