阅读说明：本技术 一种铝掺杂氧化锌纳米棒修饰聚苯胺的气敏材料及其制法 (Air-sensitive material of polyaniline modified by aluminum-doped zinc oxide nano-rod and preparation method thereof ) 是由 俞中毅 于 2020-12-14 设计创作，主要内容包括：本发明涉及气敏材料技术领域,且公开了一种铝掺杂氧化锌纳米棒修饰聚苯胺的气敏材料,一步水热得到铝掺杂氧化锌纳米棒,具有超高的比表面积,铝元素掺入氧化锌晶格,使其缺陷增多,暴露更多的活性位点,降低氧化锌工作温度,制备羧基化铝掺杂氧化锌纳米棒,置于硫酸溶液中,水解产生COO-,再加入聚苯胺,代替COOH中的H,二者共价接枝,均匀分散,进一步提高比表面积,加快气体的扩散速度,提高响应和恢复性能,在紫外光照射下,空穴从氧化锌的价带迁移到聚苯胺的价带上,光生电子和空穴有效分离,降低光生电子-空穴复合率,使得铝掺杂氧化锌纳米棒修饰聚苯胺气敏材料具有优异的室温乙醇气敏性能。(The invention relates to the technical field of gas-sensitive materials, and discloses a gas-sensitive material of polyaniline modified by aluminum-doped zinc oxide nano-rods, which is prepared by one-step hydrothermal method, wherein the aluminum-doped zinc oxide nano-rods have ultrahigh specific surface area, aluminum element is doped into zinc oxide crystal lattices, so that the defects are increased, more active sites are exposed, the working temperature of zinc oxide is reduced, carboxylated aluminum-doped zinc oxide nano-rods are prepared and placed in sulfuric acid solution, hydrolyzing to generate COO-, adding polyaniline to replace H in COOH, covalently grafting and uniformly dispersing the COO and the polyaniline, further improving the specific surface area, accelerating the diffusion speed of gas, improving the response and recovery performance, under the irradiation of ultraviolet light, the holes are transferred from the valence band of zinc oxide to the valence band of polyaniline, the photoproduction electrons and the holes are effectively separated, the recombination rate of the photoproduction electrons and the holes is reduced, so that the polyaniline gas-sensitive material modified by the aluminum-doped zinc oxide nano-rod has excellent ethanol gas-sensitive performance at room temperature.)

1. An air-sensitive material of polyaniline modified by aluminum-doped zinc oxide nano-rods is characterized in that: the preparation method of the air-sensitive material of polyaniline modified by the aluminum-doped zinc oxide nano-rods comprises the following steps:

(1) adding zinc nitrate, aluminum nitrate and sodium hydroxide into deionized water according to the mass ratio of 100:6-7:25-31, uniformly stirring, transferring the mixed solution into a reaction kettle, placing the reaction kettle in a hydrothermal device, reacting for 12-18h at the temperature of 160-200 ℃, filtering, washing and drying to obtain an aluminum-doped zinc oxide nano rod;

(2) adding ethanol and vinyl trimethoxy silane into deionized water, ultrasonically dispersing uniformly, dropwise adding ammonia water, adjusting the pH value of the solution to 9-10, adding an aluminum-doped zinc oxide nanorod into the mixed solution, reacting at 50-60 ℃ for 2-4h, cooling, filtering, washing and drying to obtain an aluminum-vinyl-doped zinc oxide nanorod;

(3) adding an aluminum vinyl doped zinc oxide nanorod into dilute sulfuric acid, stirring uniformly at 5-10 ℃, then respectively adding sodium nitrate and potassium permanganate, stirring uniformly at low temperature, heating to 40-50 ℃ for reaction for 2-4h, then adding deionized water into a reaction bottle, heating to 70-80 ℃ for reaction for 4-6h, cooling, filtering, washing and drying to obtain a carboxylated aluminum doped zinc oxide nanorod;

(4) adding p-toluenesulfonic acid into dilute sulfuric acid, stirring uniformly to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, stirring uniformly to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylation doped zinc oxide nano-rods into the mixed acid, stirring uniformly, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring and reacting for 6-8h, filtering, washing and drying to obtain the air-sensitive material of polyaniline modified by the aluminum doped zinc oxide nano-rods.

2. The gas-sensitive material for modifying polyaniline by using the aluminum-doped zinc oxide nanorod as claimed in claim 1, wherein the gas-sensitive material comprises: the medium-temperature hydrothermal device comprises a main body, a motor is movably connected to the bottom of the main body, a partition plate is movably connected to the middle of the main body, a flange platform is movably connected to the top of the motor, a fixing frame is movably connected to the top of the flange platform, a reaction kettle is movably connected to the inside of the fixing frame, a ventilation pipe is movably connected to the inside of the main body, an air inlet is movably connected to the right side of the ventilation pipe, an air inlet fan is movably connected to the inside of the air inlet, an air outlet is movably connected to the left side of the ventilation pipe.

3. The gas-sensitive material for modifying polyaniline by using the aluminum-doped zinc oxide nanorod as claimed in claim 1, wherein the gas-sensitive material comprises: the mass ratio of the vinyltrimethoxysilane to the aluminum-doped zinc oxide nano-rod in the step (2) is 100-200: 100.

4. The gas-sensitive material for modifying polyaniline by using the aluminum-doped zinc oxide nanorod as claimed in claim 1, wherein the gas-sensitive material comprises: the mass ratio of the aluminum vinyl doped zinc oxide nano-rod, the sodium nitrate and the potassium permanganate in the step (3) is 100:40-60: 250-400.

5. The gas-sensitive material for modifying polyaniline by using the aluminum-doped zinc oxide nanorod as claimed in claim 1, wherein the gas-sensitive material comprises: in the step (4), the mass ratio of the p-toluenesulfonic acid, the ammonium persulfate, the polyvinylpyrrolidone, the aniline and the aluminum carboxylation doped zinc oxide nano-rod is 1.5-2:9-12:0.2-0.3:4-6: 100.

Technical Field

The invention relates to the technical field of gas-sensitive materials, in particular to a gas-sensitive material of polyaniline modified by aluminum-doped zinc oxide nano-rods and a preparation method thereof.

Background

The survey results of the world health organization show that about 50% of traffic accidents are caused by drunk driving, which has become the first killer of traffic accidents, and thus, more and more researchers focus on high-sensitivity ethanol gas sensors, currently used ethanol gas sensors are generally oxide semiconductor gas sensors, tin dioxide, titanium dioxide, zinc oxide and the like are common, zinc oxide is a direct band gap and wide band gap semiconductor, has various morphological structures and good gas sensing performance, and is always the research object of gas sensing material researchers.

The gas-sensitive sensor made of the zinc oxide material has the advantages of high response speed, long service life, low cost and the like, but the gas-sensitive sensor has the defects of high working temperature and low sensitivity, the application of the gas-sensitive sensor is limited, the ultraviolet irradiation can effectively reduce the working temperature, but the photoproduction electron-hole recombination speed of the zinc oxide is too high, the zinc oxide cannot be applied in a large scale, the polyaniline is a pi conjugated high polymer and has good chemical stability and high conductivity, and the polyaniline is compounded with the zinc oxide to form a nano material, so that the gas-sensitive performance of the sensor can be effectively improved, and therefore, the problem is solved by adopting a mode of modifying the polyaniline by using an aluminum-doped zinc oxide nano rod.

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides an air-sensitive material of polyaniline modified by aluminum-doped zinc oxide nano-rods and a preparation method thereof, and solves the problems of higher working temperature and lower sensitivity of the zinc oxide air-sensitive material.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: the preparation method of the air-sensitive material for modifying polyaniline by the aluminum-doped zinc oxide nanorod comprises the following steps:

(1) adding deionized water, zinc nitrate, aluminum nitrate and sodium hydroxide into a reaction bottle in a mass ratio of 100:6-7:25-31, uniformly stirring, transferring the mixed solution into a reaction kettle, placing the reaction kettle in a hydrothermal device, reacting for 12-18h at the temperature of 160-200 ℃, filtering, washing with deionized water and absolute ethyl alcohol, and drying to obtain an aluminum-doped zinc oxide nano rod;

(2) adding deionized water, ethanol and vinyl trimethoxy silane into a reaction bottle, performing ultrasonic treatment for 5-15min to disperse uniformly, dropwise adding ammonia water, adjusting the pH of the solution to 9-10, adding an aluminum-doped zinc oxide nanorod into the mixed solution, reacting for 2-4h at 50-60 ℃, cooling, filtering, washing with deionized water and absolute ethanol, and drying to obtain an aluminum-vinyl-doped zinc oxide nanorod;

(3) adding dilute sulfuric acid and an aluminum vinyl doped zinc oxide nano rod into a reaction bottle, stirring for 10-20min at 5-10 ℃, then respectively adding sodium nitrate and potassium permanganate, continuously stirring for 20-40min at low temperature, then heating to 40-50 ℃ for reaction for 2-4h, then adding deionized water into the reaction bottle, then heating to 70-80 ℃ for reaction for 4-6h, cooling, filtering, washing with deionized water, and drying to obtain a carboxylated aluminum doped zinc oxide nano rod;

(4) adding dilute sulfuric acid and p-toluenesulfonic acid into a reaction bottle, uniformly stirring to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, uniformly stirring to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylate doped zinc oxide nano-rods into the mixed acid, uniformly stirring, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring for reaction for 6-8 hours, centrifugally washing with deionized water and absolute ethyl alcohol, and drying to obtain the gas-sensitive material of polyaniline modified by the aluminum doped zinc oxide nano-rods.

Preferably, the hydrothermal device in the step (1) comprises a main body, a motor is movably connected to the bottom of the main body, a partition plate is movably connected to the middle of the main body, a flange platform is movably connected to the top of the motor, a fixing frame is movably connected to the top of the flange platform, a reaction kettle is movably connected to the inside of the fixing frame, a ventilation pipe is movably connected to the inside of the main body, an air inlet is movably connected to the right side of the ventilation pipe, an air inlet fan is movably connected to the inside of the air inlet, an air outlet is movably connected to the left side of the.

Preferably, the mass ratio of the vinyltrimethoxysilane to the aluminum-doped zinc oxide nano-rod in the step (2) is 100-200: 100.

Preferably, the mass ratio of the aluminum vinyl doped zinc oxide nano rod, the sodium nitrate and the potassium permanganate in the step (3) is 100:40-60: 250-400.

Preferably, in the step (4), the mass ratio of the p-toluenesulfonic acid to the ammonium persulfate to the polyvinylpyrrolidone to the aluminum carboxylate doped zinc oxide nano-rods is 1.5-2:9-12:0.2-0.3:4-6: 100.

(III) advantageous technical effects

Compared with the prior art, the invention has the following beneficial technical effects:

the air-sensitive material for modifying polyaniline by using the aluminum-doped zinc oxide nanorod takes zinc nitrate and aluminum nitrate as raw materials, the aluminum-doped zinc oxide nanorod is obtained by one-step hydrothermal method in an alkaline environment, the specific surface area is ultrahigh, aluminum elements are doped into crystal lattices of zinc oxide, so that the defects of the zinc oxide are increased, more active sites are exposed, more oxygen molecules are bound on the surface of the zinc oxide, more oxygen anions are generated, the air-sensitive performance of the zinc oxide is effectively improved, the defects are increased, the working temperature of the zinc oxide is reduced, and the zinc oxide can have enough energy to react with the oxygen anions on the surface at a lower temperature.

The air-sensitive material of polyaniline modified by aluminum-doped zinc oxide nano-rod is prepared by performing condensation reaction on the aluminum-doped zinc oxide nano-rod and vinyl trimethoxy silane in a mixed solution of ethanol and water to obtain an aluminum-vinyl-doped zinc oxide nano-rod, placing the aluminum-vinyl-doped zinc oxide nano-rod in a strong oxidizing solution to obtain a carboxylated aluminum-doped zinc oxide nano-rod, placing the carboxylated aluminum-doped zinc oxide nano-rod in a sulfuric acid solution, hydrolyzing the carboxylated aluminum-doped zinc oxide nano-rod to generate COO < - > which is electronegative, adding aniline and an oxidant to prepare electropositive polyaniline macromolecules to replace H in COOH, covalently grafting the carboxylated aluminum-doped zinc oxide nano-rod and the polyaniline macromolecules, uniformly dispersing the polyaniline macromolecules on a skeleton, reducing agglomeration, improving the regularity of polyaniline molecular chains, further improving the specific surface area, and providing more active sites for chemically adsorbing oxygen to react with test gas, the sensitivity of the gas-sensitive material is increased, the diffusion speed of gas is accelerated, the response and recovery performance are improved, zinc oxide can generate photoproduction electron-hole pairs under the irradiation of ultraviolet light, holes are transferred to the valence band of polyaniline from the valence band of the zinc oxide, and trap energy levels can be generated on an organic-inorganic interface to capture the holes, so that the photoproduction electrons and the holes can be effectively separated, and the recombination rate of the photoproduction electrons and the holes is reducedThe combination of the holes and the chemisorbed oxygen ions reduces the recombination with the photo-generated electrons, which are then coupled with O on the surface of the material₂The photo-generated oxygen ions with higher reaction activity are generated in a combined manner, the photo-generated oxygen ions can react with ethanol gas at room temperature to generate acetaldehyde and water, photo-generated electrons are released to return to the surface of the zinc oxide, the resistance of the material is reduced, and the gas-sensitive effect is generated, so that the polyaniline gas-sensitive material modified by the aluminum-doped zinc oxide nano-rod has excellent ethanol gas-sensitive performance at room temperature.

Drawings

FIG. 1 is a schematic structural view of a hydrothermal device in front view;

fig. 2 is a schematic top view of the flange platform.

1. A main body; 2. a motor; 3. a partition plate; 4. a flange platform; 5. a fixed mount; 6. a reaction kettle; 7. a vent pipe; 8. an air inlet; 9. an air inlet fan; 10. an air outlet; 11. an exhaust fan.

Detailed Description

To achieve the above object, the present invention provides the following embodiments and examples: a preparation method of the air-sensitive material of polyaniline modified by the aluminum-doped zinc oxide nano-rods comprises the following steps:

(1) adding deionized water, zinc nitrate, aluminum nitrate and sodium hydroxide into a reaction bottle with the mass ratio of 100:6-7:25-31, uniformly stirring, transferring the mixed solution into a reaction kettle and placing the reaction kettle in a hydrothermal device, wherein the hydrothermal device comprises a main body, the bottom of the main body is movably connected with a motor, the middle of the main body is movably connected with a partition plate, the top of the motor is movably connected with a flange platform, the top of the flange platform is movably connected with a fixed frame, the inside of the fixed frame is movably connected with the reaction kettle, the inside of the main body is movably connected with a ventilation pipe, the right side of the ventilation pipe is movably connected with an air inlet, the inside of the air inlet is movably connected with an air inlet fan, the left side of the ventilation pipe is movably connected with an air outlet, the inside of the air outlet is movably connected with an exhaust fan, reacting, obtaining an aluminum-doped zinc oxide nanorod;

(2) adding deionized water, ethanol and vinyl trimethoxy silane into a reaction bottle, performing ultrasonic treatment for 5-15min to disperse uniformly, dripping ammonia water, adjusting the pH value of the solution to 9-10, adding an aluminum-doped zinc oxide nano rod into the mixed solution, reacting for 2-4h at 50-60 ℃ at the mass ratio of 100:100, cooling, filtering, washing with deionized water and absolute ethyl alcohol, and drying to obtain an aluminum vinyl doped zinc oxide nano rod;

(3) adding dilute sulfuric acid and an aluminum vinyl doped zinc oxide nano rod into a reaction bottle, stirring for 10-20min at 5-10 ℃, then respectively adding sodium nitrate and potassium permanganate, wherein the mass ratio of the aluminum vinyl doped zinc oxide nano rod to the sodium nitrate to the potassium permanganate is 100:40-60:250-400, continuing stirring at low temperature for 20-40min, then heating to 40-50 ℃ for reaction for 2-4h, then adding deionized water into the reaction bottle, then heating to 70-80 ℃ for reaction for 4-6h, cooling, filtering, washing with deionized water, and drying to obtain a carboxylated aluminum doped zinc oxide nano rod;

(4) adding dilute sulfuric acid and p-toluenesulfonic acid into a reaction bottle, uniformly stirring to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, uniformly stirring to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylate doped zinc oxide nano rods into the mixed acid, wherein the mass ratio of the p-toluenesulfonic acid, the ammonium persulfate, the polyvinylpyrrolidone, the aniline and the aluminum carboxylate doped zinc oxide nano rods is 1.5-2:9-12:0.2-0.3:4-6:100, uniformly stirring, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring for reaction for 6-8h, centrifugally washing with deionized water and absolute ethyl alcohol, and drying to obtain the air-sensitive material modified by the aluminum doped zinc oxide nano rods.

Example 1

(1) Adding deionized water, zinc nitrate, aluminum nitrate and sodium hydroxide into a reaction bottle in a mass ratio of 100:6:25, uniformly stirring, transferring the mixed solution into a reaction kettle, placing the reaction kettle in a hydrothermal device, the hydrothermal device comprises a main body, wherein the bottom of the main body is movably connected with a motor, the middle of the main body is movably connected with a partition plate, the top of the motor is movably connected with a flange platform, the top of the flange platform is movably connected with a fixed frame, the inside of the fixed frame is movably connected with a reaction kettle, the inside of the main body is movably connected with a ventilation pipe, the right side of the ventilation pipe is movably connected with an air inlet, the inside of the air inlet is movably connected with an air inlet fan, the left side of the ventilation pipe is movably connected, reacting for 12 hours at 160 ℃, filtering, washing with deionized water and absolute ethyl alcohol, and drying to obtain the aluminum-doped zinc oxide nano rod;

(2) adding deionized water, ethanol and vinyl trimethoxy silane into a reaction bottle, performing ultrasonic treatment for 5min to disperse uniformly, dripping ammonia water, adjusting the pH value of the solution to 9, adding an aluminum-doped zinc oxide nano rod into the mixed solution, reacting for 2h at 50 ℃ with the mass ratio of the vinyl trimethoxy silane to the aluminum-doped zinc oxide nano rod being 100:100, cooling, filtering, washing with deionized water and absolute ethanol, and drying to obtain an aluminum vinyl-doped zinc oxide nano rod;

(3) adding dilute sulfuric acid and an aluminum vinyl doped zinc oxide nano rod into a reaction bottle, stirring for 10min at 5 ℃, then respectively adding sodium nitrate and potassium permanganate, wherein the mass ratio of the aluminum vinyl doped zinc oxide nano rod to the sodium nitrate to the potassium permanganate is 100:40:250, continuing stirring at low temperature for 20min, then heating to 40 ℃ for reaction for 2h, then adding deionized water into the reaction bottle, heating to 70 ℃ for reaction for 4h, cooling, filtering, washing with deionized water, and drying to obtain a carboxylated aluminum doped zinc oxide nano rod;

(4) adding dilute sulfuric acid and p-toluenesulfonic acid into a reaction bottle, uniformly stirring to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, uniformly stirring to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylate doped zinc oxide nano rods into the mixed acid, wherein the mass ratio of the p-toluenesulfonic acid, the ammonium persulfate, the polyvinylpyrrolidone, the aniline and the aluminum carboxylate doped zinc oxide nano rods is 1.5:9:0.2:4:100, uniformly stirring, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring for reacting for 6 hours, centrifugally washing with deionized water and absolute ethyl alcohol, and drying to obtain the air-sensitive material modified by the aluminum doped zinc oxide nano rods.

Example 2

(1) Adding deionized water, zinc nitrate, aluminum nitrate and sodium hydroxide into a reaction bottle in a mass ratio of 100:6.5:28, uniformly stirring, transferring the mixed solution into a reaction kettle, placing the reaction kettle in a hydrothermal device, the hydrothermal device comprises a main body, wherein the bottom of the main body is movably connected with a motor, the middle of the main body is movably connected with a partition plate, the top of the motor is movably connected with a flange platform, the top of the flange platform is movably connected with a fixed frame, the inside of the fixed frame is movably connected with a reaction kettle, the inside of the main body is movably connected with a ventilation pipe, the right side of the ventilation pipe is movably connected with an air inlet, the inside of the air inlet is movably connected with an air inlet fan, the left side of the ventilation pipe is movably connected, reacting for 15h at 180 ℃, filtering, washing with deionized water and absolute ethyl alcohol, and drying to obtain the aluminum-doped zinc oxide nano rod;

(2) adding deionized water, ethanol and vinyltrimethoxysilane into a reaction bottle, performing ultrasonic treatment for 10min to disperse uniformly, dropwise adding ammonia water, adjusting the pH value of the solution to 10, adding an aluminum-doped zinc oxide nano rod into the mixed solution, reacting for 3h at 55 ℃ with the mass ratio of the vinyltrimethoxysilane to the aluminum-doped zinc oxide nano rod being 150:100, cooling, filtering, washing with deionized water and absolute ethanol, and drying to obtain an aluminum-vinyl-doped zinc oxide nano rod;

(3) adding dilute sulfuric acid and an aluminum vinyl doped zinc oxide nano rod into a reaction bottle, stirring for 15min at 10 ℃, then respectively adding sodium nitrate and potassium permanganate, wherein the mass ratio of the aluminum vinyl doped zinc oxide nano rod to the sodium nitrate to the potassium permanganate is 100:50:325, continuing stirring at low temperature for 30min, then heating to 45 ℃ for reaction for 3h, then adding deionized water into the reaction bottle, heating to 75 ℃ for reaction for 5h, cooling, filtering, washing with deionized water, and drying to obtain a carboxylated aluminum doped zinc oxide nano rod;

(4) adding dilute sulfuric acid and p-toluenesulfonic acid into a reaction bottle, uniformly stirring to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, uniformly stirring to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylate doped zinc oxide nano rods into the mixed acid, wherein the mass ratio of the p-toluenesulfonic acid, the ammonium persulfate, the polyvinylpyrrolidone, the aniline and the aluminum carboxylate doped zinc oxide nano rods is 1.8:10.5:0.25:5:100, uniformly stirring, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring for reaction for 7 hours, centrifugally washing with deionized water and absolute ethyl alcohol, and drying to obtain the air-sensitive polyaniline material modified by the aluminum doped zinc oxide nano rods.

Example 3

(1) Adding deionized water, zinc nitrate, aluminum nitrate and sodium hydroxide into a reaction bottle in a mass ratio of 100:6.3:26, uniformly stirring, transferring the mixed solution into a reaction kettle, placing the reaction kettle in a hydrothermal device, the hydrothermal device comprises a main body, wherein the bottom of the main body is movably connected with a motor, the middle of the main body is movably connected with a partition plate, the top of the motor is movably connected with a flange platform, the top of the flange platform is movably connected with a fixed frame, the inside of the fixed frame is movably connected with a reaction kettle, the inside of the main body is movably connected with a ventilation pipe, the right side of the ventilation pipe is movably connected with an air inlet, the inside of the air inlet is movably connected with an air inlet fan, the left side of the ventilation pipe is movably connected, reacting for 18h at 170 ℃, filtering, washing with deionized water and absolute ethyl alcohol, and drying to obtain the aluminum-doped zinc oxide nano rod;

(2) adding deionized water, ethanol and vinyl trimethoxy silane into a reaction bottle, performing ultrasonic treatment for 5min to disperse uniformly, dripping ammonia water, adjusting the pH value of the solution to be 9, adding an aluminum-doped zinc oxide nano rod into the mixed solution, reacting for 4h at 50 ℃ with the mass ratio of the vinyl trimethoxy silane to the aluminum-doped zinc oxide nano rod being 130:100, cooling, filtering, washing with deionized water and absolute ethanol, and drying to obtain an aluminum vinyl-doped zinc oxide nano rod;

(3) adding dilute sulfuric acid and an aluminum vinyl doped zinc oxide nano rod into a reaction bottle, stirring for 15min at 5 ℃, then respectively adding sodium nitrate and potassium permanganate, wherein the mass ratio of the aluminum vinyl doped zinc oxide nano rod to the sodium nitrate to the potassium permanganate is 100:45:300, continuing stirring for 25min at low temperature, then heating to 40 ℃ for reaction for 4h, then adding deionized water into the reaction bottle, heating to 80 ℃ for reaction for 4h, cooling, filtering, washing with deionized water, and drying to obtain a carboxylated aluminum doped zinc oxide nano rod;

(4) adding dilute sulfuric acid and p-toluenesulfonic acid into a reaction bottle, uniformly stirring to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, uniformly stirring to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylate doped zinc oxide nano rods into the mixed acid, wherein the mass ratio of the p-toluenesulfonic acid, the ammonium persulfate, the polyvinylpyrrolidone, the aniline and the aluminum carboxylate doped zinc oxide nano rods is 1.6:10:0.2:4.5:100, uniformly stirring, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring for reaction for 8 hours, centrifugally washing with deionized water and absolute ethyl alcohol, and drying to obtain the air-sensitive polyaniline material modified by the aluminum doped zinc oxide nano rods.

Example 4

(1) Adding deionized water, zinc nitrate, aluminum nitrate and sodium hydroxide into a reaction bottle in a mass ratio of 100:7:31, uniformly stirring, transferring the mixed solution into a reaction kettle, placing the reaction kettle in a hydrothermal device, the hydrothermal device comprises a main body, wherein the bottom of the main body is movably connected with a motor, the middle of the main body is movably connected with a partition plate, the top of the motor is movably connected with a flange platform, the top of the flange platform is movably connected with a fixed frame, the inside of the fixed frame is movably connected with a reaction kettle, the inside of the main body is movably connected with a ventilation pipe, the right side of the ventilation pipe is movably connected with an air inlet, the inside of the air inlet is movably connected with an air inlet fan, the left side of the ventilation pipe is movably connected, reacting for 18h at 200 ℃, filtering, washing with deionized water and absolute ethyl alcohol, and drying to obtain the aluminum-doped zinc oxide nano rod;

(2) adding deionized water, ethanol and vinyl trimethoxy silane into a reaction bottle, performing ultrasonic treatment for 15min to disperse uniformly, dropwise adding ammonia water, adjusting the pH value of the solution to 10, adding an aluminum-doped zinc oxide nanorod into the mixed solution, reacting for 4h at 60 ℃ with the mass ratio of the vinyl trimethoxy silane to the aluminum-doped zinc oxide nanorod being 200:100, cooling, filtering, washing with deionized water and absolute ethanol, and drying to obtain an aluminum vinyl-doped zinc oxide nanorod;

(3) adding dilute sulfuric acid and an aluminum vinyl doped zinc oxide nano rod into a reaction bottle, stirring for 20min at 10 ℃, then respectively adding sodium nitrate and potassium permanganate, wherein the mass ratio of the aluminum vinyl doped zinc oxide nano rod to the sodium nitrate to the potassium permanganate is 100:60:400, continuing stirring for 40min at low temperature, then heating to 50 ℃ for reaction for 4h, then adding deionized water into the reaction bottle, heating to 80 ℃ for reaction for 6h, cooling, filtering, washing with deionized water, and drying to obtain a carboxylated aluminum doped zinc oxide nano rod;

(4) adding dilute sulfuric acid and p-toluenesulfonic acid into a reaction bottle, uniformly stirring to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, uniformly stirring to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylate doped zinc oxide nano rods into the mixed acid, wherein the mass ratio of the p-toluenesulfonic acid, the ammonium persulfate, the polyvinylpyrrolidone, the aniline and the aluminum carboxylate doped zinc oxide nano rods is 2:12:0.3:6:100, uniformly stirring, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring for reaction for 8 hours, centrifugally washing with deionized water and absolute ethyl alcohol, and drying to obtain the gas-sensitive material modified with the aluminum doped zinc oxide nano rods.

Comparative example 1

(1) Adding deionized water, zinc nitrate, aluminum nitrate and sodium hydroxide into a reaction bottle in a mass ratio of 100:5:20, uniformly stirring, transferring the mixed solution into a reaction kettle, placing the reaction kettle in a hydrothermal device, the hydrothermal device comprises a main body, wherein the bottom of the main body is movably connected with a motor, the middle of the main body is movably connected with a partition plate, the top of the motor is movably connected with a flange platform, the top of the flange platform is movably connected with a fixed frame, the inside of the fixed frame is movably connected with a reaction kettle, the inside of the main body is movably connected with a ventilation pipe, the right side of the ventilation pipe is movably connected with an air inlet, the inside of the air inlet is movably connected with an air inlet fan, the left side of the ventilation pipe is movably connected, reacting for 12h at 180 ℃, filtering, washing with deionized water and absolute ethyl alcohol, and drying to obtain the aluminum-doped zinc oxide nano rod;

(2) adding deionized water, ethanol and vinyltrimethoxysilane into a reaction bottle, performing ultrasonic treatment for 10min to disperse uniformly, dropwise adding ammonia water, adjusting the pH value of the solution to be 9, adding an aluminum-doped zinc oxide nano rod into the mixed solution, reacting for 3h at 50 ℃ with the mass ratio of the vinyltrimethoxysilane to the aluminum-doped zinc oxide nano rod being 70:100, cooling, filtering, washing with deionized water and absolute ethanol, and drying to obtain an aluminum-vinyl-doped zinc oxide nano rod;

(3) adding dilute sulfuric acid and an aluminum vinyl doped zinc oxide nano rod into a reaction bottle, stirring for 15min at 10 ℃, then respectively adding sodium nitrate and potassium permanganate, wherein the mass ratio of the aluminum vinyl doped zinc oxide nano rod to the sodium nitrate to the potassium permanganate is 100:50:300, continuing stirring at low temperature for 30min, then heating to 40 ℃ for reaction for 3h, then adding deionized water into the reaction bottle, heating to 70 ℃ for reaction for 5h, cooling, filtering, washing with deionized water, and drying to obtain a carboxylated aluminum doped zinc oxide nano rod;

(4) adding dilute sulfuric acid and p-toluenesulfonic acid into a reaction bottle, uniformly stirring to obtain mixed acid, taking one fifth volume of the mixed acid, adding ammonium persulfate into the mixed acid, uniformly stirring to obtain mixed solution, taking four fifths volume of the mixed acid, adding polyvinylpyrrolidone, aniline and aluminum carboxylate doped zinc oxide nano rods into the mixed acid, wherein the mass ratio of the p-toluenesulfonic acid, the ammonium persulfate, the polyvinylpyrrolidone, the aniline and the aluminum carboxylate doped zinc oxide nano rods is 1:7:0.1:3:100, uniformly stirring, dropwise adding the obtained solution into the mixed solution in an ice bath, stirring for reaction for 7 hours, centrifugally washing with deionized water and absolute ethyl alcohol, and drying to obtain the gas-sensitive material modified with the aluminum doped zinc oxide nano rods.

The method comprises the steps of taking glass as a substrate, carrying out photoetching on the surface of the glass to prepare a Pt electrode, mixing the gas-sensitive material of polyaniline modified by aluminum-doped zinc oxide nano-rods obtained in the embodiment and the comparative example with deionized water to obtain gas-sensitive slurry, uniformly coating a film on the surface of the substrate to form a film with the thickness of 20nm, drying, calcining at 450 ℃ for 2 hours to obtain an ethanol gas-sensitive element, irradiating the ethanol gas-sensitive element by using an F4T5/BLB type ultraviolet light-emitting diode as an ultraviolet light source with the power of 4W, introducing ethanol gas, testing the gas-sensitive performance of the ethanol by using a HW-30A type gas-sensitive testing system, wherein the sensitivity is the ratio of the resistance of the gas-sensitive element in the air to the resistance of the gas-sensitive element in.