Preparation method of nano composite iron oxide material for gas sensor as well as product and application of nano composite iron oxide material
By preparing nanocomposite iron oxide materials and combining long-chain alkylamines and copper oxides, the problem of poor conductivity of semiconductor metal oxide gas-sensitive materials is solved, significantly improving the gas-sensitive performance and response speed, and expanding its application potential in the field of gas-sensitive sensors.
Patent Information
- Application Number
- CN202411974530.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-03-28
AI Technical Summary
The conductive properties of semiconductor metal oxide gas-sensitive materials are poor, which affects their gas sensitivity and response speed.
By reacting long-chain alkyl amine with iron chloride and sodium hydroxide at a specific molar ratio, a nanocomposite iron oxide material is generated, and the conductive and gas-sensitive properties of the material are improved by combining it with substances such as copper oxide and sodium dodecylbenzenesulfonate.
It significantly improves the gas-sensitive performance of nanocomposite iron oxide materials, enhances the sensitivity and response speed to methanol and acetone gases, and improves the stability and application prospects of the material.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of gas sensors, and in particular to a preparation method of a nano composite iron oxide material for a gas sensor, and a product and application thereof. Background Art
[0002] Metal oxides such as Fe2O3, ZnO, SnO2, WO3, etc. are widely studied gas-sensitive materials due to their excellent performance, environmental friendliness, abundant resources, and low price. The gas-sensitive properties of materials can be improved through processes such as metal oxide surface modification and metal / precious metal doping, and they are widely used in the field of gas sensors.
[0003] The key factors that determine the sensitivity of semiconductor gas-sensitive materials include the reaction between the material surface and the gas to be measured and the conductivity of the material. The former determines the response sensitivity of the sensitive material, and the latter determines the energy consumption of the material. Fe2O3 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. Summary of the invention
[0004] The present invention aims to provide a method for preparing a nano-composite iron oxide material for a gas sensor.
[0005] Another object of the present invention is to provide a nano-composite iron oxide material product for gas sensors 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 nanocomposite iron oxide material for a gas sensor comprises the following steps: (1) Dissolve the long-chain alkylamine in an alcohol solution to a concentration of 5-100 g / L, labeled as solution A; (2) Dissolve ferric chloride and sodium hydroxide in deionized water respectively to a molar ratio of 1:3-1:5, marked as B; (3) Slowly add B dropwise to solution A, react at normal pressure and low temperature of 0-40 °C for 2-30 h, centrifuge the product, wash it with alcohol solution 3-5 times, and dry it in an oven at 60-80 °C to obtain product C; (4) Dissolve 0.005-0.01 mol of copper oxide in deionized water, stir for 10-20 min, and then add 5-10 mL of aqueous ammonia to obtain solution D. Dissolve 5-10 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E. Add solution E dropwise into solution D and stir for 5-10 h to obtain solution F. Add product C to solution F to obtain solution G; 2-5 mmol of reducing agent was added dropwise to solution G and stirring was continued for 3-6 h. The obtained precipitate was washed several times with deionized water and ethanol, and then filtered and dried to obtain the final product.
[0008] The long-chain alkylamine described in the above preparation method is one of decaamine and dodecylamine or a combination thereof.
[0009] The alcohol described in the above preparation method is one or a combination of methanol, ethanol or propanol.
[0010] The reducing agent described in the above preparation method is ascorbic acid or sodium borohydride or a combination thereof.
[0011] The present invention provides a nano composite iron oxide material for a gas sensor, which is characterized in that it is prepared according to any of the above methods.
[0012] The invention provides an application of a nano composite iron oxide material in a gas sensor for methanol gas.
[0013] 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 180°C. The aging table was placed in a sealed container, methanol was injected to a concentration of 1ppm, and its response to acetone gas was tested.
[0014] The present invention provides a simple method for preparing nanocomposite iron oxide materials, which can increase the specific surface area and active sites of the material surface, greatly improve the gas sensing performance of the nanomaterial, and the preparation process is simple and the preparation cost is low, which has practical application value for further promoting the development of semiconductor gas sensing devices. The method provided by the invention can greatly improve the stability of Fe2O3, the sensitivity to methanol and the response time, so that the metal oxide system materials have a broader application prospect in the field of gas sensors. Specific embodiments
[0015] 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.
[0016] Example 1 A nanocomposite iron oxide material for a gas sensor is prepared according to the following steps: (1) Dissolve the long-chain alkylamine decaamine in methanol solution to a concentration of 5 g / L, labeled as solution A; (2) Dissolve 6.91 g of ferric chloride and 5.73 g of sodium hydroxide in deionized water, marked as B. (3) Slowly add B to solution A and react at normal pressure and low temperature of 0°C for 30 h. The product is centrifuged, washed with methanol solution three times, and dried in an oven at 60°C to obtain product C composite nano-Fe2O3 material; (4) Dissolve 0.01 mol of copper oxide in deionized water, stir for 10 min, and then add 10 mL of ammonia water to obtain solution D. (5) Dissolve 10 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E; (6) Add solution E dropwise into solution D and stir for 5 h to obtain solution F. (7) Adding the product C composite nano-SnO2 material to solution F to obtain solution G; (8) 5 mmol of reducing agent sodium borohydride was added dropwise to solution G and stirred for 6 h. The resulting precipitate was washed several times with deionized water and ethanol, filtered and dried to obtain the final product.
[0017] 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 180° C., and the sensitivity to 1 ppm acetone gas reached 16.12.
[0018] Example 2 A nanocomposite iron oxide material for a gas sensor is prepared according to the following steps: (1) Dissolve dodecylamine in ethanol solution to a concentration of 10 g / L, labeled as solution A; (2) Dissolve 5.85 g of ferric chloride and 5.98 g of sodium hydroxide in deionized water, marked as B; (3) Slowly add B to solution A, react at normal pressure and low temperature of 10 °C for 20 h, centrifuge the product, wash it with ethanol solution 5 times, and dry it in an oven at 80 °C to obtain product C composite nano-Fe2O3 material; (4) Dissolve 0.02 mol of copper oxide in deionized water, stir for 10 min, and then add 5 mL of ammonia water to obtain solution D. (5) Dissolve 5 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E. (6) Add solution E dropwise into solution D and stir for 5 h to obtain solution F. (7) Adding the prepared product C composite nano-SnO2 material to solution F to obtain solution G; (8) 2 mmol of reducing agent ascorbic acid was added dropwise to solution G and stirred for 3 h. The resulting precipitate was washed several times with deionized water and ethanol, filtered and dried to obtain the final product, a nanocomposite iron oxide material for gas sensors.
[0019] The powder prepared in this embodiment was dispersed and coated on a six-pin ceramic tube gas sensor test element. The response to acetone gas at different concentrations was tested using a WS-30A gas sensor test system. The working temperature was 180° C., and the sensitivity to 1 ppm methanol gas reached 18.8.
[0020] Example 3 A nanocomposite iron oxide material for a gas sensor is prepared according to the following steps: (1) Dissolve decaamine in ethanol solution to a concentration of 5 g / L, labeled as solution A; (2) Dissolve 6.463 g of ferric chloride and 7.93 g of sodium hydroxide in deionized water, marked as B; (3) Slowly add B to solution A, react at normal pressure and low temperature of 20 °C for 15 h, centrifuge the product, wash it with ethanol solution for 5 times, and dry it in an oven at 80 °C to obtain product C composite nano-Fe2O3 material; (4) Dissolve 0.005 mol of copper oxide in deionized water, stir for 10 min, and then add 5 mL of ammonia water to obtain solution D. (5) Dissolve 5 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E. (6) Add solution E dropwise into solution D and stir for 5 h to obtain solution F. (7) Adding the prepared product C composite nano-SnO2 material to solution F to obtain solution G; (8) 2 mmol of reducing agent sodium borohydride was added dropwise to solution G and stirring was continued for 3 h. The obtained precipitate was washed several times with deionized water and ethanol, filtered and dried to obtain the final product, a nanocomposite iron oxide material for gas sensor.
[0021] The powder prepared in this embodiment was dispersed and coated on a six-pin ceramic tube gas sensor test element. The response to acetone gas at different concentrations was tested using a WS-30A gas sensor test system. The working temperature was 180° C., and the sensitivity to 1 ppm methanol gas reached 14.7.
Claims
1. A method for preparing a nanocomposite iron oxide material for a gas sensor, characterized in that: The steps include: (1) Dissolve the long-chain alkylamine in an alcohol solution to a concentration of 5-100 g / L, labeled as solution A; (2) Dissolve ferric chloride and sodium hydroxide in deionized water respectively to a molar ratio of 1:3-1:5, marked as B; (3) Slowly add B dropwise to solution A, react at normal pressure and low temperature of 0-40 °C for 2-30 h, centrifuge the product, wash it with alcohol solution 3-5 times, and dry it in an oven at 60-80 °C to obtain product C; (4) Dissolve 0.005-0.01 mol of copper oxide in deionized water, stir for 10-20 min, and then add 5-10 mL of aqueous ammonia to obtain solution D. (5) Dissolve 5-10 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E. (6) Add solution E dropwise into solution D and stir for 5-10 h to obtain solution F. (7) Add product C to solution F to obtain solution G; (8) Add 2–5 mmol of reducing agent dropwise into solution G and continue stirring for 3–6 h. Wash the resulting precipitate several times with deionized water and ethanol, filter, and dry to obtain the final product.
2. The method for preparing the nanocomposite iron oxide material for gas sensor according to claim 1, characterized in that: The long-chain alkylamine is one of decaamine and dodecylamine or a combination thereof.
3. The method for preparing the nanocomposite iron oxide material for gas sensor according to claim 1, characterized in that: The alcohol is one of methanol, ethanol or propanol or a combination thereof.
4. The method for preparing the nanocomposite iron oxide material for gas sensor according to claim 1, characterized in that: The reducing agent is ascorbic acid or sodium borohydride or a combination thereof.
5. The method for preparing the nanocomposite iron oxide material for gas sensor according to any one of claims 1 to 4, characterized in that: Prepare as follows: (1) Dissolve the long-chain alkylamine decaamine in methanol solution to a concentration of 5 g / L, labeled as solution A; (2) Dissolve 6.91 g of ferric chloride and 5.73 g of sodium hydroxide in deionized water, marked as B. (3) Slowly add B to solution A and react at normal pressure and low temperature of 0°C for 30 h. The product is centrifuged, washed with methanol solution three times, and dried in an oven at 60°C to obtain product C composite nano-Fe2O3 material; (4) Dissolve 0.01 mol of copper oxide in deionized water, stir for 10 min, and then add 10 mL of ammonia water to obtain solution D. (5) Dissolve 10 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E; (6) Add solution E dropwise into solution D and stir for 5 h to obtain solution F. (7) Adding the product C composite nano-SnO2 material to solution F to obtain solution G; (8) 5 mmol of reducing agent sodium borohydride was added dropwise to solution G and stirred for 6 h. The resulting precipitate was washed several times with deionized water and ethanol, filtered and dried to obtain the final product.
6. The method for preparing the nanocomposite iron oxide material for gas sensor according to any one of claims 1 to 4, characterized in that: Prepare as follows: (1) Dissolve dodecylamine in ethanol solution to a concentration of 10 g / L, labeled as solution A; (2) Dissolve 5.85 g of ferric chloride and 5.98 g of sodium hydroxide in deionized water, marked as B; (3) Slowly add B to solution A, react at normal pressure and low temperature of 10 °C for 20 h, centrifuge the product, wash it with ethanol solution 5 times, and dry it in an oven at 80 °C to obtain product C composite nano-Fe2O3 material; (4) Dissolve 0.02 mol of copper oxide in deionized water, stir for 10 min, and then add 5 mL of ammonia water to obtain solution D; (5) Dissolve 5 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E; (6) Add solution E dropwise into solution D and stir for 5 h to obtain solution F; (7) adding the prepared product C composite nano-SnO2 material to solution F to obtain solution G; (8) 2 mmol of reducing agent ascorbic acid was added dropwise to solution G and stirred for 3 h. The obtained precipitate was washed several times with deionized water and ethanol, filtered and dried to obtain the final product, a nanocomposite iron oxide material for gas sensor.
7. The method for preparing the nanocomposite iron oxide material for gas sensor according to any one of claims 1 to 4, characterized in that: Prepare as follows: (1) Dissolve decaamine in ethanol solution to a concentration of 5 g / L, labeled as solution A; (2) Dissolve 6.463 g of ferric chloride and 7.93 g of sodium hydroxide in deionized water, marked as B; (3) B was slowly added dropwise to solution A, and the reaction was carried out at normal pressure and low temperature of 20°C for 15 h. The product was centrifuged, washed with ethanol solution for 5 times, and dried in an oven at 80°C to obtain product C, a composite nano-Fe2O3 material; (4) Dissolve 0.005 mol of copper oxide in deionized water, stir for 10 min, and then add 5 mL of ammonia water to obtain solution D. (5) Dissolve 5 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water and stir until transparent to obtain solution E. (6) Add solution E dropwise into solution D and stir for 5 h to obtain solution F. (7) Adding the prepared product C composite nano-SnO2 material to solution F to obtain solution G; (8) 2 mmol of reducing agent sodium borohydride was added dropwise to solution G and stirring was continued for 3 h. The obtained precipitate was washed several times with deionized water and ethanol, filtered and dried to obtain the final product, a nanocomposite iron oxide material for gas sensor.
8. A nanocomposite iron oxide material for gas sensor, characterized in that Prepared according to any one of claims 1 to 7.
9. Application of a nano-composite iron oxide material in a gas sensor for methanol gas.