Preparation and use method of MOF-derived AuRu-In2O3 gas-sensitive material with UV-assisted sensitization

Abstract

The invention discloses a preparation and use method of a UV-assisted sensitization MOF-derived AuRu-In2O3 gas-sensitive material, the preparation method of the gas-sensitive material comprises the following steps: taking a metal organic framework formed by In-BTC / DOBDC as a matrix, calcining to obtain pure indium oxide, then modifying Au and Ru on the surface of indium oxide by using an in-situ oxidation-reduction technology and regulating and controlling parameters such as a loading ratio and reaction time, and finally preparing the gas-sensitive material. And the AuRu-In2O3 gas sensitive material is obtained. The gas sensitive element prepared from the AuRu-In2O3 gas sensitive material overcomes the problems of high working temperature, high detection line, low sensitivity, poor selectivity and the like of the existing triethylamine gas sensor. Meanwhile, the irradiation of the ultraviolet lamp in the gas detection process not only improves the gas-sensitive property of the sensor for detecting triethylamine at low temperature, but also enables the gas sensor to realize high-performance detection of triethylamine at room temperature, and particularly enables the sensor to be more suitable for detecting triethylamine in a relatively humid room temperature environment. The AuRu-In2O3 gas-sensitive material prepared by the preparation method disclosed by the invention is excellent in performance and has an important application value in the aspect of detecting triethylamine gas.

Description

Technical Field

[0001] The present invention belongs to the technical field of oxide semiconductor gas sensors, and specifically relates to a UV-assisted MOF-derived AuRu-In 2 O 3 Preparation and use of gas-sensitive materials. Background Art

[0002] Triethylamine (TEA) is an important chemical raw material, mainly used as a catalyst, preservative, synthetic dye, etc. TEA has a strong fishy smell and is a volatile organic compound (VOC). Its concentration is usually used as a chemical indicator to test the quality of marine organisms. However, high concentrations of TEA can seriously cause discomfort and harm to human health, such as respiratory irritation, vomiting, headaches, and even death. At the same time, when exposed to open flames, high temperatures, and strong oxidants, its flammability and explosiveness pose a threat to environmental safety. The National Institute for Occupational Safety and Health recommends that the safe upper limit of TEA concentration should be 10ppm, while the threshold value determined by the American Conference of Governmental Industrial Hygienists (ACGIH) is 1ppm. Therefore, it is urgent to develop TEA gas sensors with high selectivity, low detection limits, fast detection speed, and low operating temperature.

[0003] At present, the methods for detecting TEA include gas chromatography, catalytic combustion gas sensor, electrochemical sensor, photoionization detector, photoionization gas sensor, etc. These methods can detect a certain concentration of TEA, but there are some disadvantages, such as long detection time, high detection cost, and complicated operation process. Metal oxide semiconductor gas sensors have attracted extensive attention from scientific researchers due to their advantages such as low manufacturing cost, high sensitivity, and ability to quickly and accurately detect target gases.

[0004] Typical n-type semiconductor metal oxide indium oxide (In 2 O 3 ), has attracted wide attention in the field of gas detection due to its wide band gap (3.55-3.75 eV), low resistivity, excellent thermal stability, and excellent physical and chemical properties. Although single indium oxide material responds to TEA gas, it still has problems such as high operating temperature, low selectivity between gases, and high detection limit, which hinders the implementation of practical applications. Summary of the invention

[0005] Aiming at the shortcomings of the current indium oxide-based triethylamine gas sensor, such as high operating temperature, high detection limit, low sensitivity, poor moisture resistance, and difficulty in recovering room temperature detection, the present invention provides a UV-assisted MOF-derived AuRu-In 2 O 3Preparation and use of gas-sensitive materials. The gas-sensitive material obtained by the preparation method is suitable for low-temperature and room-temperature detection of triethylamine gas. The preparation of the gas-sensitive material uses a metal organic framework (MOF) formed by In-BTC / DOBDC as a matrix, and pure indium oxide is obtained after calcination. Subsequently, Au and Ru are modified on the surface of indium oxide by in-situ redox technology to adjust parameters such as loading ratio and reaction time, thereby obtaining AuRu-In 2 O 3 Gas-sensitive material. The gas-sensitive element is made through subsequent coating and welding processes. The obtained gas-sensitive element overcomes the problems of high operating temperature, high detection limit, low sensitivity, poor selectivity, etc. of the existing triethylamine gas sensor. At the same time, the irradiation of ultraviolet light (UV) during the gas detection process not only improves the gas-sensitive performance of the sensor in detecting triethylamine at low temperature, but also enables the gas sensor to achieve high-performance detection of triethylamine at room temperature, especially making the sensor more suitable for detecting triethylamine in a relatively humid room temperature environment.

[0006] The present invention adopts the following technical scheme: a UV-assisted MOF-derived AuRu-In 2 O 3 A method for preparing a gas-sensitive material, characterized in that the method comprises the following steps: Step 1: Dissolve 0.8-1.5 mmol indium nitrate in 20-40 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 0.5-1.5 mmol of terephthalic acid and 0.5-1.5 mmol of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 20-40 minutes at a stirring rate of 800-1000 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:0.5~1.5:0.5~1.5; Step 3: placing the mixed solution in an oven and reacting it at 100-140°C for 0.5-1.5 h. After the reaction, cooling the mixed solution for 10-15 h, centrifuging it, taking the precipitate and washing it alternately with deionized water and anhydrous ethanol for 5-7 times, and then placing the washed precipitate in an oven at 60-80°C and drying it for 5-10 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 400-600° C. for 2-3 hours at a heating rate of 1-3° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10-30 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, perform ultrasonication for 5-10 min, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: Prepare RuCl at a concentration of 0.5 mg / mL at room temperature. 3 Solution, HAuCl at a concentration of 20 mg / mL 4 ·4H 2 O solution, NaBH at a concentration of 0.05 mmol / mL 4 Solution; Step 7: Take 3-10 μL of the above HAuCl 4 ·4H 2 HO solution and 5-15 μL of RuCl 3 The solution was slowly added to the indium oxide suspension in step 5, and magnetic stirring was performed for 10-20 min; then 40-60 μL of the above NaBH was slowly added. 4 The solution is stirred magnetically for 10-30 min at a stirring rate of 800-1000 rpm; then it is allowed to stand for 3-5 h, after which it is centrifuged, the precipitate is taken and washed alternately with ethanol and deionized water for 5-7 times, and then the precipitate is placed in an oven and dried for 5-10 h to obtain the metal organic framework-derived AuRu-In 2 O 3 Gas sensitive materials.

[0007] Furthermore, the present invention provides a UV-assisted MOF-derived AuRu-In 2 O 3 The method for using the gas-sensitive material is characterized in that the AuRu-In 2 O 3 The gas-sensitive material is obtained by the preparation method as described above, and its use method comprises the following steps: Step 1) Place the AuRu-In 2 O 3 The gas-sensitive material is used as the gas-sensitive material of the gas-sensitive element to make the indirectly heated gas-sensitive element.

[0008] Step 2) Connect the above-mentioned gas sensor to the circuit, load the working voltage at both ends of the resistance wire, so that the resistance wire heats up and generates heat, so that the gas sensor obtains different working temperatures; two annular metal electrodes connect the detection resistor of the gas sensor with a load resistor in series through their connection terminals to form a series resistance circuit, and the test voltage V is supplied to both ends of the series resistance circuit. c , the voltage across the load resistor is the output voltage V out , the resistance value of the detection resistor R 1 =V c / V out(1-R 0 ), R 0 is the resistance value of the load resistor; at the test voltage V c Under the condition of no change, the resistance value of the detection resistor changes with the temperature in the environment and the type and concentration of the target gas; Step 3) Place the gas sensor in a 1L air bottle and wait for the resistance value of the gas sensor's detection resistor to stabilize at the operating temperature; then place the gas sensor in a 1L glass container filled with the target gas and wait for the resistance value of its detection resistor to stabilize. Record the resistance value at this time as R g ; Step 4) Transfer the gas sensor to a 1L quartz glass bottle that is transparent to ultraviolet light, turn on the ultraviolet lamp with a wavelength of 300-400 nm, and place the quartz glass bottle directly opposite the ultraviolet lamp with a horizontal distance of 5-10 cm to promote the desorption of gas molecules on the surface of the gas-sensitive material until the resistance value of the detection resistor of the gas-sensitive material is stable. Record the resistance value of the detection resistor of the gas sensor after desorption as R UV , turn off the UV lamp; Step 5) Use the obtained R UV , R g , calculate the sensitivity S=R UV / R g ; According to the sensitivity of target gas with different concentrations, draw the correlation curve between the concentration and sensitivity of target gas; Step 6) Place the gas sensor in a 1L glass container filled with a target gas of unknown concentration, wait for the resistance value of its detection resistor to stabilize, and record the resistance value at this time; then repeat the operation of step 4) to record the resistance value of the detection resistor of the gas sensor after desorption; based on the above two resistance values, obtain the sensitivity value of the target gas of unknown concentration; substitute the sensitivity value into the correlation curve in step 5) to obtain the concentration value of the target gas of unknown concentration.

[0009] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention innovatively uses N-N-dimethylformamide as solvent, indium nitrate, terephthalic acid and trimesic acid as precursors, and synthesizes the indium oxide metal organic framework In-BTC / DOBDC in liquid phase at room temperature. After annealing, porous clustered indium oxide is obtained. Using this as the matrix, Au and Ru are modified on the surface using in-situ redox technology. The resulting product is AuRu-In 2 O 3The gas-sensitive material and the gas-sensitive element prepared from the gas-sensitive material have a high response (350-750) to 50ppm triethylamine at a relatively low working temperature (175°C), a detection limit as low as 10ppb, and a response time of only 1 s. The gas-sensitive element obtained by the method of the present invention has a wide range of application prospects in the field of low-temperature detection of trace triethylamine gas.

[0010] (2) In the process of gas detection, the present invention uses an ultraviolet lamp device to irradiate the gas sensor when it recovers, shortening the recovery time of the gas sensor for detecting triethylamine at low temperature (175°C) and improving the response (835). At the same time, high-performance detection of triethylamine at room temperature is achieved. Specifically, under the irradiation of ultraviolet light, the baseline resistance of the gas sensor is greatly improved, thereby greatly improving the response to 50 ppm triethylamine (250), prompting the rapid desorption of triethylamine on the sensor, so that the sensor can recover quickly in the air. More importantly, the addition of the ultraviolet lamp device overcomes the problem of poor moisture resistance of the previous triethylamine gas sensor, and even makes the sensor more suitable for detecting triethylamine in a relatively humid environment (80 RH%), with a response of up to 2332. It has broad application prospects in detecting triethylamine gas in a humid room temperature environment.

[0011] (3) AuRu-In prepared by the present invention 2 O 3 The gas-sensitive material has a simple preparation process, a short cycle, low cost, high selectivity for triethylamine gas, and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The figure shows the structure of the indirectly heated gas sensor; wherein A is a resistance wire, B is an insulating ceramic tube, C is a No. 1 annular metal electrode, D is a No. 2 annular metal electrode, and E is a gas-sensitive material coating; 1 and 6 are connecting pins connected to both ends of the resistance wire, 2 and 3 are connecting pins connected to both ends of the No. 1 metal electrode, and 4 and 5 are connecting pins connected to both ends of the No. 2 metal electrode.

[0013] Figure 2 The figure shows the packaging state of the indirectly heated gas sensor.

[0014] Figure 3 The indium oxide (In 2 O 3 ) Scanning electron microscope image of the gas-sensitive material at 20k magnification.

[0015] Figure 4 The AuRu-In obtained in Example 2 of the present invention is shown. 2 O 3 Scanning electron microscope image of gas-sensitive material at 20k magnification.

[0016] Figure 5 The graphs show the response of the gas sensing elements prepared from the gas sensing materials of Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3 of the present invention respectively as a function of the operating temperature.

[0017] Figure 6 The graph shows the response of the gas sensor prepared from the indium oxide gas-sensitive material in Comparative Example 1 of the present invention to 50 ppm of triethylamine and 100 ppm of other different gases at 175°C.

[0018] Figure 7 The graph is a response test of the gas sensor prepared from the gas-sensitive material of Example 2 to 50 ppm of triethylamine and 100 ppm of other different gases at the optimal working temperature of 175°C.

[0019] Figure 8 The figure shows the change of sensitivity of the gas sensing elements prepared from the gas sensing materials in Comparative Examples 1-3 and Examples 1-3 of the present invention with the concentration of triethylamine in the range of 10 ppb-50 ppm.

[0020] Fig. 9 The figure shows the change of sensitivity of the gas sensing elements prepared from the gas sensing materials in Comparative Examples 1-3 and Examples 1-3 of the present invention with the concentration range of 10 ppb-1 ppm triethylamine as a function of concentration.

[0021] Fig.10 The figure shows a curve of the sensitivity of the gas-sensitive element prepared by the gas-sensitive material of Example 2 of the present invention at the optimal working temperature of 175° C. versus concentration.

[0022] Fig.11 The figure shows a comparison of the recovery time of the gas-sensitive element prepared by the gas-sensitive material of Example 2 of the present invention in air and under ultraviolet light irradiation; wherein the gray shaded part is the data under ultraviolet light irradiation.

[0023] Fig.12 Shown is a test graph of the response of the gas-sensitive element prepared from the gas-sensitive material of Example 2 of the present invention to 50 ppm triethylamine and 100 ppm other gases under recovery under the irradiation of an ultraviolet lamp at room temperature.

[0024] Fig.13 The figure shows the sensitivity curve of the gas sensor prepared by the gas-sensitive material of Example 2 of the present invention at room temperature under the recovery of ultraviolet light with different concentrations of triethylamine.

[0025] Fig.14The figure shows a line graph showing the change in sensitivity of the gas-sensitive element prepared from the gas-sensitive material of Example 2 of the present invention with the concentration of triethylamine when the gas-sensitive element is restored by ultraviolet light at room temperature.

[0026] Fig.15 The figure shows the repeatability test result of the gas sensor prepared by the gas-sensitive material of Example 2 of the present invention under the recovery of ultraviolet light at room temperature.

[0027] Fig.16 The figure shows a curve of the resistance value of the detection resistor of the gas-sensitive element prepared by the gas-sensitive material of Example 2 of the present invention changing with humidity when the gas-sensitive element is restored by ultraviolet light at room temperature.

[0028] Fig.17 The figure shows a line graph showing the change in sensitivity of the gas-sensitive element prepared from the gas-sensitive material of Example 2 of the present invention at room temperature after recovery by ultraviolet light irradiation as a function of humidity. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further explained below in conjunction with specific implementation cases and drawings.

[0030] The present invention provides a UV-assisted MOF-derived AuRu-In 2 O 3 A method for preparing a gas-sensitive material, the method comprising the following steps: Step 1: Dissolve 0.8-1.5 mmol indium nitrate in 20-40 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 0.5-1.5 mmol of terephthalic acid and 0.5-1.5 mmol of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 20-40 minutes at a stirring rate of 800-1000 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:0.5~1.5:0.5~1.5; Step 3: placing the mixed solution in an oven and reacting it at 100-140°C for 0.5-1.5 h. After the reaction, cooling the mixed solution for 10-15 h, centrifuging it, taking the precipitate and washing it alternately with deionized water and anhydrous ethanol for 5-7 times, and then placing the washed precipitate in an oven at 60-80°C and drying it for 5-10 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 400-600° C. for 2-3 hours at a heating rate of 1-3° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10-30 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, perform ultrasonication for 5-10 min, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: Prepare RuCl at a concentration of 0.5 mg / mL at room temperature. 3 Solution, HAuCl at a concentration of 20 mg / mL 4 ·4H 2 O solution, NaBH at a concentration of 0.05 mmol / mL 4 Solution; Step 7: Take 3-10 μL of the above HAuCl 4 ·4H 2 HO solution and 5-15 μL of RuCl 3 The solution was slowly added to the indium oxide suspension in step 5, and magnetic stirring was performed for 10-20 min; then 40-60 μL of the above NaBH was slowly added. 4 The solution is stirred magnetically for 10-30 min at a stirring rate of 800-1000 rpm; then it is allowed to stand for 3-5 h, after which it is centrifuged, the precipitate is taken and washed alternately with ethanol and deionized water for 5-7 times, and then the precipitate is placed in an oven and dried for 5-10 h to obtain the metal organic framework-derived AuRu-In 2 O 3 Gas sensitive materials.

[0031] The AuRu-In 2 O 3 In the gas-sensitive material, the molar ratio of its components is In 2 O 3 : Au: Ru=100: 0.5~1.5: 0.5~1.5.

[0032] The dripping rate of the above slow dripping is 0.5-1 μL / s.

[0033] Furthermore, the present invention provides a UV-assisted MOF-derived AuRu-In 2 O 3 Method for using the gas sensing material, the AuRu-In 2 O 3 The gas-sensitive material is obtained by the above-mentioned preparation method, and its use method comprises the following steps: Step 1) Place the AuRu-In 2 O 3 The gas-sensitive material is used as the gas-sensitive material of the gas-sensitive element to make the indirectly heated gas-sensitive element. The specific steps include: Step 1.1: Take the AuRu-In as described above 2 O3 1-3 mg of the gas-sensitive material is mixed with 1-3 mL of deionized water to form a paste, and then the paste is evenly coated on the surface of the ceramic tube between the two annular and parallel metal electrodes of the indirectly heated gas-sensitive element with a brush. The thickness of the paste is 5-15 μm. Step 1.2: Place the ceramic tube coated with the paste under a fast drying lamp for 5-10 minutes to form a coating; then weld the ceramic tube to the hexagonal base, set the resistance wire inside the ceramic tube to heat the ceramic tube, and connect the two ends of the resistance wire to the No. 1 and No. 6 connection pins through platinum wires. Two annular metal electrodes are provided with a connection point at each end of the outer diameter passing through the center of the circle, and the four connection points are connected to the No. 2, No. 3, No. 4, and No. 5 connection pins through platinum wires to obtain AuRu-In 2 O 3 Gas sensing elements of gas sensitive materials.

[0034] The gas sensor is connected to the circuit through its No. 1-No. 6 connection pins, wherein the No. 1 and No. 6 connection pins connect the resistance wire in parallel to the circuit so that the resistance wire obtains the working voltage and generates heat; the two connection pins on each annular metal electrode are connected in parallel to form a terminal, the coating between the two annular metal electrodes is the detection resistor, and the two terminals connect the detection resistor to the circuit.

[0035] The working principle of the gas sensor is: the resistance value of the detection resistor changes due to the oxidation and reduction reaction of the gas on the surface of the semiconductor coating. When the semiconductor coating is heated to a stable state, the gas contacts the surface of the semiconductor coating, and the adsorbed molecules react with the semiconductor coating, resulting in a change in the charge layer on the surface of the semiconductor coating, thereby changing the carrier concentration of the semiconductor coating, which ultimately manifests as a change in the resistance value of the detection resistor, that is, a change in the resistance value of the gas sensor.

[0036] The gas sensing characteristics of a gas sensor are usually characterized by sensitivity. In the technical solution of the present invention, when the gas sensor does not use an ultraviolet device to assist in sensitization, the definition of sensitivity is the stable resistance value R of the gas sensor in the atmosphere. a The stable resistance value R of the gas sensor in the measured gas atmosphere g Ratio: S=R a / R g When the gas sensor is irradiated with ultraviolet light to promote the desorption of gas molecules and the recovery of the resistance of the gas-sensitive material, the sensitivity is defined as the stable resistance value R of the gas sensor in the atmosphere after irradiation with ultraviolet light. UV The stable resistance value R of the gas sensor in the measured gas atmosphere g Ratio: S=R UV / Rg The response time is the time required for the device resistance value to change by 90% of the total change when the sensor device is transferred from air atmosphere to the target gas.

[0037] Step 2) Connect the above-mentioned gas sensor to the circuit, load the working voltage at both ends of the resistance wire, so that the resistance wire heats up and generates heat, so that the gas sensor obtains different working temperatures; two annular metal electrodes connect the detection resistor of the gas sensor with a load resistor in series through their connection terminals to form a series resistance circuit, and the test voltage V is supplied to both ends of the series resistance circuit. c , the voltage across the load resistor is the output voltage V out , the resistance value of the detection resistor R 1 =V c / V out (1-R 0 ), R 0 is the resistance value of the load resistor; at the test voltage V c When the resistance of the detection resistor remains unchanged, the resistance value of the detection resistor changes with the temperature in the environment and the type and concentration of the target gas.

[0038] Step 3) Place the gas sensor in a 1L air bottle and wait for the resistance value of the gas sensor's detection resistor to stabilize at the operating temperature (room temperature: 25℃ or low temperature: 175℃-225℃); then place the gas sensor in a 1L glass container filled with the target gas and wait for the resistance value of its detection resistor to stabilize. Record the resistance value as R g .

[0039] Step 4) Transfer the gas sensor to a 1L quartz glass bottle that is transparent to ultraviolet light, turn on the ultraviolet lamp with a wavelength of 300-400 nm, and place the quartz glass bottle directly opposite the ultraviolet lamp with a horizontal distance of 5-10 cm to promote the desorption of gas molecules on the surface of the gas-sensitive material until the resistance value of the detection resistor of the gas-sensitive material is stable. Record the resistance value of the detection resistor of the gas sensor after desorption as R UV , turn off the UV lamp.

[0040] Step 5) Use the obtained R UV , R g , calculate the sensitivity S=R UV / R g ; According to the sensitivity of target gas with different concentrations, draw the correlation curve between the concentration and sensitivity of the target gas.

[0041] Step 6) Place the gas sensor in a 1L glass container filled with a target gas of unknown concentration, wait for the resistance value of its detection resistor to stabilize, and record the resistance value at this time. Then repeat the operation of step 4) to record the resistance value of the detection resistor of the gas sensor after desorption; based on the above two resistance values, obtain the sensitivity value of the target gas of unknown concentration; substitute the sensitivity value into the correlation curve in step 5) to obtain the concentration value of the target gas of unknown concentration.

[0042] Example 1 This embodiment provides a UV-assisted sensitization MOF-derived AuRu-In 2 O 3 A method for preparing a gas-sensitive material, the method comprising the following steps: Step 1: Dissolve 1 mmoL of indium nitrate in 30 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 1 mmoL of terephthalic acid and 1 mmoL of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 30 minutes at a stirring rate of 900 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:1:1; Step 3: Place the mixed solution in an oven and react at 120°C for 1 h. After the reaction, cool the mixed solution for 12 h, centrifuge it, take the precipitate and wash it alternately with deionized water and anhydrous ethanol for 6 times, then place the washed precipitate in an oven at 60°C and dry it for 8 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 500° C. for 2 hours at a heating rate of 2° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, ultrasonicate for 5 minutes, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: Prepare RuCl at a concentration of 0.5 mg / mL at room temperature. 3 Solution, HAuCl at a concentration of 20 mg / mL 4 ·4H 2 O solution, NaBH at a concentration of 0.05 mmol / mL 4 Solution; Step 7: Take 4 μL of the above HAuCl 4 ·4H 2 HO solution and 15 μL of RuCl 3The solution was slowly added to the indium oxide suspension in step 5, and magnetic stirring was performed for 10 min; then 40 μL of the above-mentioned NaBH was slowly added. 4 The solution was stirred magnetically for 10 min at a stirring rate of 900 rpm; then it was allowed to stand for 4 h, after which it was centrifuged, the precipitate was taken and washed alternately with ethanol and deionized water for 6 times, and then the precipitate was placed in an oven and dried for 8 h to obtain the metal organic framework-derived AuRu-In 2 O 3 Gas sensitive materials.

[0043] The AuRu-In 2 O 3 In the gas-sensitive material, the molar ratio of its components is In 2 O 3 : Au:Ru=100: 0.5: 1.

[0044] Example 2 This embodiment provides a UV-assisted sensitization MOF-derived AuRu-In 2 O 3 A method for preparing a gas-sensitive material, the method comprising the following steps: Step 1: Dissolve 1 mmoL of indium nitrate in 30 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 1 mmoL of terephthalic acid and 1 mmoL of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 30 minutes at a stirring rate of 900 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:1:1; Step 3: Place the mixed solution in an oven and react at 120°C for 1 h. After the reaction, cool the mixed solution for 12 h, centrifuge it, take the precipitate and wash it alternately with deionized water and anhydrous ethanol for 6 times, then place the washed precipitate in an oven at 60°C and dry it for 8 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 500° C. for 2 hours at a heating rate of 2° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, ultrasonicate for 5 minutes, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: Prepare RuCl at a concentration of 0.5 mg / mL at room temperature. 3 Solution, HAuCl at a concentration of 20 mg / mL4 ·4H 2 O solution, NaBH at a concentration of 0.05 mmol / mL 4 Solution; Step 7: Take 5.5 μL of the above HAuCl 4 ·4H 2 HO solution and 11.5 μL of RuCl 3 The solution was slowly added to the indium oxide suspension in step 5, and magnetic stirring was performed for 10 min; then 40 μL of the above-mentioned NaBH was slowly added. 4 The solution was stirred magnetically for 10 min at a stirring rate of 900 rpm; then it was allowed to stand for 4 h, after which it was centrifuged, the precipitate was taken and washed alternately with ethanol and deionized water for 6 times, and then the precipitate was placed in an oven and dried for 8 h to obtain the metal organic framework-derived AuRu-In 2 O 3 Gas sensitive materials.

[0045] The AuRu-In 2 O 3 In the gas-sensitive material, the molar ratio of its components is In 2 O 3 : Au:Ru=100: 0.75:0.75.

[0046] The Au prepared in this example 0.75 Ru 0.75 -In 2 O 3 SEM images of the materials are shown in Figure 4 As shown, it can be observed that its morphology is porous nanocluster-like and the particle size is 100-200nm.

[0047] Example 3 This embodiment provides a UV-assisted sensitization MOF-derived AuRu-In 2 O 3 A method for preparing a gas-sensitive material, the method comprising the following steps: Step 1: Dissolve 1 mmoL of indium nitrate in 30 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 1 mmoL of terephthalic acid and 1 mmoL of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 30 minutes at a stirring rate of 900 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:1:1; Step 3: Place the mixed solution in an oven and react at 120°C for 1 h. After the reaction, cool the mixed solution for 12 h, centrifuge it, take the precipitate and wash it alternately with deionized water and anhydrous ethanol for 6 times, then place the washed precipitate in an oven at 60°C and dry it for 8 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 500° C. for 2 hours at a heating rate of 2° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, ultrasonicate for 5 minutes, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: Prepare RuCl at a concentration of 0.5 mg / mL at room temperature. 3 Solution, HAuCl at a concentration of 20 mg / mL 4 ·4H 2 O solution, NaBH at a concentration of 0.05 mmol / mL 4 Solution; Step 7: Take 7.5 μL of the above HAuCl 4 ·4H 2 HO solution and 7.5 μL of RuCl 3 The solution was slowly added to the indium oxide suspension in step 5, and magnetic stirring was performed for 10 min; then 40 μL of the above-mentioned NaBH was slowly added. 4 The solution was stirred magnetically for 10 min at a stirring rate of 900 rpm; then it was allowed to stand for 4 h, after which it was centrifuged, the precipitate was taken and washed alternately with ethanol and deionized water for 6 times, and then the precipitate was placed in an oven and dried for 8 h to obtain the metal organic framework-derived AuRu-In 2 O 3 Gas sensitive materials.

[0048] The AuRu-In 2 O 3 In the gas-sensitive material, the molar ratio of its components is In 2 O 3 : Au:Ru=100: 1: 0.5.

[0049] Comparative Example 1 This comparative example provides a gas-sensitive material, which is prepared by the following steps: Step 1: Dissolve 1 mmoL of indium nitrate in 30 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 1 mmoL of terephthalic acid and 1 mmoL of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 30 minutes at a stirring rate of 900 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:1:1; Step 3: Place the mixed solution in an oven and react at 120°C for 1 h. After the reaction, cool the mixed solution for 12 h, centrifuge it, take the precipitate and wash it alternately with deionized water and anhydrous ethanol for 6 times, then place the washed precipitate in an oven at 60°C and dry it for 8 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing it at 500°C for 2 hours at a heating rate of 2°C / min, then naturally cooling it to room temperature, and collecting the yellow powdery indium oxide gas-sensitive material; The In prepared in this comparative example 2 O 3 SEM images of the materials are shown in Figure 3 As shown, it can be observed that its morphology is porous nanocluster-like.

[0050] Comparative Example 2 This comparative example provides a gas-sensitive material, which is prepared by the following steps: Step 1: Dissolve 1 mmoL of indium nitrate in 30 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 1 mmoL of terephthalic acid and 1 mmoL of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 30 minutes at a stirring rate of 900 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:1:1; Step 3: Place the mixed solution in an oven and react at 120°C for 1 h. After the reaction, cool the mixed solution for 12 h, centrifuge it, take the precipitate and wash it alternately with deionized water and anhydrous ethanol for 6 times, then place the washed precipitate in an oven at 60°C and dry it for 8 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 500° C. for 2 hours at a heating rate of 2° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, ultrasonicate for 5 minutes, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: Prepare HAuCl at a concentration of 20 mg / mL at room temperature. 4 ·4H 2 O solution, NaBH at a concentration of 0.05 mmol / mL 4 Solution; Step 7: Take 5.5 μL of the above HAuCl 4 ·4H 2 O solution was slowly added dropwise to the indium oxide suspension in step 5 and magnetically stirred for 10 min; then 40 μL of the above-mentioned NaBH 4 The solution was stirred magnetically for 10 min at a stirring rate of 900 rpm; then it was allowed to stand for 4 h, after which it was centrifuged, the precipitate was taken and washed alternately with ethanol and deionized water for 6 times, and then the precipitate was placed in an oven and dried for 8 h to obtain Au-In 2 O 3 Gas sensitive materials.

[0051] The Au-In 2 O 3 In the gas-sensitive material, the molar ratio of its components is In 2 O 3 : Au =100:0.75.

[0052] Comparative Example 3 This comparative example provides a gas-sensitive material, which is prepared by the following steps: Step 1: Dissolve 1 mmoL of indium nitrate in 30 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, add 1 mmoL of terephthalic acid and 1 mmoL of trimesic acid to the above indium nitrate solution, and stir magnetically at room temperature for 30 minutes at a stirring rate of 900 rpm to obtain a mixed solution. In the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:1:1; Step 3: Place the mixed solution in an oven and react at 120°C for 1 h. After the reaction, cool the mixed solution for 12 h, centrifuge it, take the precipitate and wash it alternately with deionized water and anhydrous ethanol for 6 times, then place the washed precipitate in an oven at 60°C and dry it for 8 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 500° C. for 2 hours at a heating rate of 2° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, ultrasonicate for 5 minutes, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: Prepare RuCl at a concentration of 0.5 mg / mL at room temperature. 3 Solution, concentration 0.05 mmol / mL NaBH 4 Solution; Step 7: Take 11.5 μL of RuCl 3 The solution was slowly added to the indium oxide suspension in step 5, and magnetic stirring was performed for 10 min; then 40 μL of the above-mentioned NaBH was slowly added. 4 The solution was stirred magnetically for 10 min at a stirring rate of 900 rpm; then it was allowed to stand for 4 h, after which it was centrifuged, the precipitate was taken and washed alternately with ethanol and deionized water for 6 times, and then the precipitate was placed in an oven and dried for 8 h to obtain Ru-In 2 O 3 Gas sensitive materials.

[0053] Ru-In 2 O 3 In the gas-sensitive material, the molar ratio of its components is In 2 O 3 : Ru=100: 0.75.

[0054] The three AuRu-In obtained in Example 1, Example 2 and Example 3 2 O 3 Gas-sensitive material and the indium oxide gas-sensitive material obtained in Comparative Example 1, and the AuRu-In obtained in Comparative Example 2 2 O 3 Gas-sensitive material and Ru-In obtained in Comparative Example 3 2 O 3 The gas-sensitive materials are prepared into indirectly heated gas-sensitive elements according to the following methods: Step 1: Take 2 mg of a gas-sensitive material as described above, mix it with 2 mL of deionized water to make a paste, and then use a brush to evenly apply the paste on the surface of the ceramic tube between two annular and parallel metal electrodes of the indirectly heated gas sensor. The thickness of the paste is 10 μm. Step 2: Place the ceramic tube coated with the paste under a quick drying lamp and bake for 10 minutes to form a coating; then weld the ceramic tube to the hexagonal base, and set the resistance wire inside the ceramic tube to heat the ceramic tube. The two ends of the resistance wire are connected to the No. 1 and No. 6 connecting pins respectively through platinum wires. Two annular metal electrodes are respectively provided with a connection point at both ends of the outer diameter passing through the center of the circle. The four connection points are respectively connected to the No. 2, No. 3, No. 4, and No. 5 connecting pins through platinum wires to obtain a gas-sensitive element containing corresponding gas-sensitive materials.

[0055] The preparation method of the above-mentioned gas sensor is a prior art; The gas sensor is tested for its gas-sensitive properties using a gas-sensitive test system (FLUKE). The gas-sensitive test system (FLUKE) is a prior art. When testing a gas sensor, under normal test conditions (without UV light), the sensitivity is defined as the stable resistance value R of the gas sensor in the atmosphere. a The stable resistance value R of the gas sensor in the measured gas atmosphere g Ratio: S=R a / R g Under ultraviolet irradiation conditions, the gas sensor uses ultraviolet light to promote the desorption of gas molecules. The sensitivity is defined as the stable resistance value R of the gas sensor in the atmosphere after being irradiated by ultraviolet light. UV The stable resistance value R of the gas sensor in the measured gas atmosphere g Ratio: S=R UV / R g .

[0056] Figure 5 The response curves of the gas sensors prepared by the gas-sensitive materials in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3 respectively with the change of working temperature (conventional test conditions). Among them, the best working temperature of the gas sensor in Example 1 is 175°C, and the response to 50 ppm triethylamine is 371, the best working temperature of the gas sensor in Example 2 is 175°C, and the response to 50 ppm triethylamine is 756, and the best working temperature of the gas sensor in Example 3 is 175°C, and the response to 50 ppm triethylamine is 620; the best working temperature of the gas sensor in Comparative Example 1 is 200°C, and the response to 50 ppm triethylamine is 27, the best working temperature of the gas sensor in Comparative Example 2 is 175°C, and the response to 50 ppm triethylamine is 106, and the best working temperature of the gas sensor in Comparative Example 2 is 175°C, and the response to 50 ppm triethylamine is 206.

[0057] Figure 8 and Fig. 9The gas sensors prepared from the gas-sensitive materials in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3 are respectively shown as line graphs of sensitivity changes with concentration in the high concentration (10 ppb-50 ppm) range and the low concentration (10 ppb-1 ppm) range (conventional test conditions); the results show that, except for the gas-sensitive element prepared from the gas-sensitive material in Comparative Example 1, the detection limit of the other five gas-sensitive elements is 10 ppb, and the linear relationship between concentration and response is good. In addition, the gas-sensitive elements corresponding to the gas-sensitive materials in Example 1, Example 2, and Example 3 respond faster, while the gas-sensitive element corresponding to the gas-sensitive material in Example 2 responds the fastest.

[0058] Figure 7 The response diagram of the gas-sensitive element prepared by the gas-sensitive material of Example 2 to 50 ppm triethylamine and 100 ppm other different gases at the optimal working temperature of 175°C (conventional test conditions) shows that the gas-sensitive element prepared by the gas-sensitive material of Example 2 has very good selectivity for triethylamine.

[0059] Fig.10 This is a curve showing the sensitivity of the gas-sensitive element prepared from the gas-sensitive material of Example 2 at an optimal working temperature of 175°C versus concentration (conventional test conditions).

[0060] Fig.11 This is a comparison chart of the recovery time of the gas sensor prepared by the gas-sensitive material of Example 2 in air (conventional test conditions) and under ultraviolet light irradiation (ultraviolet irradiation conditions), wherein the gray shadow part is the data under ultraviolet light irradiation; the results show that in the recovery process of the gas sensor, Au 0.75 Ru 0.75 -In 2 O 3 The response to triethylamine increased to 835, and the recovery time was significantly shortened.

[0061] Fig.12 The gas-sensitive element prepared with the gas-sensitive material of Example 2 shows a response test chart of 50 ppm triethylamine and 100 ppm other gases under the irradiation of ultraviolet lamp at room temperature. Similarly, ultraviolet lamp irradiation is only used during the recovery process of the gas-sensitive element. The results show that the gas-sensitive element has good selectivity for triethylamine under this environment.

[0062] Fig.13 The sensitivity curve of the gas sensor prepared by the gas-sensitive material of Example 2 with different concentrations of triethylamine under the recovery of ultraviolet light at room temperature shows that the lowest concentration of triethylamine that can be detected is 50 ppb.

[0063] Fig.14The sensitivity of the gas-sensitive element prepared by the gas-sensitive material of Example 2 varies with the concentration of triethylamine (i.e., select Fig.13 The concentration values ​​in the graph are plotted against the corresponding sensitivities), and the results show that the two have a good linear relationship.

[0064] Fig.15 The gas-sensitive element prepared with the gas-sensitive material of Example 2 was tested for repeatability at room temperature under recovery with the aid of ultraviolet light. The results showed that, compared with the case without ultraviolet light, its baseline resistance was greatly improved, the response was greatly improved, and it could recover quickly.

[0065] Fig.17 The sensitivity of the gas sensor prepared by the gas-sensitive material of Example 2 changes with humidity under the recovery of ultraviolet light at room temperature. The results show that with the increase of humidity, the sensitivity first increases significantly, reaches a peak value (2332) at 80% humidity, and then decreases, indicating that the gas sensor in Example 2 has high moisture resistance with the assistance of ultraviolet light, and is even more suitable for detecting triethylamine in a relatively humid environment.

[0066] The present invention prepares an oxide semiconductor gas-sensitive material that is sensitive to triethylamine, which can achieve high-performance identification of triethylamine at room temperature and low temperature with the assistance of an ultraviolet lamp, and can detect the presence of trace amounts of triethylamine. The material preparation process is simple, and has excellent properties such as low operating temperature, high sensitivity, high selectivity, and high moisture resistance.

[0067] The above embodiments are for illustration only and are not intended to be limiting. Any equivalent modifications or changes made thereto without departing from the spirit and scope of the present invention shall be included in the scope of the claims of this application.

[0068] Any matters not described in the present invention are applicable to the prior art.

Claims

1. A method for preparing a UV-assisted MOF-derived AuRu-In2O3 gas-sensitive material, characterized in that: The method comprises the following steps: Step 1: Dissolve 0.8-1.5 mmol indium nitrate in 20-40 mL of N-N-dimethylformamide at room temperature and stir magnetically until completely dissolved to obtain an indium nitrate solution; Step 2: Under magnetic stirring, 0.5-1.5 mmol of terephthalic acid and 0.5-1.5 mmol of trimesic acid are added to the above indium nitrate solution, and magnetic stirring is performed at room temperature for 20-40 minutes at a stirring rate of 800-1000 rpm to obtain a mixed solution; in the mixed solution, the molar ratio of indium nitrate, terephthalic acid, and trimesic acid is 1:0.5~1.5:0.5~1.5; Step 3: placing the mixed solution in an oven and reacting it at 100-140°C for 0.5-1.5 h. After the reaction, cooling the mixed solution for 10-15 h, centrifuging it, taking the precipitate and washing it alternately with deionized water and anhydrous ethanol for 5-7 times, and then placing the washed precipitate in an oven at 60-80°C and drying it for 5-10 hours; Step 4: placing the dried precipitate in step 3 in a muffle furnace, annealing at 400-600° C. for 2-3 hours at a heating rate of 1-3° C. / min, then naturally cooling to room temperature, and collecting yellow indium oxide powder material; Step 5: Take 10-30 mg of the yellow indium oxide powder material in step 4 and place it in 20 mL of deionized water, perform ultrasonication for 5-10 minutes, and stir magnetically until the mixture is uniform to obtain an indium oxide suspension; Step 6: At room temperature, prepare a 0.5 mg / mL RuCl3 solution, a 20 mg / mL HAuCl4·4H2O solution, and a 0.05 mmol / mL NaBH4 solution; Step 7: Take 3-10 μL of the above-mentioned HAuCl4·4H2O solution and 5-15 μL of RuCl3 solution and slowly add them to the indium oxide suspension in step 5 in sequence, and stir them magnetically for 10-20 min; then slowly add 40-60 μL of the above-mentioned NaBH4 solution, stir them magnetically for 10-30 min, and the stirring rate is 800-1000 rpm; then let it stand for 3-5 h, then centrifuge it, take the precipitate and wash it alternately with ethanol and deionized water for 5-7 times, then place the precipitate in an oven and dry it for 5-10 h to obtain the metal organic framework-derived AuRu-In2O3 gas-sensitive material.

2. The method for preparing a UV-assisted sensitized MOF-derived AuRu-In2O3 gas-sensitive material according to claim 1, characterized in that: The AuRu-In2O3 gas-sensitive material obtained by this method has a molar ratio of In2O3: Au: Ru=100: 0.5~1.5: 0.5~1.

5.

3. The method for preparing a UV-assisted sensitized MOF-derived AuRu-In2O3 gas-sensitive material according to claim 1, characterized in that: The dripping rate of the slow dripping is 0.5-1 μL / s.

4. A method for using a UV-assisted MOF-derived AuRu-In2O3 gas-sensitive material, characterized in that: The AuRu-In2O3 gas-sensitive material is obtained by the preparation method according to any one of claims 1 to 3, and the use method thereof comprises the following steps: Step 1) using the AuRu-In2O3 gas-sensitive material as the gas-sensitive material of the gas-sensitive element to prepare a indirectly heated gas-sensitive element; Step 2) Connect the above-mentioned gas sensor to the circuit, load the working voltage at both ends of the resistance wire, so that the resistance wire heats up and generates heat, so that the gas sensor obtains different working temperatures; two annular metal electrodes connect the detection resistor of the gas sensor with a load resistor in series through their connection terminals to form a series resistance circuit, and the test voltage V is supplied to both ends of the series resistance circuit. c , the voltage across the load resistor is the output voltage V out , the resistance value of the detection resistor R1=V c / V out (1-R0), R0 is the resistance value of the load resistor; at the test voltage V c Under the condition of no change, the resistance value of the detection resistor changes with the temperature in the environment and the type and concentration of the target gas; Step 3) Place the gas sensor in a 1L air bottle and wait for the resistance value of the gas sensor's detection resistor to stabilize at the operating temperature; then place the gas sensor in a 1L glass container filled with the target gas and wait for the resistance value of its detection resistor to stabilize. Record the resistance value at this time as R g ; Step 4) Transfer the gas sensor to a 1L quartz glass bottle that is transparent to ultraviolet light, turn on the ultraviolet lamp with a wavelength of 300-400 nm, and place the quartz glass bottle directly opposite the ultraviolet lamp with a horizontal distance of 5-10 cm to promote the desorption of gas molecules on the surface of the gas-sensitive material until the resistance value of the detection resistor of the gas-sensitive material is stable. Record the resistance value of the detection resistor of the gas sensor after desorption as R UV , turn off the UV lamp; Step 5) Use the obtained R UV , R g , calculate the sensitivity S=R UV / R g ; According to the sensitivity of target gas with different concentrations, draw the correlation curve between the concentration and sensitivity of target gas; Step 6) Place the gas sensor in a 1L glass container filled with a target gas of unknown concentration, wait for the resistance value of its detection resistor to stabilize, and record the resistance value at this time; then repeat the operation of step 4) to record the resistance value of the detection resistor of the gas sensor after desorption; based on the above two resistance values, obtain the sensitivity value of the target gas of unknown concentration; substitute the sensitivity value into the correlation curve in step 5) to obtain the concentration value of the target gas of unknown concentration.

5. The method for using a UV-assisted sensitized MOF-derived AuRu-In2O3 gas-sensitive material according to claim 4, characterized in that: In step 1), the process of making the indirectly heated gas sensor specifically includes the following steps: Step 1.1: Take 1-3 mg of AuRu-In2O3 gas-sensitive material, mix it with 1-3 mL of deionized water to make a paste, and then use a brush to evenly apply the paste on the surface of the ceramic tube between the two annular and parallel metal electrodes of the indirectly heated gas sensor. The thickness of the paste is 5-15 μm. Step 1.2: Place the ceramic tube coated with the paste under a fast drying lamp and bake for 5-10 minutes to form a coating; then weld the ceramic tube to the hexagonal base, and set the resistance wire inside the ceramic tube to heat the ceramic tube. The two ends of the resistance wire are connected to the No. 1 and No. 6 connecting pins respectively through platinum wires. Two annular metal electrodes are respectively provided with a connection point at both ends of the outer diameter passing through the center of the circle. The four connection points are respectively connected to the No. 2, No. 3, No. 4, and No. 5 connecting pins through platinum wires to obtain a gas sensitive element containing AuRu-In2O3 gas sensitive material.

6. The method for using the UV-assisted sensitized MOF-derived AuRu-In2O3 gas-sensitive material according to claim 4, characterized in that: In step 3), the working temperature is 25°C or 175°C-225°C.

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