Preparation method of ZnO composite nano-material, and product and application of ZnO composite nano-material

Abstract

The invention discloses a preparation method of a ZnO composite nanomaterial as well as a product and application of the ZnO composite nanomaterial. The preparation method comprises the following steps: dissolving long-chain alkylamine into an alcohol solution to obtain A; respectively dissolving zinc nitrate and sodium hydroxide in deionized water to obtain B; slowly dropwise adding B into A, and centrifugally washing and drying the product to obtain a product C; dissolving copper oxide in deionized water, stirring, and dropwise adding ammonia water to obtain D; dissolving sodium dodecyl benzene sulfonate in deionized water, and stirring to be transparent to obtain a solution E; dropwise adding E into D, and stirring to obtain F after dropwise adding; adding C into F to obtain G; dropwise adding a reducing agent into the solution G, continuously stirring, washing the obtained precipitate, performing suction filtration, and drying to obtain a final product. According to the method provided by the invention, the stability, the sensitivity to methanol and the response time of ZnO can be greatly improved, so that a metal oxide system material has a wider application prospect in the field of gas sensors.

Description

Technical Field

[0001] The present invention relates to the technical field of gas sensors, and relates to a method for preparing a ZnO composite nanomaterial, a product thereof, and application thereof, and specifically refers to a method for preparing a ZnO composite nanomaterial for a gas sensor. 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. ZnO 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 purpose of the present invention is to provide a method for preparing a ZnO composite nano material.

[0005] Another object of the present invention is to provide a ZnO composite nanomaterial product 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 ZnO composite nanomaterial, the specific steps of the method are: (1) Dissolve the long-chain alkylamine in an alcohol solution to a concentration of 5-100 g / L, labeled as solution A; (2) Dissolve zinc nitrate and sodium hydroxide in deionized water respectively to a molar ratio of 1:2-1:5, marked as solution B; (3) Solution B is slowly added dropwise to solution A, and the reaction is carried out at normal pressure and low temperature of 0-40 °C for 2-30 h. The product is centrifuged, washed with an alcohol solution for 3-5 times, and dried in an oven at 60-80 °C to obtain product C. (4) Dissolve 0.005-0.01 mol copper oxide in deionized water, stir for 10-20 min, then add 5-10 mL ammonia water to obtain solution D; dissolve 5-10 g sodium dodecylbenzene sulfonate in 50 mL deionized water, stir until transparent, to obtain solution E; add solution E dropwise into solution D, stir for 5-10 h, to obtain solution F; add product C into solution F, to obtain solution G; add 2-5 mmol reducing agent dropwise into solution G, and continue stirring for 3-6 h. Wash the obtained precipitate with deionized water and ethanol several times, filter and dry 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 ZnO composite nano material, which is characterized in that it is prepared according to any of the above methods.

[0012] The invention provides application of a ZnO composite nano material in methanol gas detection.

[0013] The present invention provides a simple method for preparing ZnO composite nanomaterials, which can increase the specific surface area and active sites of the material surface, greatly improve the gas sensing performance of the nanomaterials, and has a simple preparation process and low preparation cost, and has practical application value for further promoting the development of semiconductor gas sensing devices.

[0014] 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.

[0015] The method provided by the present invention is simple and feasible, and can greatly improve the stability, sensitivity to methanol and response time of ZnO, so that the metal oxide system materials have broader application prospects in the field of gas sensors. DETAILED DESCRIPTION

[0016] 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.

[0017] Example 1 A ZnO composite nanomaterial is prepared according to the following steps: (1) Dissolve decaamine in methanol solution to a concentration of 5 g / L, labeled as solution A; (2) Dissolve 4.91 g zinc nitrate and 2.73 g sodium hydroxide in deionized water, respectively, and label it as solution B; (3) Solution B was slowly added dropwise to solution A, and the reaction was carried out at normal pressure and low temperature of 0 °C for 30 h. The product was centrifuged, washed with methanol solution for 3 times, and dried in an oven at 60 °C to obtain mesoporous nano ZnO material; (4) Dissolve 0.005 mol copper oxide in deionized water, stir for 10 min, then add 5 mL ammonia water to obtain solution D; dissolve 5 g sodium dodecylbenzene sulfonate in 50 mL deionized water, stir until transparent, and obtain solution F; add solution E dropwise into solution D, stir for 5 h after the addition, and obtain solution F; add the mesoporous nano ZnO material prepared in step (3) into solution F, and obtain solution G; add 2 mmol reducing agent ascorbic acid dropwise into solution G, and continue stirring for 3 h. Wash the obtained precipitate with deionized water and ethanol several times, filter and dry to obtain the final product.

[0018] 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 29.6.

[0019] Example 2 A ZnO composite nanomaterial is prepared in the following steps, similar to the embodiment: (1) Dissolve dodecylamine in ethanol solution to a concentration of 10 g / L, labeled as solution A; (2) Dissolve 2.85 g zinc nitrate and 3.98 g sodium hydroxide in deionized water, respectively, and label it as solution B; (3) Solution B was slowly added dropwise to solution A, and the reaction was carried out at normal pressure and low temperature of 10 °C for 20 h. The product was centrifuged, washed with ethanol solution for 5 times, and dried in an oven at 80 °C to obtain mesoporous nano ZnO material; (4) Dissolve 0.005 mol copper oxide in deionized water, stir for 10 min, then add 5 mL ammonia water to obtain solution D; dissolve 5 g sodium dodecylbenzene sulfonate in 50 mL deionized water, stir until transparent, and obtain solution E; add solution E dropwise into solution D, stir for 5 h after the addition, and obtain solution F; add the mesoporous nano ZnO material prepared in step (3) into solution F, and obtain solution G; add 2 mmol reducing agent sodium borohydride dropwise into solution G, and continue stirring for 3 h. Wash the obtained precipitate with deionized water and ethanol several times, and then filter and dry to obtain the final product.

[0020] 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 21.9.

[0021] Example 3 A ZnO composite nanomaterial is prepared in the following steps, similar to the embodiment: (1) Dissolve decaamine in ethanol solution to a concentration of 5 g / L, labeled as solution A; (2) Dissolve 3.463 g zinc nitrate and 4.93 g sodium hydroxide in deionized water, respectively, and label it as solution B; (3) Solution 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 a mesoporous nano ZnO material; (4) Dissolve 0.01 mol copper oxide in deionized water, stir for 10 min, then add 10 mL of ammonia water to obtain solution D; dissolve 10 g of sodium dodecylbenzene sulfonate in 50 mL of deionized water, stir until transparent, and obtain solution E; add solution E dropwise into solution D, stir for 5 h after the addition, and obtain solution F; add the mesoporous nano ZnO material prepared in step (3) into solution F, and obtain solution G; add 5 mmol of reducing agent sodium borohydride dropwise into solution G and continue stirring for 6 h. Wash the obtained precipitate with deionized water and ethanol several times, filter and dry to obtain the final product.

[0022] 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 21.7.

Claims

1. A method for preparing a ZnO composite nanomaterial, 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 zinc nitrate and sodium hydroxide in deionized water respectively to a molar ratio of 1:2-1:5, marked as solution B; (3) Slowly add solution 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 copper oxide in deionized water, stir for 10-20 min, then add 5-10 mL ammonia water to obtain solution D; dissolve 5-10 g sodium dodecylbenzene sulfonate in 50 mL deionized water, stir until transparent, to obtain solution E; add solution E dropwise into solution D, stir for 5-10 h, to obtain solution F; add product C into solution F, to obtain solution G; add 2-5 mmol reducing agent dropwise into solution G, and continue stirring for 3-6 h. Wash the obtained precipitate with deionized water and ethanol several times, filter and dry to obtain the final product.

2. The method for preparing the ZnO composite nanomaterial 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 ZnO composite nanomaterial 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 ZnO composite nanomaterial 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 ZnO composite nanomaterial according to any one of claims 1 to 4, characterized in that: Prepare as follows: (1) Dissolve decaamine in methanol solution to a concentration of 5 g / L, labeled as solution A; (2) Dissolve 4.91 g zinc nitrate and 2.73 g sodium hydroxide in deionized water, respectively, and label it as solution B; (3) Solution B was slowly added dropwise to solution A, and the reaction was carried out at normal pressure and low temperature of 0 °C for 30 h. The product was centrifuged, washed with methanol solution for 3 times, and dried in an oven at 60 °C to obtain mesoporous nano ZnO material; (4) Dissolve 0.005 mol copper oxide in deionized water, stir for 10 min, then add 5 mL ammonia water to obtain solution D; dissolve 5 g sodium dodecylbenzene sulfonate in 50 mL deionized water, stir until transparent, and obtain solution F; add solution E dropwise into solution D, stir for 5 h after the addition, and obtain solution F; add the mesoporous nano ZnO material prepared in step (3) into solution F, and obtain solution G; add 2 mmol reducing agent ascorbic acid dropwise into solution G, and continue stirring for 3 h. Wash the obtained precipitate with deionized water and ethanol several times, and then filter and dry to obtain the final product.

6. The method for preparing the ZnO composite nanomaterial 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 2.85 g zinc nitrate and 3.98 g sodium hydroxide in deionized water, respectively, and label it as solution B; (3) Solution B was slowly added dropwise to solution A, and the reaction was carried out at normal pressure and low temperature of 10 °C for 20 h. The product was centrifuged, washed with ethanol solution for 5 times, and dried in an oven at 80 °C to obtain mesoporous nano ZnO material; (4) Dissolve 0.005 mol copper oxide in deionized water, stir for 10 min, then add 5 mL ammonia water to obtain solution D; dissolve 5 g sodium dodecylbenzene sulfonate in 50 mL deionized water, stir until transparent, and obtain solution E; add solution E dropwise into solution D, stir for 5 h after the addition, and obtain solution F; add the mesoporous nano ZnO material prepared in step (3) into solution F, and obtain solution G; add 2 mmol reducing agent sodium borohydride dropwise into solution G, and continue stirring for 3 h. Wash the obtained precipitate with deionized water and ethanol several times, filter and dry to obtain the final product.

7. A ZnO composite nanomaterial, characterized in that Prepared according to any one of claims 1 to 6.

8. Use of the ZnO composite nanomaterial according to claim 7 in methanol gas detection.