Multifunctional pressure-gas sensor, method for manufacturing the same and use thereof

Abstract

The application relates to the field of multifunctional sensor preparation, in particular to a multifunctional pressure-gas sensor and a preparation method and application thereof. The preparation method comprises the following steps: copper nanowires and silver nanowires are dissolved in an alcohol solution, graphene oxide aqueous solution is added into the alcohol solution, ultrasonic stirring is carried out, and a graphene oxide-copper oxide nanowire-silver nanowire mixed solution is obtained; a reducing agent solution is added into the prepared mixed solution, and after hydrothermal self-assembly, freeze-drying is carried out; the freeze-dried product is subjected to cyclic-heat treatment in an air fryer, and a graphene oxide-copper oxide nanowire-silver nanowire aerogel is obtained. The application utilizes the efficient self-assembly of two-dimensional graphene and one-dimensional copper nanowires and silver nanowires to construct a unique three-dimensional conductive network, and utilizes the difference between the oxidation potentials of the two metal materials to in-situ generate copper oxide nanowires from the copper nanowires, realize specific recognition of ammonia gas, and manufacture a sensor to realize pressure detection and ammonia gas detection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of multifunctional sensor preparation, and particularly to a method for preparing three-dimensional porous composite rubber and a multifunctional pressure-gas sensor thereof by using an air fryer. BACKGROUND

[0002] With the development of science and technology, human health monitoring, intelligent robots, human-machine interface, etc. all need various sensing devices to detect pressure, temperature, humidity, gas, etc. signals. Building multifunctional sensors can integrate various sensing capabilities in limited space, becoming an effective way to realize the lightweight and small size requirements of electronic devices. Among the many sensing sources, mechanical force signals and gas signals provide a lot of practical information for human life. Among them, pressure can reflect the interaction between objects, so pressure detection is often used to simulate and record the movement of various parts of the human body. At the same time, efficient gas sensors are also an urgent demand in the field of intelligent electronics. Common volatile gases not only harm human health, but also interfere with the detection of other types of signals, and even cause equipment failure. Multifunctional pressure-gas sensors have good application prospects in multi-channel signal detection in complex scenarios, so they have been widely concerned.

[0003] Generally speaking, sensing materials are the core components of multifunctional pressure-gas sensors. Graphene has become an ideal material for building high-performance electronic sensors due to its large specific surface area and high electron mobility. Many single-channel sensors based on graphene have been verified, including gas, temperature, pressure, and biological sensors. As one of the common graphene materials, graphene oxide is easy to self-assemble into three-dimensional porous aerogels. Due to its excellent sensitivity and low weight, these three-dimensional graphene oxide aerogels are the first choice for low-power high-performance piezoresistive sensors. In addition, three-dimensional graphene oxide aerogels are considered to be the best gas-sensitive materials due to their electronic properties, porous structure, and large specific surface area. Three-dimensional graphene oxide composite aerogels have good pressure and gas detection applications and are a very promising multifunctional pressure-gas sensing material.

[0004] However, single graphene oxide as a sensing material has certain limitations whether it is applied to pressure detection or gas detection. When applied to pressure monitoring, the layered graphene nanosheets are prone to stacking, greatly reducing the reversibility of the sensing range; when applied to gas detection, the porous structure of graphene is conducive to the adsorption of gas, but the poor gas selectivity limits the specificity of the sensor. Metal and metal oxide nanomaterials have surface and interface effects, small size effects, quantum size effects, and macroscopic quantum tunneling effects, and are extremely sensitive to external stimuli. It is expected that modification of metal nanomaterials can better solve the above problems to realize the construction of high-performance multifunctional pressure-gas sensors. SUMMARY

[0005] The application aims to provide a method for preparing a three-dimensional porous composite rubber and a multifunctional pressure-gas sensor thereof by using an air fryer.

[0006] A method for preparing a pressure-gas sensor material, comprising the following steps:

[0007] (1) Copper nanowires and silver nanowires are dissolved in an alcohol solution, and a graphene oxide aqueous solution is added thereto, and ultrasonic stirring is performed to obtain a graphene oxide-copper oxide nanowire-silver nanowire mixed solution;

[0008] (2) A reducing agent solution is added to the mixed solution of step (1), and after hydrothermal self-assembly, freeze-drying is performed;

[0009] (3) The freeze-dried product of step (2) is subjected to cyclic-heat treatment in an air fryer to obtain a graphene oxide-copper oxide nanowire-silver nanowire aerogel;

[0010] The ratio of the copper nanowires, silver nanowires and alcohol solution is (10-100) mg:(10-70) mg:(10-30) ml; the concentration of the graphene oxide aqueous solution is 1-10 mg·ml -1 , and the volume ratio of the graphene oxide aqueous solution to the alcohol solution is 1:1.

[0011] In the above technical solution, further, the alcohol solution is at least one of an isopropyl alcohol-ethanol mixed solution, an isopropyl alcohol-acetone mixed solution and an isopropyl alcohol-cyclohexane mixed solution with a volume ratio of 1:1-4:1.

[0012] In the above technical solution, further, the temperature of the ultrasonic stirring is 5-15℃, the number of ultrasonic stirring is 3-5 times, and the time of each ultrasonic stirring and stirring is 10-20 min.

[0013] In the above technical solution, further, the reducing agent is at least one of sodium borohydride, hydrazine hydrate, glucose and ascorbic acid solution; and the mass fraction of the reducing agent solution is 10%-50%.

[0014] In the above technical solution, further, the temperature of the hydrothermal self-assembly is 130-200℃, and the time of the hydrothermal self-assembly is 4-12 h; the freeze-drying temperature is -50--60℃, and the freeze-drying time is 12-24 h.

[0015] In the above technical solution, further, the cyclic-heat treatment temperature of the air fryer is 150-250℃, and the time is 2-12 h; and the heating mode of the air fryer is infrared combined with moving air energy, and the air speed is 0.5-2.3 m·s -1The temperature control range is 0-250 DEG C, and the rated power is 250-1250 W.

[0016] In the technical solution, the diameter of the copper nanowire and the silver nanowire is 100-300 nm, and the length-diameter ratio is 70-500.

[0017] Preferably, the preparation of the copper nanowire comprises the following steps:

[0018] The cuprous chloride and the ammonium chloride are mixed in a substance amount ratio of 10:1-20:1, 30-50 ml of ethylene glycol is added, and ultrasonic treatment is performed for 10-30 min; 5-10 mmol of oleylamine is added drop by drop under stirring, and heating is performed to 100-120 DEG C for 15-25 min; the heating rate is controlled to be 5-15 DEG C / min -1 The reaction temperature is increased to 180-220 DEG C for 20 min; after the reaction is completed, cold water is quickly added to quench the reaction, and a red-brown solution is obtained; 10-20 ml of n-hexane is added to the solution, and after the solution is separated, the lower layer red-brown solution is taken out and centrifuged, and the copper nanowire is obtained by washing the red-brown precipitate with a n-hexane-isopropyl alcohol mixed solution for several times;

[0019] Preferably, the preparation of the silver nanowire comprises the following steps:

[0020] The ethylene glycol and the glycerol are mixed and stirred uniformly in a volume ratio of 3:1-5:1, 0.1-0.5 g of polyvinylpyrrolidone is added, and stirring is performed for 10-30 min under the condition of a 50-80 DEG C water bath; silver nitrate ethylene glycol solution is added drop by drop under stirring, and stirring is continuously performed for 1-3 h; 0.01-0.06 mmol of copper chloride dihydrate solution 0.5-1.0 ml is added drop by drop to the mixed solution, ultrasonic stirring is performed for 30 min, the mixed solution is loaded into a polytetrafluoroethylene-lined reaction kettle, and oven heating is performed at 100-180 DEG C for 2-8 h; after the reaction is completed, cold water is quickly added to quench the reaction, and a silver-white solution is obtained; ethanol is added to the solution, and centrifugation is performed to obtain a silver-white precipitate; the silver nanowire is obtained by washing the silver-white precipitate with an isopropyl alcohol-ethanol mixed solution for several times.

[0021] The present application provides a pressure-gas sensor prepared from the aerogel obtained by the preparation method; preferably, the surface of the aerogel is coated with polydimethylsiloxane, and porous sensing rubber is obtained after drying; electrodes and wires are fixed on both sides of the rubber to obtain the pressure-gas sensor.

[0022] In the technical solution, the pressure-gas sensor is applied to ammonia detection and pressure detection.

[0023] In the technical solution, further, the ammonia concentration is 10-2000 ppm, the sensor compression deformation range is 0-50%, and the stress change range is 0-1600 kpa.

[0024] Compared with the prior art, the application has the following beneficial effects:

[0025] The application adopts a hydrothermal self-assembly and in-situ oxidation method to prepare a graphene oxide-copper oxide nanowire-silver nanowire aerogel and make a sensor. The two-dimensional graphene and one-dimensional copper nanowire and silver nanowire are efficiently self-assembled to construct a unique three-dimensional conductive network, and the difference between the oxidation potentials of the two metal materials is ingeniously used to make the copper nanowire generate copper oxide nanowire in-situ, so that the specific identification of ammonia gas is realized.

[0026] When the sensor is stimulated by pressure, the internal three-dimensional network pores become smaller, the resistance is greatly reduced, and the detection of pressure can be realized. In the compression deformation range of 0-50%, the pressure detection of 0-1600 kpa can be completed, and the compression-release cycle can be 5-3000 times. When the sensor is placed in a target atmosphere, a large number of electron-donating gas adsorption inhibits the generation of hole carriers, so that the resistance is greatly increased. In the ammonia atmosphere of 500 ppm, a resistance response of more than 50% can be realized, and the performance remains stable in the cycle test of 5-3000 times. The sensor of the application can adjust the sensitivity, response time and other sensing performances by changing the content of different components in the system.

[0027] In addition, the application ingeniously uses the air fryer in the heating and calcination process to realize the uniform and rapid synthesis of copper oxide at a lower heating temperature, effectively increases the performance stability and efficient synthesis of the sensor, effectively reduces the production cost, and the multifunctional pressure-gas sensor prepared by the application can benefit from the unique three-dimensional structure of the graphene oxide-copper oxide nanowire-silver nanowire and the specific recognition site provided by the copper oxide for ammonia gas, as well as the protection of the polydimethylsiloxane layer, and can efficiently sense pressure and gas, maintain good stability and high sensitivity in multiple compression-release cycles, realize the specific identification of ammonia gas under room temperature conditions, and has broad application prospects in the fields of health monitoring, innovative medicine, intelligent wearable devices and intelligent robots and other small flexible electronic devices. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The resistance change of the sample prepared in Example 1 under different compression deformations.

[0029] Figure 2 The resistance change of the sample prepared in Example 1 in different concentrations of ammonia vapor.

[0030] Figure 3Scanning electron microscope image of the graphene oxide-copper oxide nanowire-silver nanowire aerogel described in Example 1.

[0031] Figure 4 Scanning electron microscope image of the graphene oxide-copper oxide nanowire-silver nanowire aerogel described in Comparative Example 1.

[0032] Figure 5 Scanning electron microscope image of the graphene oxide-copper oxide nanowire-silver nanowire aerogel described in Comparative Example 2.

[0033] Figure 6 Scanning electron microscope image of the graphene oxide-copper oxide nanowire-silver nanowire aerogel described in Comparative Example 3. DETAILED DESCRIPTION

[0034] The application is further described below in connection with specific embodiments, but in no way limits the application.

[0035] The preparation steps of copper nanowires are as follows:

[0036] Mix cuprous chloride and ammonium chloride in a substance amount ratio of 10:1 to 20:1, add 30 to 50 ml of ethylene glycol, and ultrasonically treat for 10 to 30 min. Add 5 to 10 mmol of oleylamine drop by drop under stirring. Then heat to 80 to 120°C and keep for 10 to 30 min. Control the temperature rising rate at 5 to 15°C·min -1 Increase the reaction temperature to 180 to 220°C and keep for 20 min. After the reaction is completed, quench with cold water quickly to obtain a red-brown solution. Add 10 to 20 ml of n-hexane to the solution, and after the solution is layered, centrifuge the lower red-brown solution to obtain a red-brown precipitate. Then wash the copper nanowires with a n-hexane-isopropyl alcohol mixture several times and store at a temperature of 15 to 25°C.

[0037] The preparation steps of silver nanowires are as follows:

[0038] Mix ethylene glycol and glycerol in a volume ratio of 3:1 to 5:1 under stirring until uniform, and add polyvinylpyrrolidone thereto. Stir for 10 to 30 min under the condition of heating in a water bath at 50 to 70°C until uniform and transparent. Add silver nitrate ethylene glycol solution drop by drop under stirring, and continue to stir for 1 to 3 h. Then add 0.01 to 0.06 mmol of copper chloride dihydrate solution 0.5 to 1.0 ml drop by drop to the mixture, ultrasonically treat and stir for 30 min, load into a polytetrafluoroethylene-lined reaction kettle, and heat in an oven at 100 to 180°C for 2 to 8 h. After the reaction is completed, quench with cold water quickly to obtain a silver-white solution. Add a certain amount of ethanol solution to the solution, and centrifuge at 5000 rpm·min -1The silver nanowires were obtained by centrifugation under the condition of 5000 rpm·min

[0039] The application provides a method for preparing a three-dimensional porous composite rubber and a multifunctional pressure-gas sensor thereof by using an air fryer, which comprises the following steps:

[0040] A certain amount of copper nanowires and silver nanowires were dissolved in an isopropanol-ethanol mixed solution, and then a certain amount of graphene oxide aqueous solution was added dropwise. After multiple ultrasonic and stirring, a brown graphene oxide-copper oxide nanowire-silver nanowire mixed solution was obtained. A small amount of reducing agent was added dropwise into the mixed solution, and the reaction kettle with a polytetrafluoroethylene lining was loaded. The graphene oxide-copper oxide nanowire-silver nanowire aerogel was obtained by hydrothermal self-assembly under a certain temperature and time, and then freeze-drying and cyclic-heat treatment in an air fryer. Then, the aerogel was coated with polydimethylsiloxane and dried at a certain temperature to obtain a porous sensing rubber. Finally, a copper foil electrode coated with silver nanowires and a wire were fixed on both sides of the rubber by using epoxy resin, and a multifunctional pressure-gas sensor was obtained.

[0041] The preferred embodiments of the application are described in detail below.

[0042] Example 1 provides a method for preparing a three-dimensional porous composite rubber and a multifunctional pressure-gas sensor thereof by using an air fryer, which comprises the following steps:

[0043] First, the copper nanowires were prepared: 2 mmol of cuprous chloride and 0.4 mmol of ammonium chloride were placed in a 100 ml round-bottom flask, 30 ml of ethylene glycol was added, and then ultrasonic stirring was performed until the mixture was uniform. Then, 8 mmol of oleylamine was added dropwise under stirring. Then, the reaction temperature was increased to 110℃, and the temperature was maintained for 20 min to fully form the copper amine complex. Finally, the temperature was increased at a rate of 10℃·min -1 The reaction temperature was heated to 200℃ and maintained for 20 min. After the reaction was completed, the solution was quickly quenched with cold water to obtain a red-brown solution. 10-20 ml of n-hexane was added to the solution, and after the solution was layered, the lower layer of the red-brown solution was taken and centrifuged at 5000 rpm·min -1 for 5 min to obtain a red-brown precipitate. Then, the precipitate was washed several times with a mixture of n-hexane and isopropanol in a volume ratio of 1:1 to obtain copper nanowires.

[0044] The silver nanowires were prepared: 30 ml of ethylene glycol and 10 ml of glycerol were stirred uniformly, and then 0.4 g of polyvinylpyrrolidone with a molecular weight of 1300000 was added. The mixture was heated in a 70℃ water bath for 10-30 min until it became uniform and transparent. Under stirring, 0.05 g·ml -1A solution of silver nitrate in ethylene glycol 10 ml was prepared and stirred for 1 h. To the mixture, a solution of copper chloride dihydrate 0.01-0.06 mmol in 0.5-1.0 ml was added dropwise, and ultrasonic stirring was performed for 30 min. The mixture was transferred into a reaction kettle lined with polytetrafluoroethylene and heated in an oven at 130 °C for 3 h. After the reaction was completed, the mixture was rapidly quenched with cold water to obtain a silver-white solution. Ethanol was added to the solution to a total volume of 40 ml, and the mixture was centrifuged at 5000 rpm·min -1 for 5 min to obtain a silver-white precipitate. The precipitate was then washed several times with a mixture of isopropanol and ethanol to obtain silver nanowires.

[0045] The silver nanowires and copper nanowires prepared above were dispersed in a mixed alcohol solution. 87.5 mg of copper nanowires were dissolved in 10 ml of a mixture of isopropanol and ethanol, and then 37.5 mg of silver nanowires were dissolved in 10 ml of a mixture of isopropanol and ethanol. The two solutions were stirred uniformly, and then 20 ml of a 2.5 mg·ml -1 of a graphene oxide aqueous solution was added dropwise. Ultrasonic stirring was performed for 20 min, and after 3 cycles, a 45% sodium borohydride solution was added dropwise. The mixture was transferred into a reaction kettle lined with polytetrafluoroethylene and heated in an oven at 180 °C for 4 h. The product was removed, freeze-dried at -60 °C for 12 h, and then calcined in an air fryer at 225 °C for 4 h. The product was immersed in pre-solidified polydimethylsiloxane, and after being removed, it was allowed to stand for 1 h and then dried at 90 °C for 1 h. Finally, a silver nanowire-coated copper foil electrode and a lead wire were fixed on both sides of the rubber using an epoxy resin, and a multifunctional pressure-gas sensor was obtained.

[0046] Under a compression deformation of 0-50%, the resistance change rate of the sensor was 0.96, and the response time was 66 ms; when the sensing rubber was placed in an ammonia gas environment with a concentration of 500 ppm, the resistance change rate of the aerogel was 51.3%, and the response-recovery time was 272 s.

[0047] Figure 1 The resistance change rate of the sensor in the compression range of 0-50% had strong cycle stability in the process of repeated compression and release;

[0048] Figure 2 The resistance change rate of the sensor in the ammonia gas concentration range of 50-700 ppm exhibited good recyclability and linearity in the process of repeated gas charging and discharging.

[0049] The graphene oxide-copper oxide nanowire-silver nanowire three-dimensional aerogel was characterized by scanning electron microscopy, and the results are shown in Figure 3 Fig. 1. As can be seen from the figure, the silver nanowires have a small diameter and a smooth surface; the copper oxide nanowires have a larger diameter and are formed by connecting smaller copper oxide nanoparticles; and the graphene oxide has a two-dimensional sheet structure. The copper oxide nanowires and silver nanowires are intertwined between the graphene oxide nanosheets to form a unique three-dimensional porous structure.

[0050] The application constructs a three-dimensional porous aerogel composed of copper oxide nanowires, silver nanowires and graphene oxide, and strengthens the mechanical strength of the aerogel through a polydimethylsiloxane coating. When the aerogel is subjected to pressure stimulation, the accumulation of the porous structure becomes compact, resulting in more electronic paths and a lower resistance. When the aerogel is in an ammonia environment, the surface carrier concentration is inhibited, and the resistance increases. The application, based on the self-assembly of graphene oxide and one-dimensional copper oxide and silver nanowires, and the difference in the oxidation potential between copper and silver, prepares a porous aerogel with a unique three-dimensional structure for application in a multifunctional pressure-gas sensor. By adjusting the content of each component, the micro-morphology of the aerogel and the number of active centers can be changed, resulting in a large difference in sensitivity and response time.

[0051] Comparative Example 1 provides a method for preparing a three-dimensional porous composite rubber and a multifunctional pressure-gas sensor thereof using an air fryer, which is basically the same as in Example 1, except that the mass of the prepared copper nanowires is 100 mg, and the mass of the silver nanowires is 25 mg.

[0052] Under a compression deformation of 0-50%, the resistance change rate of the sensor is 0.86, and the response time is 88 ms. When the aerogel is in a 500 ppm ammonia environment, the resistance change rate of the aerogel is 48.4%, and the response-recovery time is 305 s. The micro-characterization is shown in Figure 4 The surface of the copper oxide nanowires has smaller protrusions, but the components are uniformly distributed.

[0053] Comparative Example 1 can be seen that the reduction of the content of silver nanowires makes the oxidation effect of copper nanowires worse, and hinders effective electron transmission. The sensitivity and response time of the pressure-sensitive sensor are greatly affected, and the gas-sensitive sensitivity does not decrease significantly, but the response time increases significantly.

[0054] Comparative Example 2 provides a method for preparing a three-dimensional porous composite rubber and a multifunctional pressure-gas sensor thereof using an air fryer, which is basically the same as in Example 1, except that the mass of the prepared copper nanowires is 75 mg, and the mass of the silver nanowires is 50 mg.

[0055] Under a compression deformation of 0-50%, the resistance change rate of the sensor is 0.89, and the response time is 60 ms. When the aerogel is in a 500 ppm ammonia environment, the resistance change rate of the aerogel is 33.6%, and the response-recovery time is 253 s. The micro-characterization is shown in Figure 5 The small particles constituting the copper oxide nanowires gradually disintegrate, but the components are uniformly distributed.

[0056] Comparative Example 1, it can be seen that the increase of silver nanowire content and the decrease of copper nanowire content make the oxidation of copper nanowire become more severe. A large amount of silver nanowire ensures the effective transmission of electrons, and the pressure- and gas-sensitive response time is greatly reduced, but a large amount of nanowire-shaped copper oxide becomes granular, which destroys the original three-dimensional structure, accompanied by the decrease of the content of copper oxide itself, which makes the pressure- and gas-sensitive sensitivity have a greater loss.

[0057] Comparative Example 3 provides a method for preparing a three-dimensional porous composite rubber and a multifunctional pressure-gas sensor thereof by using an air fryer, which is basically the same as that in Example 1, except that the mass of the prepared copper nanowire is 62.5 mg and the mass of the silver nanowire is 62.5 mg.

[0058] Under 0-50% compression deformation, the resistance change rate of the sensor is 0.79, and the response time is 57 ms; when the aerogel is in an ammonia gas environment of 500 ppm, the resistance change rate of the aerogel is 15.6%, and the response-recovery time is 198 s. The microcharacterization thereof is shown in FIG. 6, and it can be seen that the copper oxide exists in the form of particles between the silver nanowires and the graphene oxide, and the components are uniformly distributed. Figure 6

[0059] Comparative Example 1, the aerogel has a large structural change. The pressure- and gas-sensitive response time is further reduced, and the sensitivity also has a greater loss.

[0060] For any person skilled in the art, many possible changes and modifications or equivalent embodiments of the technical solutions of the present application can be made to the technical content disclosed above without departing from the scope of the technical solutions of the present application. Therefore, any simple modification, equivalent change and modification made to the above examples according to the technical essence of the present application, which does not deviate from the content of the technical solutions of the present application, should still belong to the scope of protection of the technical solutions of the present application.​

Claims

1. A method for the production of a pressure-gas sensor material, characterized in that It comprises the following steps: (1) Copper nanowires and silver nanowires are dissolved in an alcohol solution, and a graphene oxide aqueous solution is added thereto, and ultrasonic stirring is performed to obtain a graphene oxide-copper oxide nanowire-silver nanowire mixture solution; (2) A reducing agent solution is added to the mixture solution of step (1), and after hydrothermal self-assembly, freeze-drying is performed; (3) The freeze-dried product of step (2) is subjected to cycle-heat treatment in an air fryer to obtain a graphene oxide-copper oxide nanowire-silver nanowire aerogel. The ratio of the copper nanowire, silver nanowire, and alcohol solution is 10-100 mg:10-70 mg:10-30 ml; the concentration of the graphene oxide aqueous solution is 1-10 mg ml -1 , and the volume ratio of the graphene oxide aqueous solution and alcohol solution is 1:

1.

2. The production method according to claim 1, characterized by, The alcohol solution is at least one of an isopropyl alcohol-ethanol mixture, an isopropyl alcohol-acetone mixture, and an isopropyl alcohol-cyclohexane mixture in a volume ratio of 1:1 to 4:

1.

3. The preparation method according to claim 1, characterized in that, The temperature of the ultrasonic stirring is 5-15°C, and the number of ultrasonic stirring is 3-5 times, and the time of each ultrasonic stirring and stirring is 10-20 min.

4. The method of claim 1, wherein, The reducing agent is at least one of sodium borohydride, hydrazine hydrate, glucose, and ascorbic acid solution; and the mass fraction of the reducing agent solution is 10%-50%.

5. The preparation method according to claim 1, characterized in that, The temperature of the hydrothermal self-assembly is 130-200°C, and the time of the hydrothermal self-assembly is 4-12 h; the freeze-drying temperature is -50 to -60°C, and the freeze-drying time is 12-24 h.

6. The method of claim 1, wherein, The cycle-heat treatment temperature of the air fryer is 150-250°C, and the time is 2-12 h.

7. The preparation method according to claim 1, characterized in that, The diameter of the copper nanowires and silver nanowires is 100-300 nm, and the aspect ratio is 70-500. The preparation of the copper nanowires comprises the following steps: Mix cuprous chloride and ammonium chloride in a molar ratio of 10:1 to 20:1, add 30 to 50 ml of ethylene glycol, ultrasonic for 10 to 30 min, add 5 to 10 mmol of oleylamine drop by drop under stirring, heat to 100 to 120 DEG C and keep for 15 to 25 min; control the temperature rising rate at 5 to 15 DEG C / min -1 Increase the reaction temperature to 180 to 220 DEG C and keep for 20 min; after the reaction is completed, quench rapidly with cold water to obtain a red-brown solution; After the solution is layered, the lower red-brown solution is taken out and centrifuged to obtain a red-brown precipitate, which is washed several times with an isopropyl alcohol-n-hexane mixture to obtain copper nanowires. The preparation of the silver nanowires comprises the following steps: Ethylene glycol and glycerol are mixed and stirred uniformly in a volume ratio of 3:1 to 5:1, 0.1-0.5 g of polyvinylpyrrolidone is added thereto, and stirring is performed at 50-80°C under water bath heating conditions for 10-30 min until uniform transparency is achieved, silver nitrate ethylene glycol solution is added dropwise under stirring, and stirring is continued for 1-3 h, 0.01-0.06 mmol of copper chloride dihydrate solution 0.5-1.0 ml is added dropwise to the mixture, ultrasonic stirring is performed for 30 min, the mixture is loaded into a polytetrafluoroethylene-lined reaction kettle, and the kettle is heated in an oven at 100-180°C for 2-8 h, after the reaction is completed, the mixture is quickly quenched with cold water to obtain a silver-white solution, ethanol is added to the solution, and centrifugation is performed to obtain a silver-white precipitate, which is washed several times with an isopropyl alcohol-ethanol mixture to obtain silver nanowires.

8. A pressure-gas sensor, characterized by The aerogel is prepared by the preparation method of any one of claims 1-7; the surface of the aerogel is coated with polydimethylsiloxane, and after drying, a porous sensing rubber is obtained, electrodes and wires are fixed on both sides of the rubber to obtain a pressure-gas sensor.

9. The pressure-gas sensor of claim 8 is applied in ammonia gas detection and pressure detection.

10. Use according to claim 9, characterized in that, The ammonia gas concentration is 10-2000 ppm, and the sensor compression deformation range is 0-50%; the applied stress change range is 0-1600 kpa.

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