Sv-snS2 material based on glucose reduction and preparation method and application thereof

Abstract

The application discloses an Sv-SnS2 material based on glucose reduction and a preparation method and application thereof, a solution containing a tin source and thioacetamide is subjected to a first hydrothermal reaction to obtain SnS2 powder, the SnS2 powder, water, a cationic surfactant and glucose are mixed to obtain a mixed solution, and the mixed solution is subjected to a second hydrothermal reaction to obtain the Sv-SnS2 material. The application improves the concentration of S vacancies in the SnS2 system through the reduction effect of glucose on SnS2, improves the electronic structure, improves the response / recovery performance of a gas sensor, and obtains excellent gas selectivity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of two-dimensional material preparation, and particularly relates to Sv-SnS2 material based on glucose reduction and a preparation method and application thereof. BACKGROUND

[0002] SnS2 is a two-dimensional transition metal sulfide (TMDs), which is a popular two-dimensional material at present. SnS2 is a narrow-band gap interlayer structure TMDs material, has a large specific surface area and high surface activity, and has a wide range of research in photoelectric detectors, catalysis and gas sensitive sensing. However, the gas sensor based on SnS2 still faces challenges in room temperature sensing due to its high baseline resistance and difficulty in recovery at room temperature. In order to adapt to the conditions of low temperature sensing, people have carried out morphology control, heterostructure construction and noble metal modification on it. However, most of these gas sensors based on SnS2 need to work in a high temperature environment. Defect engineering is an effective strategy to improve the characteristics of the material itself. Vacancies can increase the number of unsaturated coordination electrons and unsaturated coordination active sites, and reduce the energy barrier of gas molecule adsorption, which is an effective strategy to realize room temperature sensing.

[0003] Ammonia, as a basic gas for regulating atmospheric balance, also has a wide range of applications in the fields of electronics, food processing and chemistry. However, the current generation of ammonia sensors is plagued by some limitations, including slow response rate, challenges in achieving rapid recovery at ambient temperature, and insufficient humidity resistance, which have caused significant limitations to its practical application. Therefore, exploring high-performance ammonia sensors with room temperature rapid response and high humidity resistance has important practical significance for carbon neutrality and disease warning.

[0004] For a material, the difficulty of preparation process, cost, yield and other factors are necessary conditions for determining whether it can be mass-produced and whether it can be widely applied. However, so far, the defect regulation methods of SnS2 materials reported have the disadvantages of high cost, high operation requirement and insufficient regulation. The regulation method of the present research greatly solves these shortcomings and improves the development speed of SnS2 from laboratory to industrial production. SUMMARY

[0005] In view of the deficiencies of the prior art, a first object of the present application is to provide a preparation method of Sv-SnS2 material based on glucose reduction, the preparation method of the present application improves the concentration of S vacancies in the SnS2 system, improves the electronic structure, improves the response / recovery performance of the gas sensor, and obtains excellent gas selectivity, the preparation method of the present application has low cost, simple operation, high yield, and the prepared Sv-SnS2 material has large specific surface area.

[0006] A second object of the present application is to provide the Sv-SnS2 material prepared by the above preparation method.

[0007] A third object of the present application is to provide the application of the Sv-SnS2 material prepared by the above preparation method. The Sv-SnS2 material is used for preparing an ammonia gas sensor, the prepared ammonia gas sensor has small volume, low power consumption, fast response and recovery speed at room temperature, excellent application conditions, and good detection performance for ammonia gas.

[0008] In order to achieve the above objects, the present application adopts the following technical solutions:

[0009] The present application provides a preparation method of Sv-SnS2 material based on glucose reduction, a solution containing tin source and thioacetamide is subjected to first hydrothermal reaction to obtain SnS2 powder, the SnS2 powder, water, cationic surfactant and glucose are mixed to obtain a suspension, and then the mixed solution is obtained by stirring, and the mixed solution is subjected to second hydrothermal reaction to obtain Sv-SnS2 material.

[0010] The preparation method of the present application first uses tin source and thioacetamide as raw materials, obtains SnS2 powder through first hydrothermal reaction, then obtains Sv-SnS2 material by mixing SnS2 powder, water, cationic surfactant and glucose solution through second hydrothermal reaction, because SnS2 is difficult to dissolve in water, the addition of cationic surfactant enhances the activity of SnS2 in water, and improves the ionization degree of SnS2 in water; SnS2 and glucose are decomposed into corresponding organic acids at high temperature, and S vacancies are generated by ionization of SnS2 and S 2- The combination reduces the content of S in the system, generates S vacancies, and the electronic structure of the reduced Sv-SnS2 enhances the activity of carriers in the system and improves the electron transport efficiency, which is beneficial to the response and recovery of the gas sensor.

[0011] In a preferred embodiment, the solvent in the solution containing tin source and thioacetamide is anhydrous ethanol.

[0012] In the present application, anhydrous ethanol is used as the solvent for the preparation of SnS2 powder, which can form nanospherical flower-like SnS2 powder, and the nanospherical flower-like morphology can be maintained after the second hydrothermal reaction of the raw material, and the generated spherulitic Sv-SnS2 has a large specific surface area, and the space stacking structure is beneficial to the adsorption of gas, which is very helpful to the performance improvement of the sensor.

[0013] The inventors found that the solvent directly affects the generation of nanospherical flower-like morphology, and if water is used as the solvent, a laminar structure of Sv-SnS2 will be obtained, which will reduce the specific surface area of Sv-SnS2.

[0014] In a preferred embodiment, the tin source is selected from tin tetrachloride pentahydrate (SnCl4·5H2O).

[0015] In a preferred embodiment, the concentration of the tin source in the solution containing the tin source and thioacetamide is 0.02-0.09 mol / L, preferably 0.04-0.08 mol / L, and further preferably 0.061-0.062 mol / L.

[0016] In a preferred embodiment, the molar ratio of the tin source to thioacetamide in the solution containing the tin source and thioacetamide is 1:1.8-2.2, preferably 1.9-2.1.

[0017] In a preferred embodiment, the preparation process of the solution containing the tin source and thioacetamide is as follows: the tin source is dissolved in anhydrous ethanol, and then thioacetamide is added, and the solution is stirred at a stirring speed of 600-800 r / min at room temperature for 0.5-0.8 h to obtain a colorless transparent solution. Then the solution containing the tin source and thioacetamide is transferred to a polytetrafluoroethylene liner for hydrothermal reaction.

[0018] In a preferred embodiment, the temperature of the first hydrothermal reaction is 180-185℃, and the time of the hydrothermal reaction is 16-16.5 h.

[0019] In a preferred embodiment, after the first hydrothermal reaction is completed, the obtained reaction liquid is centrifuged, and the obtained solid phase is vacuum dried to obtain SnS2 powder.

[0020] Further preferably, the centrifugal speed is 5000-5500 r / min.

[0021] Further preferably, the temperature of the vacuum drying is 60-80℃, and the time of the vacuum drying is 8-8.5 h.

[0022] In actual operation, anhydrous ethanol is used for centrifugation 3-4 times at room temperature, and the yellow precipitate is dried in a vacuum drying oven.

[0023] Preferably, the concentration of SnS2 powder in the mixed solution is 0.01-0.03 mol / L, preferably 0.021-0.023 mol / L.

[0024] The inventors have found that the concentration of the precursor has an effect on the generated SnS2, and the concentration of the original S vacancies in the SnS2 generated by different concentrations of the precursor is different, and the performance of the final S v-SnS2 material is optimal when the concentration is controlled within the above range.

[0025] Preferably, the cationic surfactant is hexadecyl trimethyl ammonium bromide (CTAB).

[0026] Preferably, in the mixed solution, the molar ratio of SnS2 powder to cationic surfactant is 1:0.01-1.5, preferably 0.8-1.2, and further preferably 0.99-1.01. The inventors have found that the amount of the cationic surfactant is related to the degree of electrolysis of the SnS2 system, and too much will cause the degree of electrolysis to be too large, which may lead to the generation of other substances; and too little may not be enough to enhance the activity of SnS2 in water, and the ionization is insufficient.

[0027] Preferably, in the mixed solution, the molar ratio of SnS2 powder to C6H 12 O6 is 1:0.01-2, preferably 0.2-1.2, and further preferably 0.5-1.02. The inventors have found that glucose is a key reagent in the entire reduction process and is directly related to the concentration of defects, and the amount of glucose needs to be effectively controlled, if the amount of glucose is too small, the S defects are generated too little, and the performance improvement is limited, and if the amount of glucose is excessive, the SnS2 will be eroded too much, which directly changes the original chemical structure and also leads to a decrease in performance.

[0028] Preferably, the suspension is obtained by sequentially adding SnS2 powder, cationic surfactant, and glucose into water.

[0029] Preferably, the stirring rate is 600-800 r / min, and the stirring time is 2-2.2 h.

[0030] After SnS2 powder, cationic surfactant, and glucose are added to water according to the designed composition, stirring is crucial, because stirring not only makes the materials mix more uniformly, but more importantly, stirring can enhance the degree of ionization of SnS2, and a faster stirring speed within the scope of the present application will have an intercalation process, which will cause atomic layer peeling, so that the two-dimensional material is thinned, and the gas sensitivity response is further improved.

[0031] Preferably, the temperature of the second hydrothermal reaction is 180-185℃, and the time of the second hydrothermal reaction is 12h-12.5h. During the second hydrothermal reaction, the temperature is controlled within the range of the present application, and glucose is decomposed into corresponding organic acid at high temperature, taking away S in the system 2- S defects are generated. Too low temperature will result in that glucose cannot be decomposed, and too high temperature will possibly change the original structure of SnS2.

[0032] Preferably, after the second reaction is completed, the obtained reaction solution is centrifuged, and the obtained solid phase is vacuum dried to obtain the Sv-SnS2 material.

[0033] Further preferably, the centrifugal speed is 5000-5500r / min.

[0034] Further preferably, the temperature of the vacuum drying is 60-80℃, and the time of the vacuum drying is 8-8.5h.

[0035] In actual operation, after the reaction is completed, the reaction solution is taken out, and after it is cooled to room temperature, it is centrifuged 3-4 times with deionized water and anhydrous ethanol solution to obtain a brown precipitate, which is then dried in a vacuum drying box.

[0036] The present application also provides the Sv-SnS2 material prepared by the above preparation method.

[0037] The present application also provides the application of the Sv-SnS2 material prepared by the above preparation method, and the Sv-SnS2 material is used for preparing an ammonia gas sensor.

[0038] Preferably, the preparation method of the ammonia gas sensor is as follows: the Sv-SnS2 material is ground for 8-10 min to obtain a powdery material, anhydrous ethanol is added dropwise into the powdery material, and then the powdery material is ground for 8-10 min to obtain a slurry, the slurry is coated on an Al2O3 substrate with Au metal interdigital electrodes, and aging treatment is performed to obtain the ammonia gas sensor; the temperature of the aging treatment is 60-80℃, and the time of the aging treatment is 2-3h.

[0039] Aging is a necessary step for a resistance type gas sensor, and plays a role in stabilizing the baseline resistance, so that the signal-to-noise ratio in the test process is small; the aging temperature and time are controlled within the range of the present application, and the performance of the finally obtained ammonia gas sensor is optimal; if the aging conditions are unreasonable, the response value of the sensor will be unstable, and the aging time process will have a risk of oxidation of SnS2, which will reduce S defects in the system.

[0040] In actual operation, the Sv-SnS2 material is put into a mortar and ground for 8-10 minutes to obtain a powdery material; then, anhydrous ethanol is dropped into the mortar, and the mortar is ground for another 8-10 minutes to obtain a viscous slurry; a small amount of the slurry is taken with a small brush and uniformly coated on an Al2O3 substrate with Au metal interdigital electrodes, and then the substrate is placed in a 60℃ oven for heating for 2h for aging treatment to obtain an ammonia gas sensor of the ball-flower-shaped Sv-SnS2 nanomaterial.

[0041] Principle and advantage

[0042] The preparation method of the application first takes tin source and thioacetamide as raw materials, obtains SnS2 powder through a first hydrothermal reaction, and then obtains Sv-SnS2 material through a second hydrothermal reaction of a mixed solution containing SnS2 powder, water, cationic surfactant and glucose. 2- The cationic surfactant enhances the activity of SnS2 in water and improves the ionization degree of SnS2 in water. 2- The generated S defects and the reduced Sv-SnS2 through the above-mentioned way enhance the carrier activity and electron transmission efficiency of the system, which is beneficial to the response recovery of the gas sensor.

[0043] Compared with the prior art, the application has at least the following advantages:

[0044] 1. The application realizes the introduction of defects in two-dimensional layered materials by using a liquid phase reduction method, which has the characteristics of environmental protection of raw materials, low production cost and simple preparation process, and is a defect introduction method suitable for large-scale green production.

[0045] 2. The Sv-SnS2 nanomaterial prepared by the application improves the electronic structure of the two-dimensional SnS2 nanomaterial system and overcomes the application limitation of poor inherent properties of metal sulfides at low temperatures. The ammonia gas sensor prepared by using the Sv-SnS2 nanomaterial has a response / recovery time of 13 / 167s under working conditions of 25℃ and 30%RH, has excellent selectivity, and has small size, low power consumption, fast response and recovery speed at room temperature, excellent application conditions and good detection performance for ammonia. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The XRD pattern of the 0.15-SG material obtained in Example 1 of the application.

[0047] Figure 2 The SEM pattern of the 0.15-SG material obtained in Example 1 of the application.

[0048] Figure 3 EPR diagram of the Sv-SnS2 material obtained in Example 1-4 of the present application.

[0049] Figure 4 Response / recovery diagram of the high-performance ammonia sensor prepared in Example 1-4 of the present application.

[0050] Figure 5 Selectivity diagram of the high-performance ammonia sensor obtained in Example 1 of the present application. DETAILED DESCRIPTION

[0051] The present application is further illustrated below through specific examples.

[0052] Example 1

[0053] 1. Preparation of SnS2 powder

[0054] Take 80 mL of ethanol solution, weigh 0.7513 g of tin tetrachloride pentahydrate into the above solution to obtain solution A; then weigh 1.7315 g of thioacetamide into solution A to obtain solution B; solution B is stirred at 500 r / min for 30 min at 25℃ to obtain colorless transparent solution C, then solution C is transferred into a polytetrafluoroethylene liner, and hydrothermal reaction is carried out for 16 h; after the reaction time is completed, the reaction kettle is taken out, and after cooling, yellow precipitate is obtained by centrifugation with anhydrous ethanol at 5000 r / min for 3 times at room temperature, and then dried in a vacuum drying oven at 60℃ for 8 h to obtain D powder, which is SnS2 powder;

[0055] Preparation of Sv-SnS2 material

[0056] Take 50 mL of deionized water, weigh 0.2011 g of D powder to obtain yellow suspension E; then weigh 0.4 g of CTAB into E to obtain yellow precipitate solution F; weigh 0.15 g of glucose reagent (the molar ratio thereof to SnS2 powder is 1:0.763) into F, and then stir the solution at 600 r / min for 2 h to obtain yellow solution, which is then transferred into polytetrafluoroethylene for hydrothermal reaction for 12 h; after the reaction is completed, it is taken out, and after cooling to room temperature, brown precipitate is obtained by centrifugation with deionized water and anhydrous ethanol solution at 5000 r / min for three times, respectively, and then dried in a vacuum drying oven at 60℃ for 8 h; the Sv-SnS2 material is obtained and marked as 0.15-SG material.

[0057] 3. Preparation of ammonia sensor

[0058] The prepared Sv-SnS2 two-dimensional sheet structure material is placed in a mortar and ground for 8-10 minutes to obtain a powder material; then anhydrous ethanol is dripped into the mortar, and the mixture is ground for another 8-10 minutes to obtain a viscous slurry; a small amount of the slurry is taken with a small brush and uniformly coated on an Al2O3 substrate with Au interdigital electrodes, and then the substrate is placed in a 60°C oven for heating for 2 hours for aging treatment to obtain an ammonia gas sensor of the Sv-SnS2 nanomaterial in the shape of a globeflower.

[0059] Example 2

[0060] 1. Preparation of SnS2 powder

[0061] 80 mL of an ethanol solution is measured, 0.7513 g of tin tetrachloride pentahydrate is weighed and dissolved in the solution to obtain solution A; then 1.7315 g of thioacetamide is weighed and dissolved in solution A to obtain solution B; solution B is stirred at 500 r / min for 30 min at 25°C to obtain colorless transparent solution C, which is then transferred to a polytetrafluoroethylene liner for hydrothermal reaction for 16 h; after the reaction time is completed, the reaction kettle is taken out, and after cooling, the yellow precipitate is obtained by centrifugation with anhydrous ethanol at 5000 r / min for 3 times at room temperature, and then dried in a vacuum drying oven at 60°C for 8 h to obtain D powder, which is SnS2 powder.

[0062] 2. Preparation of Sv-SnS2 material

[0063] 50 mL of deionized water is measured, 0.2011 g of D powder is weighed to obtain yellow suspension E; then 0.4 g of CTAB is weighed and added to E to obtain yellow precipitate solution F; 0.05 g of glucose reagent (with a molar ratio of 1:0.255 to SnS2 powder) is weighed and added to F, and the solution is stirred at 600 r / min for 2 h to obtain a yellow solution, which is then transferred to a polytetrafluoroethylene liner for hydrothermal reaction for 12 h; after the reaction is completed, the solution is taken out and cooled to room temperature, and then centrifuged with deionized water and anhydrous ethanol solution at 5000 r / min for 3 times respectively to obtain a brown precipitate, which is then dried in a vacuum drying oven at 60°C for 8 h; and Sv-SnS2 material is obtained, which is marked as 0.05-SG material.

[0064] 3. Preparation of ammonia gas sensor

[0065] The prepared Sv-SnS2 two-dimensional sheet structure material is placed in a mortar and ground for 8-10 minutes to obtain a powder material; then anhydrous ethanol is dripped into the mortar, and the mixture is ground for another 8-10 minutes to obtain a viscous slurry; a small amount of the slurry is taken with a small brush and uniformly coated on an Al2O3 substrate with Au interdigital electrodes, and then the substrate is placed in a 60°C oven for heating for 2 hours for aging treatment to obtain an ammonia gas sensor of the Sv-SnS2 nanomaterial in the shape of a globeflower.

[0066] Example 3

[0067] 1. Preparation of SnS2 powder

[0068] Take 80 mL of ethanol solution, weigh 0.7513 g of tin tetrachloride pentahydrate and dissolve it in the above solution to obtain solution A; then weigh 1.7315 g of thioacetamide and dissolve it in solution A to obtain solution B; solution B is stirred at 500 r / min for 30 min at 25℃ to obtain colorless transparent solution C, then solution C is transferred to a polytetrafluoroethylene liner and hydrothermal reaction is carried out for 16 h; after the reaction time is completed, the reaction kettle is taken out, and after cooling, yellow precipitate is obtained by centrifugation with anhydrous ethanol at 5000 r / min for 3 times at room temperature, and then dried in a vacuum drying box at 60℃ for 8 h to obtain D powder, which is SnS2 powder;

[0069] 2. Preparation of Sv-SnS2 material

[0070] Take 50 mL of deionized water, weigh 0.2011 g of D powder to obtain yellow suspension E; then weigh 0.4 g of CTAB and add it to E to obtain yellow precipitate solution F; then weigh 0.1 g of glucose reagent (the molar ratio of which to SnS2 powder is 1:0.509) and add it to F, and then stir the solution at 600 r / min for 2 h to obtain a yellow solution, which is then transferred to a polytetrafluoroethylene liner for hydrothermal reaction for 12 h; after the reaction is completed, it is taken out and cooled to room temperature, and then centrifuged with deionized water and anhydrous ethanol solution at 5000 r / min for 3 times respectively to obtain brown precipitate, which is then placed in a vacuum drying box and dried at 60℃ for 8 h; Sv-SnS2 material is obtained, which is marked as 0.1-SG material.

[0071] 3. Preparation of ammonia gas sensor

[0072] Put the above prepared Sv-SnS2 two-dimensional sheet structure material into a mortar and grind for 8-10 minutes to obtain a powder-like material; then add anhydrous ethanol to the mortar and grind for another 8-10 minutes to obtain a viscous slurry; use a small brush to take a small amount of the slurry and evenly coat it on an Al2O3 substrate with Au interdigital electrodes, and then place it in a 60℃ oven for 2 h for aging treatment to obtain an ammonia gas sensor of Sv-SnS2 ball-flower-like nanomaterial.

[0073] Example 4

[0074] Preparation of SnS2 powder

[0075] Take 80 mL of ethanol solution, weigh 0.7513 g of tin tetrachloride pentahydrate into the above solution to obtain solution A; then weigh 1.7315 g of thioacetamide into solution A to obtain solution B; solution B is stirred at 500 r / min for 30 min at 25℃ to obtain colorless transparent solution C, then solution C is transferred into a polytetrafluoroethylene liner, and hydrothermal reaction is carried out for 16 h; after the reaction is completed, the reaction kettle is taken out, and after cooling, yellow precipitate is obtained by centrifugation with anhydrous ethanol at 5000 r / min for 3 times at room temperature, and then dried in a vacuum drying box at 60℃ for 8 h to obtain D powder, which is SnS2 powder;

[0076] 2. Preparation of Sv-SnS2 material

[0077] Take 50 mL of deionized water, weigh 0.2011 g of D powder to obtain yellow suspension E; then weigh 0.4 g of CTAB into E to obtain yellow precipitate solution F; then weigh 0.2 g of glucose (the molar ratio of glucose to SnS2 powder is 1:1.018) glucose reagent into F, and then stir the solution at 600 r / min for 2 h to obtain a yellow solution, which is then transferred into a polytetrafluoroethylene liner for hydrothermal reaction for 12 h; after the reaction is completed, the solution is taken out, and after cooling to room temperature, brown precipitate is obtained by centrifugation with deionized water and anhydrous ethanol solution at 5000 r / min for 3 times, respectively, and then dried in a vacuum drying box at 60℃ for 8 h; and the Sv-SnS2 material is obtained and marked as 0.2-SG material.

[0078] 3. Preparation of ammonia gas sensor

[0079] The above-prepared Sv-SnS2 two-dimensional sheet structure material is placed in a mortar and ground for 8-10 minutes to obtain a powder material; then anhydrous ethanol is added dropwise into the mortar, and the mixture is ground for another 8-10 minutes to obtain a viscous slurry; a small amount of the slurry is taken with a small brush and uniformly coated on an Al2O3 substrate with Au interdigital electrodes, and then the substrate is placed in a 60℃ oven for aging treatment for 2 h to obtain an ammonia gas sensor of the Sv-SnS2 ball-flower-shaped nanomaterial.

[0080] Performance detection of the example

[0081] Figure 1 The XRD pattern of the 0.15-SG material obtained in Example 1 can be seen from Figure 1 , and the characteristic peaks correspond to the PDF (JCPDS 23-0677) card perfectly, indicating the successful preparation of the sample. The 2θ of 15.02, 28.2 and 32.1 correspond to the (001), (100) and (101) crystal planes of SnS2, respectively.

[0082] Figure 2SEM image of 0.15-SG material obtained in Example 1. Figure 2 It can be seen that the 0.15-SG still has a nanospherical flower morphology as a whole, and there is an erosion phenomenon at the edge part, and a large number of dangling bonds exist in the eroded edge, which is beneficial to improve the activity of the SnS2 basal plane and greatly helps to improve the performance of the gas sensor.

[0083] Figure 3 EPR images of Sv-SnS2 materials obtained in Examples 1-4 and SnS2 powder in Example 1. Figure 3 It can be seen from the EPR image that a strong signal is exhibited at g = 2.003, which confirms that there are abundant sulfur vacancies therein. Figure 3 It can be seen from the EPR image that the signal intensity exhibited by different glucose addition amounts is different, indicating that the amount of glucose plays a decisive role in the defect concentration, and the concentration of S vacancies in the 0.15-GS sample is the highest.

[0084] Figure 4 Response / recovery images of high-performance ammonia gas sensors obtained in Examples 1-4. Figure 4 It can be seen from the EPR image that a strong signal is exhibited at g = 2.003, which confirms that there are abundant sulfur vacancies therein. Figure 4 It can be seen from the EPR image that the signal intensity exhibited by different glucose addition amounts is different, indicating that the amount of glucose plays a decisive role in the defect concentration, and the concentration of S vacancies in the 0.15-GS sample is the highest.

[0085] Figure 5 Selectivity image of the high-performance ammonia gas sensor prepared from the 0.15-SG material obtained in Example 1. Figure 5 It can be seen from the EPR image that a strong signal is exhibited at g = 2.003, which confirms that there are abundant sulfur vacancies therein.

[0086] Comparative Example 1

[0087] 80 mL of an ethanol solution was measured, 0.753 g of tin tetrachloride pentahydrate was weighed and dissolved in the above solution to obtain solution A; then 1.7315 g of thioacetamide was weighed and dissolved in solution A to obtain solution B; solution B was stirred at 500 r / min for 30 min at 25 DEG C to obtain colorless transparent solution C, and then solution C was transferred into a polytetrafluoroethylene liner, and hydrothermal reaction was carried out for 16 h; after the reaction time was completed, the reaction kettle was taken out, and after cooling, yellow precipitate was obtained by centrifugation with anhydrous ethanol at room temperature at 5000 r / min for 3 times, and then dried in a vacuum drying oven at 60 DEG C for 8 h to obtain D powder.

[0088] Take 50 mL of deionized water, weigh 0.2011 g of D powder to obtain yellow suspension E; then weigh 0.1 g of CTAB and add it to E to obtain yellow precipitate solution F; weigh 0.15 g of glucose reagent and add it to F, then stir the solution at 200 r / min for 1 h to obtain a yellow solution, which is then transferred to a polytetrafluoroethylene inner container for hydrothermal reaction for 12 h; after the reaction is completed, the reaction kettle is taken out and cooled to room temperature, and then centrifuged with deionized water and anhydrous ethanol solution at 5000 r / min for three times to obtain a brown precipitate, which is then placed in a vacuum drying oven at 60°C for 8 h;

[0089] The above prepared Sv-SnS2 two-dimensional sheet structure material is placed in a mortar and ground for 8-10 minutes to obtain a powder material; then anhydrous ethanol is added to the mortar and ground for another 8-10 minutes to obtain a viscous slurry; a small amount of the slurry is taken with a small brush and uniformly coated on an Al2O3 substrate with Au interdigital electrodes, and then placed in a 60°C oven for 2 h for aging treatment to obtain an ammonia gas sensor of Sv-SnS2 ball-flower-shaped nanomaterial.

[0090] The stirring speed in the second step of the reduction process in Comparative Example 1 is too slow, and the final ammonia gas sensor is significantly weaker than that of Example 1, because the stirring process can make the reagents fully combine, which plays a key role in the ionization of SnS2 and improves the hierarchy of S vacancy formation. Moreover, the addition of CTAB and the subsequent stirring can play an intercalation role for two-dimensional layered materials, increasing the interlayer spacing of two-dimensional materials. Both of these aspects can help improve the gas sensing performance of the gas sensor.

[0091] Comparative Example 2

[0092] Take 80 mL of ethanol solution, weigh 0.753 g of tin tetrachloride pentahydrate and dissolve it in the above solution to obtain solution A; then weigh 1.7315 g of thioacetamide and dissolve it in solution A to obtain solution B; solution B is stirred at 500 r / min for 30 min at 25°C to obtain colorless transparent solution C, which is then transferred to a polytetrafluoroethylene inner container for hydrothermal reaction for 16 h; after the reaction time is completed, the reaction kettle is taken out and cooled, and then centrifuged with anhydrous ethanol at room temperature at 5000 r / min for 3 times to obtain a yellow precipitate, which is dried in a vacuum drying oven at 60°C for 8 h to obtain D powder;

[0093] 50 mL of deionized water was measured, 0.2011 g of D powder was weighed to obtain yellow suspension E; then 0.1 g of CTAB was weighed and added to E to obtain yellow precipitate solution F; 0.15 g of glucose reagent was weighed and added to F, and the solution was stirred at 600 r / min for 2 h to obtain a yellow solution, which was then transferred to a polytetrafluoroethylene autoclave for hydrothermal reaction for 12 h; after the reaction was completed, it was taken out and cooled to room temperature, and then centrifuged with deionized water and anhydrous ethanol solution at 5000 r / min for three times to obtain a brown precipitate, which was then placed in a vacuum drying oven at 60°C for 8 h;

[0094] The above prepared Sv-SnS2 two-dimensional sheet structure material was placed in a mortar and ground for 8-10 minutes to obtain a powdery material; then anhydrous ethanol was added dropwise to the mortar, and the mixture was ground for another 8-10 minutes to obtain a viscous slurry; a small amount of the slurry was taken with a small brush and uniformly coated on an Al2O3 substrate with Au metal interdigital electrodes, and then the substrate was placed in a 90°C oven for aging treatment for 5 h to obtain an ammonia gas sensor of the ball-flower-shaped Sv-SnS2 nanomaterial.

[0095] The ammonia gas sensor obtained in this example was significantly reduced compared to Example 1, because the aging temperature and time of the sensor in Comparative Example 2 were very critical. During the aging process, there was a risk of oxidation of the gas sensor rich in defects, and too high a temperature or too long an aging time could affect the content of S defects, which had an impact on the activity of the sensor sensitive layer at room temperature.

[0096] Finally, it should be noted that the above examples are only specific embodiments of the present application. Obviously, the present application is not limited to the above examples, and many variations can be made. All variations that can be directly derived or inferred from the disclosure of the present application by those of ordinary skill in the art should be considered within the scope of the present application.

Claims

1. A method for preparing glucose reduction-based Sv-SnS2 material, characterized in that: The solution containing a tin source and thioacetamide is subjected to a first hydrothermal reaction to obtain SnS2 powder, the SnS2 powder, water, a cationic surfactant and glucose are mixed to obtain a suspension, and then the mixed solution is obtained by stirring, and the mixed solution is subjected to a second hydrothermal reaction to obtain the Sv-SnS2 material.

2. The method according to claim 1, wherein the method is characterized by: The solvent in the solution containing a tin source and thioacetamide is anhydrous ethanol.

3. The preparation method of the Sv-SnS2 material based on glucose reduction according to claim 1 or 2, characterized in that: the tin source is selected from tin tetrachloride pentahydrate; the concentration of the tin source in the solution containing a tin source and thioacetamide is 0.02-0.09 mol / L; the molar ratio of the tin source to thioacetamide in the solution containing a tin source and thioacetamide is 1:1.8-2.2; the preparation process of the solution containing a tin source and thioacetamide is as follows: the tin source is dissolved in anhydrous ethanol, and then thioacetamide is added, and a colorless transparent solution is obtained by stirring at a stirring speed of 600-800 r / min at room temperature for 0.5-0.8 h.

4. The preparation method of the Sv-SnS2 material based on glucose reduction according to claim 1 or 2, characterized in that: the temperature of the first hydrothermal reaction is 180-185 ℃, and the time of the hydrothermal reaction is 16-16.5 h; after the first hydrothermal reaction is completed, the obtained reaction solution is centrifuged, the obtained solid phase is vacuum dried to obtain SnS2 powder; the centrifugal speed is 5000-5500 r / min; the vacuum drying temperature is 60-80 ℃, and the vacuum drying time is 8-8.5 h.

5. The preparation method of the Sv-SnS2 material based on glucose reduction according to claim 1, characterized in that: the concentration of the SnS2 powder in the mixed solution is 0.01-0.03 mol / L.

6. The preparation method of the Sv-SnS2 material based on glucose reduction according to claim 1, characterized in that: the cationic surfactant is CTAB; the molar ratio of the SnS2 powder to the cationic surfactant in the mixed solution is 1:0.01-1.5; In the mixed solution, the molar ratio of SnS2 powder: C6H 12 O6 = 1:0.01 - 2.

7. The method according to claim 1, wherein the method is characterized by: the suspension is obtained by sequentially adding the SnS2 powder, the cationic surfactant and the glucose into water; the stirring speed is 600-800 r / min, and the stirring time is 2-2.2 h.

8. The method of claim 1, wherein the method is a method of preparing a glucose-reduction-based Sv-SnS2 material. the temperature of the second hydrothermal reaction is 180-185 ℃, and the time of the second hydrothermal reaction is 12 h-12.5 h; after the second reaction is completed, the obtained reaction solution is centrifuged, and the obtained solid phase is vacuum dried to obtain the Sv-SnS2 material; the centrifugal speed is 5000-5500 r / min; the vacuum drying temperature is 60-80 ℃, and the vacuum drying time is 8-8.5 h.

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