GaN@Sn-based composite gas-sensitive material, preparation method and application thereof

Abstract

The application discloses a kind of GaN@Sn-based composite gas-sensitive materials and its preparation method and application, specifically related to hydrogen sulfide gas detection technical field, comprising: (1) tin tetrachloride is mixed with anhydrous ethanol, water stirring;Hydrochloric acid is added to obtain mixed solution;Centrifugal, washing, drying obtain SnO2 nanosphere;(2) the SnO2 nanosphere obtained in step (1) is mixed with hydrated gallium nitrate, urea, grinds;Calcination is obtained.The GaN@Sn-based composite gas-sensitive material prepared is dispersed in anhydrous ethanol, is dropped on the surface of plane electrode by pipette gun and dried, finally welded on sensing base by precision spot welding machine, and is constructed into semiconductor sensor for detecting hydrogen sulfide gas.This preparation procedure is simple and easy to operate, and the sensor constructed is used for environmental monitoring and human health protection, and has rapid response and high sensitivity.

Description

Technical Field

[0001] This invention relates to the field of hydrogen sulfide gas detection technology, specifically to a GaN@Sn-based composite gas-sensitive material, its preparation method, and its application. Background Technology

[0002] Hydrogen sulfide is widely found in nature. It is a colorless, rotten egg-smelling, highly irritating neurotoxic gas, with a toxicity approximately equivalent to cyanide. As a toxic substance, it poses a significant threat to human health and the atmospheric environment. Even low concentrations can damage the nervous system, causing serious harm to the eyes and central nervous system. High concentrations of hydrogen sulfide can cause paralysis and even death. Accurate detection of hydrogen sulfide is crucial for both environmental monitoring and human health protection; therefore, utilizing readily fabricated, high-performance hydrogen sulfide gas sensors for real-time monitoring and early warning is of paramount importance.

[0003] In recent years, wide-bandgap semiconductor materials, represented by GaN, have been termed third-generation semiconductor materials. They possess not only high electron mobility, high critical breakdown field strength, and high thermal conductivity, but also excellent chemical stability and radiation resistance. GaN gas sensors offer numerous advantages, including fast response, low power consumption, and small size. The mechanism of GaN gas sensors is similar to that of semiconductor metal oxide sensors; the adsorption and desorption of oxygen in the air and its reaction with target gas molecules on the surface cause changes in conductivity, and GaN maintains excellent gas detection performance even in harsh environments. The market for GaN gas sensors is continuously expanding. Currently, GaN gas sensors primarily detect gases such as nitric oxide and nitrogen dioxide, but cases of detecting hydrogen sulfide are rare.

[0004] Chinese patent application CN115057437A discloses a SnO2 / NiO / graphene ternary composite material, its preparation method, and its applications. Based on the Hummers method for preparing graphene oxide (GO) and surface-controlled semiconductor sensitive materials, a ternary composite material of tin oxide / nickel oxide / reduced graphene oxide nanosieves (SnO2 / NiO / HrGO) is obtained using solvothermal processes, oxidative etching, and high-temperature annealing, achieving high-response room-temperature detection of NO2. However, the patent does not mention the detection of hydrogen sulfide gas, and the preparation method is complex, thus requiring further improvement.

[0005] Based on this, the present invention is proposed. Summary of the Invention

[0006] The technical problem to be solved by this invention is how to provide a method for constructing GaN@Sn-based composite gas-sensitive materials for hydrogen sulfide gas detection and its application.

[0007] The present invention solves the above-mentioned technical problems through the following technical means:

[0008] This invention proposes a method for preparing GaN@Sn-based composite gas-sensitive materials, comprising the following steps: (1) Mix tin tetrachloride with anhydrous ethanol and water; add hydrochloric acid to react and obtain a mixture; centrifuge, wash and dry to obtain SnO2 nanospheres; (2) Mix the SnO2 nanospheres obtained in step (1) with gallium nitrate and urea, grind them, and calcine them to obtain the final product.

[0009] Preferably, in step (1), the ratio of tin tetrachloride, anhydrous ethanol, water and hydrochloric acid is (0.5-1)g:(30-50)mL:(3-5)mL:(0.5-1)mL; more preferably, it is 0.8g:50mL:5mL:0.8mL.

[0010] Preferably, in step (1), the mixing method is to stir at a speed of (600-800) rpm for (30-60) min; more preferably, it is 800 rpm for 30 min.

[0011] Preferably, in step (1), the reaction conditions are 150-200℃ for 11-13h, and more preferably 175℃ for 12.5h.

[0012] Preferably, in step (1), the centrifugation conditions are centrifugation at a speed of (6000-8000) r / min for (5-10) min, and more preferably 8000 r / min for 5 min.

[0013] Preferably, in step (1), the drying conditions are drying at (60-80)℃ for (10-12)h, and more preferably at 60℃ for 12h.

[0014] Preferably, in step (2), the ratio of SnO2 nanospheres, gallium nitrate, and urea is (5-10) mg: (200-250) mg: (1-2) g, and more preferably 10 mg: 250 mg: 2 g.

[0015] Preferably, in step (2), the calcination conditions are to raise the temperature to (800-850)℃ at a heating rate of 2℃ / min under a nitrogen atmosphere and hold for 1-2 hours, and more preferably to raise the temperature to 850℃ and hold for 1 hour.

[0016] This invention also proposes a GaN@Sn-based composite gas-sensitive material prepared by the above preparation method.

[0017] This invention also proposes the application of the GaN@Sn-based composite gas-sensitive material prepared by the above method in the construction of a hydrogen sulfide gas sensor.

[0018] The application involves dispersing the aforementioned GaN@Sn-based composite gas-sensitive material in anhydrous ethanol, then drop-coating it onto the surface of a planar electrode using a pipette, and allowing it to dry completely to construct a semiconductor sensor that can be used to detect hydrogen sulfide gas.

[0019] Preferably, the ratio of GaN@Sn-based composite gas-sensitive material to anhydrous ethanol is 1-2 mg: 15-30 μL; more preferably, it is 2 mg: 30 μL.

[0020] The beneficial effects of this invention are as follows: 1. The preparation method of the GaN@Sn-based composite gas-sensitive material provided by the present invention is simple and easy to operate, and the sensor constructed based on the obtained GaN@Sn-based composite gas-sensitive material exhibits excellent sensing characteristics with high sensitivity to hydrogen sulfide gas.

[0021] 2. When the GaN@Sn-based composite gas-sensitive material provided by this invention is used in the construction process of a hydrogen sulfide gas sensor, the prepared GaN@Sn-based composite gas-sensitive material is processed through a sensor sensitive thin film process to construct a hydrogen sulfide gas sensor, which can achieve a rapid response to hydrogen sulfide gas and exhibit excellent gas-sensitive characteristics.

[0022] 3. The hydrogen sulfide gas sensor based on GaN@Sn-based composite gas-sensitive material proposed in this invention has broad application prospects. It can be used for high-sensitivity monitoring of hydrogen sulfide gas and can also monitor the environment in real time, providing strong support for environmental protection.

[0023] Of course, implementing any product or method of the present invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0024] Figure 1 The sensitivity-time curve of the GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material prepared in Example 1 of the present invention for hydrogen sulfide gas at a working temperature of 225°C is shown. Figure 2 This is a scanning electron microscope image of the SnO2 nanosphere material sample prepared in Example 1 of the present invention; Figure 3 Scanning electron microscope (SEM) images of the GaN and GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive materials prepared in Example 1 of this invention.

[0025] Figure 4 The X-ray diffraction pattern of the GaN and GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive materials prepared in Example 1 of this invention; Figure 5This is a comparison chart showing the H2S detection performance of the gas-sensitive materials prepared in Example 1, Comparative Example 1, and Comparative Example 2 of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art.

[0027] Unless otherwise specified, the test materials and reagents used in the following examples are commercially available or prepared by known methods.

[0028] Unless otherwise specified, all techniques or conditions described in the embodiments can be performed in accordance with the techniques or conditions described in the literature in this field or in the product manual. Unless otherwise specified, the quantitative experiments in the following embodiments are all repeated three times or more, and the results are averaged.

[0029] The standard card described in this embodiment of the invention is: PDF#02–1078 (This PDF card is a standard X-ray diffraction phase card for gallium nitride (GaN, hexagonal wurtzite type) in the ICDD standard database), PDF#01-0657 (This PDF card is a standard phase card for tin dioxide (SnO2, rutile type) included in the ICDD Group 1 basic database), PDF#01-0902 (This PDF card is a standard phase card for tin monoxide (SnO, tetragonal system) included in the ICDD Group 1 database), and PDF#01-0926 (This PDF card is a standard diffraction card for metallic tin (Sn, β-Sn white tin, tetragonal system) included in the ICDD Group 1 classification).

[0030] Example 1: This embodiment provides a method for preparing GaN@Sn-based composite gas-sensitive materials, including the following steps: Step A: Mix 0.8 g of tin tetrachloride pentahydrate with 50 mL of anhydrous ethanol and 5 mL of deionized water to obtain a tin tetrachloride mixture. Then, stir the mixture in a stirrer for 10 min until all the solids dissolve. Using a pipette, add 0.8 mL of hydrochloric acid drop by drop along the beaker wall to obtain mixture A. At the same time, stir the mixture magnetically at 800 rpm for 30 min. Then, place the suspension in a stainless steel reactor lined with polytetrafluoroethylene and place the reactor in an oven at 175°C for 12.5 h to obtain mixture B. Step B: Remove the supernatant from mixture B to obtain mixture B. Centrifuge and wash mixture B for 5 min using anhydrous ethanol, a mixture of anhydrous ethanol and deionized water, and deionized water at a speed of 8000 r / min. Place the centrifuged and washed mixture B in an oven at 60 ℃ and dry for 12 h to obtain SnO2 nanospheres. Step C: Take 250 mg of hydrated gallium nitrate (III) (CAS No. 69365-72-6), 2 g of urea, and 10 mg of tin oxide prepared in the previous step. Grind the mixture thoroughly in a mortar, then place it in a tube furnace and raise the temperature inside the tube furnace to 850 °C at a heating rate of 2 °C / min under a nitrogen atmosphere and hold for 1 h to obtain GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material.

[0031] This embodiment also proposes the application of the above-mentioned GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material in the preparation of sensors.

[0032] 2 mg of the GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material prepared above was dispersed in 30 μL of anhydrous ethanol, then dropped onto the surface of the planar electrode with a pipette and dried. Finally, it was welded onto the sensor using a precision spot welding machine.

[0033] In the production process of GaN@Sn-based composite gas-sensitive materials for hydrogen sulfide gas sensors, the prepared composite gas-sensitive materials are processed through sensor sensitive thin film technology to construct hydrogen sulfide gas sensors, which can achieve rapid response to hydrogen sulfide gas and exhibit excellent gas-sensitive characteristics.

[0034] During the morphological observation and performance testing of the GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material samples prepared in the above embodiments, the following results were obtained: like Figure 1The figure shows the dynamic response of a sensor based on GaN@Sn composite gas-sensitive material to seven concentrations of hydrogen sulfide gas (1 ppm, 2.5 ppm, 5 ppm, 7.5 ppm, 10 ppm, 15 ppm, and 20 ppm) at an operating temperature of 42% humidity and 225 °C. The sensitivity of the gas sensor increases with increasing hydrogen sulfide gas concentration, indicating that the fabricated sensor has good reversibility.

[0035] like Figure 2 The image shown is a SEM image of the SnO2 nanospheres prepared in Example 1. It can be seen that the diameter of the prepared SnO2 nanospheres is approximately 4 μm. The SEM characterization results reveal that the SnO2 nanospheres have an uneven surface with a large specific surface area, which promotes absorption and diffusion.

[0036] like Figure 3 The image shows the SEM images of the GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material and GaN prepared in Example 1. It can be seen that GaN exhibits the morphology of nanoparticles with a diameter of 20-30 nm. After modifying pure GaN, the spherical structure of SnO2 material can be clearly seen. With the attachment of Sn-based composite material, GaN and Sn-based composite material are tightly bonded and arranged, which can increase the contact area with gas during the detection process, thereby improving the sensitivity of gas detection.

[0037] like Figure 4 The X-ray diffraction (XRD) patterns of the GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material prepared in Example 1 and GaN are shown. The XRD pattern of the GaN sample clearly shows good agreement with the standard card (PDF#02–1078), confirming the presence of GaN in the composite sample. The XRD patterns of the GaN@Sn-based (SnO2, SnO, Sn) composite gas-sensitive material sample also show good agreement with the standard cards (PDF#02–1078, PDF#01-0657, PDF#01-0902, PDF#01-0926), confirming the presence of GaN, SnO2, SnO, and Sn in the composite sample.

[0038] In summary, the embodiments of the present invention successfully prepared GaN@SnO2 composite gas-sensitive materials, which exhibit excellent gas-sensitive performance at 225°C.

[0039] Example 2: The difference between this embodiment and Embodiment 1 is that: In step A, the ratio of tin tetrachloride, anhydrous ethanol, deionized water, and hydrochloric acid is 0.5g:30mL:3mL:0.5mL; the stirring conditions are 600rpm for 60min and 150℃ for 13h.

[0040] In step B, the centrifugation conditions are 6000 r / min for 10 min and the drying conditions are 80℃ for 10 h.

[0041] In step C, the ratio of SnO2 nanospheres, hydrated gallium nitrate, and urea is 5 mg: 200 mg: 1 g; the calcination conditions are: under a nitrogen atmosphere, the temperature is increased to 800°C at a rate of 2°C / min and held for 2 hours. The rest is the same as in Example 1.

[0042] Example 3: The difference between this embodiment and Embodiment 1 is that: In step A, the ratio of tin tetrachloride, anhydrous ethanol, deionized water, and hydrochloric acid is 1g:50mL:5mL:1mL; the stirring conditions are 800rpm for 30min and 200℃ for 11h.

[0043] In step B, the centrifugation conditions are 8000 r / min for 5 min, and the drying conditions are 60℃ for 12 h.

[0044] In step C, the ratio of SnO2 nanospheres, hydrated gallium nitrate, and urea is 10 mg: 250 mg: 2 g; the calcination conditions are: under a nitrogen atmosphere, the temperature is increased to 850°C at a rate of 2°C / min and held for 1 hour. The rest is the same as in Example 1.

[0045] Comparative Example 1: The difference between this comparative example and Example 1 is that the ratio of SnO2 nanospheres, hydrated gallium nitrate, and urea is 15mg:250mg:2g. Everything else is the same as in Example 1.

[0046] Comparative Example 2: The difference between this comparative example and Example 1 is that the ratio of SnO2 nanospheres, hydrated gallium nitrate, and urea is 20mg:250mg:2g. Everything else is the same as in Example 1.

[0047] like Figure 5 The figure shows a comparison of the H2S detection performance of the gas-sensitive materials prepared in Example 1, Comparative Example 1, and Comparative Example 2. The results show that the gas-sensitive response capability of Comparative Example 1 and Comparative Example 2 to H2S gas is significantly reduced, and the gas response amplitude is greatly reduced, failing to achieve the excellent H2S detection performance of Example 1.

[0048] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a GaN@Sn-based composite gas-sensitive material, characterized in that, Includes the following steps: (1) Mix tin tetrachloride with anhydrous ethanol and water; add hydrochloric acid to react and obtain a mixed solution; SnO2 nanospheres were obtained by centrifugation, washing, and drying. (2) Mix the SnO2 nanospheres obtained in step (1) with gallium nitrate and urea, grind them, and calcine them to obtain the final product.

2. The preparation method according to claim 1, characterized in that, In step (1), the ratio of tin tetrachloride, anhydrous ethanol, water and hydrochloric acid is (0.5-1) g: (30-50) mL: (3-5) mL: (0.5-1) mL.

3. The preparation method according to claim 1, characterized in that, In step (1), the mixing method is to stir at a speed of (600-800) rpm for (30-60) min.

4. The preparation method according to claim 1, characterized in that, In step (1), the reaction conditions are 11-13 h at 150-200 °C.

5. The preparation method according to claim 1, characterized in that, In step (1), the centrifugation conditions are centrifugation at a speed of (6000-8000) r / min for (5-10) min.

6. The preparation method according to claim 1, characterized in that, In step (1), the drying conditions are to dry at (60-80)℃ for (10-12)h.

7. The preparation method according to claim 1, characterized in that, In step (2), the ratio of SnO2 nanospheres, gallium nitrate, and urea is (5-10) mg: (200-250) mg: (1-2) g.

8. The preparation method according to claim 1, characterized in that, In step (2), the calcination conditions are: under a nitrogen atmosphere, the temperature is increased to (800-850)℃ at a heating rate of 2℃ / min.

9. The GaN@Sn-based composite gas-sensitive material prepared by the preparation method according to any one of claims 1-8.

10. The application of the GaN@Sn-based composite gas-sensitive material according to claim 9 in the construction of a hydrogen sulfide gas sensor.

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