A covalently bonded tin sulfide / zinc indium sulfide composite material, a preparation method thereof, and an application thereof

Abstract

The present invention discloses a covalently bonded tin sulfide / zinc indium sulfide composite material, which consists of two-dimensional zinc indium sulfide nanosheets supported on one-dimensional tin sulfide nanoribbons. The tin atoms in the tin sulfide nanoribbons are covalently bonded to the sulfur atoms in the zinc indium sulfide nanosheets. This composite material can be used as a photocatalyst in photocatalytic water splitting for hydrogen production. The preparation method disclosed in the present invention includes using water-soluble tin source and sulfur source as raw materials, performing hydrothermal reaction in an alkaline aqueous solution to obtain one-dimensional tin sulfide nanoribbons, adding them to the precursor solution of zinc indium sulfide, and heating and stirring to react to obtain the covalently bonded tin sulfide / zinc indium sulfide composite material. The present invention has excellent visible light response ability, promotes the rapid separation and transfer of photo-generated charges, and significantly improves the photocatalytic water splitting performance for hydrogen production. The preparation method of the present invention has a simple process, easily available raw materials, and is suitable for large-scale application.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of tin sulfide / indium zinc sulfide composites, and particularly to a covalently bonded tin sulfide / indium zinc sulfide composite material, its preparation method and application. Background Art

[0002] Driven by sunlight, using semiconductor materials as catalysts to decompose water into hydrogen is a green and effective hydrogen production technology, and it is also one of the most promising ways to convert solar energy into chemical energy. Semiconductor metal sulfides are an important type of materials for photocatalytic water splitting to produce hydrogen. Among them, indium zinc sulfide, as a photocatalyst with a two-dimensional layered structure, has attracted extensive attention due to its simple preparation method, good visible light absorption ability and suitable energy band structure. However, the activity of pure indium zinc sulfide for photocatalytic hydrogen production is still severely limited by the rapid recombination of its photogenerated electrons and holes. Tin sulfide has excellent optoelectronic properties, such as a wide light absorption range from visible light to near-infrared light and a high electron migration rate. How to compound tin sulfide and indium zinc sulfide to form an effective heterojunction is an important issue to improve its catalytic performance. Summary of the Invention

[0003] Aiming at the defects of the above-mentioned prior art, the present invention provides a covalently bonded tin sulfide / indium zinc sulfide composite material, which overcomes the problems of rapid recombination of photogenerated carriers, loose formation of heterointerfaces and low catalytic efficiency in existing catalytic materials. The present invention also provides a preparation method and an application of the covalently bonded tin sulfide / indium zinc sulfide composite material.

[0004] The technical solution of the present invention is as follows: A covalently bonded tin sulfide / indium zinc sulfide composite material includes two-dimensional indium zinc sulfide nanosheets and one-dimensional tin sulfide nanoribbons. The two-dimensional indium zinc sulfide nanosheets are loaded on the one-dimensional tin sulfide nanoribbons, and the tin atoms in the tin sulfide nanoribbons are covalently bonded to the sulfur atoms in the indium zinc sulfide nanosheets.

[0005] Another technical solution of the present invention is: A preparation method of a covalently bonded tin sulfide / indium zinc sulfide composite material includes the steps of:

[0006] (1) Using a water-soluble tin source and a sulfur source as raw materials, performing a hydrothermal reaction in an alkaline aqueous solution. After the reaction ends, washing and vacuum drying are carried out to prepare one-dimensional tin sulfide nanoribbons;

[0007] (2) Adding the one-dimensional tin sulfide nanoribbons obtained in step (1) to a precursor solution of indium zinc sulfide, heating and stirring for reaction. After the reaction ends, washing and vacuum drying are carried out to prepare a covalently bonded tin sulfide / indium zinc sulfide composite material.

[0008] Further, the tin source is selected from one of stannous chloride, stannous sulfate and stannous acetate; the sulfur source is selected from one of thioacetamide, thiourea, sodium thiosulfate and ammonium sulfide; the alkaline aqueous solution is selected from one of urea aqueous solution, sodium hydroxide aqueous solution and sodium carbonate aqueous solution.

[0009] Further, in the step (1), the molar ratio of the tin source to the sulfur source is 1:(10 - 30); the molar concentration of the alkaline aqueous solution is 0.2 - 0.5 mol / L.

[0010] Further, in the step (1), the temperature of the hydrothermal reaction is 150 - 200 °C, and the reaction time is 12 - 20 h.

[0011] Further, the precursor solution of indium zinc sulfide is obtained by dissolving zinc chloride, indium chloride tetrahydrate and thioacetamide in a mixed solvent of glycerol and water. The molar ratio of zinc chloride, indium chloride tetrahydrate and thioacetamide is 1:(2 - 5):(3 - 8). The pH value of the precursor solution of indium zinc sulfide is adjusted to 1 - 4 with dilute hydrochloric acid, and the volume ratio of glycerol to water is 1:(3 - 10).

[0012] Further, the one-dimensional stannous sulfide nanobelts are added in the precursor solution of indium zinc sulfide in a mass ratio of 5% - 20% in the covalently bonded stannous sulfide / indium zinc sulfide composite material, preferably 10% - 15%.

[0013] Further, the temperature of the heating and stirring reaction is 50 - 80 °C, and the reaction time is 1 - 5 h.

[0014] Further, in the steps (1) and (2), the product is washed 3 - 6 times with water and ethanol respectively during washing, and vacuum drying is carried out at 50 - 80 °C for 10 - 20 h.

[0015] Another technical solution of the present invention is the application of a covalently bonded stannous sulfide / indium zinc sulfide composite material as a photocatalyst in photocatalytic water splitting for hydrogen production.

[0016] The advantages of the present invention compared with the prior art are as follows:

[0017] (1) The covalently bonded stannous sulfide / indium zinc sulfide composite material of the present invention is a covalent heterojunction interface formed by in-situ growth of two-dimensional indium zinc sulfide nanosheets on one-dimensional stannous sulfide nanobelts and bonded by Sn–S covalent bonds, overcoming the problem of loose interface contact in heterojunction catalytic materials. The built-in electric field at the interface promotes the effective separation and rapid transfer of photo-generated electrons and holes through the formed Sn–S covalent bonds, significantly improving the performance of photocatalytic water splitting for hydrogen production.

[0018] (2) The morphological structure of the covalently bonded tin sulfide / zinc indium sulfide composite material of the present invention is a one-dimensional / two-dimensional structure. The advantages of this structure are as follows: on the one hand, it can further improve the separation efficiency of photo-generated carriers by utilizing the fast and long-distance charge transport characteristics of one-dimensional structure materials; on the other hand, the introduction of one-dimensional tin sulfide nanoribbons inhibits the self-aggregation of two-dimensional zinc indium sulfide nanosheets, which helps to expose abundant reactive sites.

[0019] (3) The covalently bonded tin sulfide / zinc indium sulfide composite material of the present invention is a catalytic material with strong visible light response ability, high photocatalytic water splitting hydrogen production effect, stable performance, and can be reused multiple times, and has good application prospects in the new energy field.

[0020] (4) The preparation method of the covalently bonded tin sulfide / zinc indium sulfide composite material of the present invention is simple, the required raw materials are easy to obtain, and the operation is simple, which is suitable for large-scale industrial applications. Brief Description of the Drawings

[0021] Figure 1 It is a scanning electron microscope (SEM) image of the tin sulfide nanoribbons obtained in Example 1.

[0022] Figure 2 It is a transmission electron microscope (TEM) image of the tin sulfide nanoribbons obtained in Example 1.

[0023] Figure 3 It is an SEM image of the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 1.

[0024] Figure 4 It is a TEM image of the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 1.

[0025] Figure 5 It is a high-resolution X-ray photoelectron spectroscopy (XPS) spectrum of tin elements in the tin sulfide nanoribbons and the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 1.

[0026] Figure 6 It is an SEM image of the tin sulfide nanoribbons obtained in Example 2.

[0027] Figure 7 It is an SEM image of the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 2.

[0028] Figure 8 It is an XPS spectrum of tin elements in the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 2.

[0029] Figure 9SEM image of the tin sulfide nanobelts obtained in Example 3.

[0030] Figure 10 SEM image of the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 3.

[0031] Figure 11 XPS spectrum of tin element in the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 3.

[0032] Figure 12 SEM image of the flower-like zinc indium sulfide obtained in the comparative example.

[0033] Figure 13 TEM image of the flower-like zinc indium sulfide obtained in the comparative example.

[0034] Figure 14 Effect diagram of photocatalytic water splitting for hydrogen production of the materials prepared from Example 1, the covalently bonded tin sulfide / zinc indium sulfide composite materials with different mass ratios, and Comparative Example 1.

[0035] Figure 15 Effect diagram of photocatalytic water splitting for hydrogen production of the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 1, the physical mixture of tin sulfide nanobelts and flower-like zinc indium sulfide obtained in Comparative Example 2.

[0036] Figure 16 Cyclic effect diagram of photocatalytic water splitting for hydrogen production of the covalently bonded tin sulfide / zinc indium sulfide composite material obtained in Example 1. Detailed implementation manners

[0037] The present invention will be further described below in conjunction with the examples, but it is not intended to limit the present invention.

[0038] Example 1

[0039] Preparation of one-dimensional tin sulfide nanobelts, the specific steps are as follows:

[0040] First, 10 mmol of thioacetamide was added to 40 mL of an aqueous urea solution (0.35 mol / L), and stirred until completely dissolved to obtain a homogeneous solution. Then, 0.6 mmol of stannous chloride dihydrate was added to the above solution, and stirring was continued for 30 min. Finally, the obtained mixed solution was transferred to a 50 mL autoclave, and the autoclave was placed in a forced-air drying oven at 170 °C for reaction for 16 h. After the reaction was completed and naturally cooled to room temperature, the product was washed 3 times with water and ethanol respectively, and finally dried in a vacuum drying oven at 60 °C for 12 h to obtain one-dimensional tin sulfide nanobelts.

[0041] AppendixFigure 1 and Figure 2 are the SEM and TEM images of the tin sulfide nanobelts prepared in Example 1, respectively. It can be seen from the images that the prepared tin sulfide nanobelts exhibit a smooth-surfaced one-dimensional belt-like structure.

[0042] The preparation of covalently bonded tin sulfide / zinc indium sulfide composites is as follows:

[0043] First, 32 mL of water (the pH value is adjusted to 2.5 with 0.5 mol / L dilute hydrochloric acid) and 8 mL of glycerol are added to a 150 mL round-bottom flask, and ultrasonic treatment is carried out for 5 min to obtain a homogeneous solution. Then, 1 mmol of zinc chloride, 2 mmol of indium chloride tetrahydrate, and 4 mmol of thioacetamide are successively added to the above solution, and stirring is carried out for 15 min. Next, preferably 14.1 mg of tin sulfide nanobelts are added to the above precursor solution of zinc indium sulfide, and ultrasonic dispersion is carried out for 15 min to obtain a homogeneous suspension, which is then placed in an oil bath at 80 °C and reacted for 2 h. After the reaction is completed and naturally cooled to room temperature, the product is washed three times with water and ethanol respectively, and finally dried in a vacuum drying oven at 60 °C for 12 h to obtain a series of tin sulfide / zinc indium sulfide composites, where the mass ratio of one-dimensional tin sulfide nanobelts in the tin sulfide / zinc indium sulfide composites is 15%.

[0044] Appendix Figure 3 and Figure 4 are the SEM and TEM images of the covalently bonded tin sulfide / zinc indium sulfide composites prepared in Example 1, respectively. It can be seen from the images that two-dimensional zinc indium sulfide nanosheets are uniformly and tightly loaded on the surface of one-dimensional tin sulfide nanobelts, showing a one-dimensional / two-dimensional structural feature.

[0045] Appendix Figure 5 is the high-resolution XPS spectrum of tin element in the tin sulfide nanobelts and covalently bonded tin sulfide / zinc indium sulfide composites prepared in Example 1. It can be seen from the figure that compared with the tin sulfide nanobelts, the tin sulfide / zinc indium sulfide composites have an obvious characteristic peak at a binding energy of 497.72 eV, corresponding to the mutual bonding of tin atoms in tin sulfide and sulfur atoms in zinc indium sulfide to form an interfacial Sn–S covalent bond.

[0046] Example 2

[0047] The preparation of one-dimensional tin sulfide nanobelts is as follows:

[0048] First, 10 mmol of thioacetamide was added to 40 mL of an aqueous urea solution (0.25 mol / L), and stirred until completely dissolved to obtain a homogeneous solution. Then, 1.0 mmol of stannous chloride dihydrate was added to the above solution, and stirring was continued for 30 min. Finally, the obtained mixed solution was transferred to a 50 mL autoclave, and the autoclave was placed in a forced-air drying oven at 150 °C for reaction for 20 h. After the reaction was completed and naturally cooled to room temperature, the product was washed three times with water and ethanol respectively, and finally dried in a vacuum drying oven at 60 °C for 12 h to obtain one-dimensional stannous sulfide nanobelts.

[0049] Attachment Figure 6 Figure Figure 6 shows the SEM image of the stannous sulfide nanobelts prepared in Example 2. It can be seen from the picture that the prepared stannous sulfide nanobelts exhibit a one-dimensional belt-like structure with a smooth surface.

[0050] The preparation of covalently bonded stannous sulfide / zinc indium sulfide composites is as follows:

[0051] First, 35 mL of water (the pH value was adjusted to 1.5 with 0.5 mol / L dilute hydrochloric acid) and 5 mL of glycerol were added to a 150 mL round-bottom flask, and ultrasonicated for 5 min to obtain a homogeneous solution. Then, 1 mmol of zinc chloride, 3 mmol of indium chloride tetrahydrate, and 6 mmol of thioacetamide were successively added to the above solution, and stirred for 15 min. Next, preferably 14.1 mg of stannous sulfide nanobelts were added to the above precursor solution of zinc indium sulfide, ultrasonicated and dispersed for 15 min to obtain a homogeneous suspension, and then placed in an oil bath at 60 °C for reaction for 5 h. After the reaction was completed and naturally cooled to room temperature, the product was washed three times with water and ethanol respectively, and finally dried in a vacuum drying oven at 70 °C for 16 h to obtain stannous sulfide / zinc indium sulfide composites.

[0052] Attachment Figure 7 Figure Figure 7 shows the SEM image of the covalently bonded stannous sulfide / zinc indium sulfide composites prepared in Example 2. It can be seen from the picture that two-dimensional zinc indium sulfide nanosheets are uniformly and tightly loaded on the surface of one-dimensional stannous sulfide nanobelts, presenting one-dimensional / two-dimensional structural characteristics.

[0053] Attachment Figure 8 Figure Figure 8 shows the high-resolution XPS spectra of tin elements in the stannous sulfide nanobelts and covalently bonded stannous sulfide / zinc indium sulfide composites prepared in Example 2. It can be seen from the figure that the stannous sulfide / zinc indium sulfide composites have an obvious characteristic peak at a binding energy of 497.71 eV, corresponding to the formation of an interfacial Sn–S covalent bond between the tin atoms in stannous sulfide and the sulfur atoms in zinc indium sulfide.

[0054] Example 3

[0055] Preparation of stannous sulfide nanobelts with a one-dimensional structure, the specific steps are as follows:

[0056] First, 15 mmol of thioacetamide was added to 40 mL of an aqueous urea solution (0.45 mol / L), and stirred until completely dissolved to obtain a homogeneous solution. Then, 0.5 mmol of stannous chloride dihydrate was added to the above solution, and stirring was continued for 30 min. Finally, the obtained mixed solution was transferred to a 50 mL high-pressure reactor, and the reactor was placed in a blast drying oven at 200 °C for reaction for 12 h. After the reaction was completed and naturally cooled to room temperature, the product was washed 3 times with water and ethanol respectively, and finally dried in a vacuum drying oven at 60 °C for 12 h to obtain stannous sulfide nanobelts with a one-dimensional structure.

[0057] Appendix Figure 9 SEM image of the stannous sulfide nanobelts prepared in Example 3. It can be seen from the picture that the prepared stannous sulfide nanobelts exhibit a one-dimensional belt-like structure with a smooth surface.

[0058] Preparation of covalently bonded stannous sulfide / zinc indium sulfide composite materials, the specific steps are as follows:

[0059] First, 30 mL of water (pH adjusted to 3.5 with 0.5 mol / L dilute hydrochloric acid) and 3 mL of glycerol were added to a 150 mL round-bottom flask, and ultrasonicated for 5 min to obtain a homogeneous solution. Then, 1 mmol of zinc chloride, 5 mmol of indium chloride tetrahydrate and 8 mmol of thioacetamide were successively added to the above solution, and stirred for 15 min. Then, preferably 14.1 mg of stannous sulfide nanobelts were added to the above precursor solution of zinc indium sulfide, ultrasonicated and dispersed for 15 min to obtain a homogeneous suspension, and then placed in an oil bath at 70 °C for reaction for 3 h. After the reaction was completed and naturally cooled to room temperature, the product was washed 3 times with water and ethanol respectively, and finally dried in a vacuum drying oven at 80 °C for 20 h to obtain stannous sulfide / zinc indium sulfide composite materials.

[0060] Appendix Figure 10 SEM image of the covalently bonded stannous sulfide / zinc indium sulfide composite materials prepared in Example 3. It can be seen from the picture that two-dimensional zinc indium sulfide nanosheets are uniformly and tightly loaded on the surface of one-dimensional stannous sulfide nanobelts, showing one-dimensional / two-dimensional structural characteristics.

[0061] Appendix Figure 11 High-resolution XPS spectra of tin elements in the stannous sulfide nanobelts and covalently bonded stannous sulfide / zinc indium sulfide composite materials prepared in Example 3. It can be seen from the figure that the stannous sulfide / zinc indium sulfide composite materials have an obvious characteristic peak at a binding energy of 497.70 eV, corresponding to the formation of an interfacial Sn–S covalent bond between the tin atoms in stannous sulfide and the sulfur atoms in zinc indium sulfide.

[0062] Comparative Example 1

[0063] The preparation of flower-like indium zinc sulfide is as follows:

[0064] First, 32 mL of water (the pH value is adjusted to 2.5 with 0.5 mol / L dilute hydrochloric acid) and 8 mL of glycerol are added to a 150 mL round-bottom flask, and ultrasonic treatment is carried out for 5 min to obtain a uniform solution. Then, 1 mmol of zinc chloride, 2 mmol of indium chloride tetrahydrate, and 4 mmol of thioacetamide are successively added to the above solution. After stirring for 15 min, it is placed in an oil bath at 80 °C and reacted for 2 h. After the reaction is completed and naturally cooled to room temperature, the product is washed 3 times with water and ethanol respectively, and finally dried in a vacuum drying oven at 60 °C for 12 h to obtain flower-like indium zinc sulfide.

[0065] Appendix Figure 12 and Figure 13 are the SEM and TEM images of the flower-like indium zinc sulfide respectively. It can be seen from the pictures that the prepared indium zinc sulfide is assembled into a flower-like structure by a large number of two-dimensional nanosheets.

[0066] Comparative Example 2

[0067] The preparation of the physical mixture of tin sulfide nanoribbons and flower-like indium zinc sulfide is as follows:

[0068] 14.1 mg of the tin sulfide nanoribbons obtained in Example 1 and 80 mg of the flower-like indium zinc sulfide obtained in Comparative Example 1 are placed in a mortar and ground for 30 min, and no other treatment is required to obtain the physical mixture of the tin sulfide nanoribbons and the flower-like indium zinc sulfide.

[0069] Performance comparison experiment

[0070] Photocatalytic water splitting for hydrogen production is as follows:

[0071] Based on the preparation steps of Example 1, 4.2 mg, 8.9 mg, and 20 mg of tin sulfide nanoribbons are respectively added to the precursor solution of indium zinc sulfide, and then ultrasonic dispersion is carried out for 15 min to obtain a uniform suspension, which is then placed in an oil bath at 80 °C and reacted for 2 h. After the reaction is completed and naturally cooled to room temperature, the product is washed 3 times with water and ethanol respectively, and finally dried in a vacuum drying oven at 60 °C for 12 h to obtain the tin sulfide / indium zinc sulfide composite material, and the mass ratios of the one-dimensional tin sulfide nanoribbons in the tin sulfide / indium zinc sulfide composite material are 5%, 10%, and 20% respectively.

[0072] 10 mg of the one-dimensional tin sulfide nanoribbons obtained in Example 1, the covalently bonded tin sulfide / zinc indium sulfide composites based on 5%, 10%, 15%, and 20% of the mass ratio of Example 1, the flower-like zinc indium sulfide obtained in Comparative Example 1, and the physical mixture of tin sulfide nanoribbons and flower-like zinc indium sulfide obtained in Comparative Example 2 were respectively ultrasonicated and dispersed in 100 mL of an aqueous mixed solution of sodium sulfite (0.35 mol / L) and sodium sulfide (0.25 mol / L), and then stirred for 30 min to obtain a uniform suspension. Then, the above suspension was evacuated for 30 min to remove all air, and at the same time, the temperature of the photocatalytic reaction system was maintained at 10 °C using a condensation circulation system. Finally, a 300 W xenon lamp was used as the light source, and the photocatalytic water splitting reaction was continuously carried out for 5 h under stirring conditions. Samples were taken once every 1 h, and the amount of hydrogen gas generated under illumination was quantitatively detected by a gas chromatograph equipped with a thermal conductivity detector.

[0073] Attached Figure 14 It is the effect diagram of photocatalytic water splitting for hydrogen production of the prepared tin sulfide nanoribbons, flower-like zinc indium sulfide, and covalently bonded tin sulfide / zinc indium sulfide composites with different mass ratios. It can be seen from the figure that the photocatalytic hydrogen production efficiency of the covalently bonded tin sulfide / zinc indium sulfide composites is significantly higher than that of the single tin sulfide material and zinc indium sulfide material.

[0074] Attached Figure 15 It is the effect diagram of photocatalytic water splitting for hydrogen production of the covalently bonded tin sulfide / zinc indium sulfide composite obtained in Example 1 and the physical mixture of tin sulfide nanoribbons and flower-like zinc indium sulfide obtained in Comparative Example 2. It can be seen from the figure that the photocatalytic hydrogen production efficiency of the physical mixture of tin sulfide nanoribbons and flower-like zinc indium sulfide is significantly lower than that of the covalently bonded tin sulfide / zinc indium sulfide composite, indicating that the heterojunction interface forming the Sn–S covalent bond can effectively improve the performance of photocatalytic water splitting for hydrogen production.

[0075] Attached Figure 16 It is the cyclic effect diagram of photocatalytic water splitting for hydrogen production of the covalently bonded tin sulfide / zinc indium sulfide composite obtained in Example 1. It can be seen from the figure that after 4 uses, the material still shows a high hydrogen production, indicating its good cyclic stability and potential application value.

Claims

1. A covalently bonded tin sulfide / indium zinc sulfide composite material, characterized in that: The invention comprises a two-dimensional indium zinc sulfide nanosheet and a one-dimensional tin sulfide nanobelt, wherein the two-dimensional indium zinc sulfide nanosheet is loaded on the one-dimensional tin sulfide nanobelt, and the tin atoms in the tin sulfide nanobelt are bonded to the sulfur atoms in the indium zinc sulfide nanosheet through covalent bonds; the preparation method of the covalently bonded tin sulfide / indium zinc sulfide composite material comprises the steps of: (1) using a water-soluble tin source and a sulfur source as raw materials, conducting a hydrothermal reaction in an alkaline aqueous solution, and after the reaction is completed, washing and vacuum drying to prepare a one-dimensional tin sulfide nanobelt; the alkaline aqueous solution is a urea aqueous solution with a molar concentration of 0.2 to 0.5 mol / L; (2) adding the one-dimensional tin sulfide nanobelt obtained in step (1) to a precursor solution of indium zinc sulfide at a mass ratio of 5% to 20% of the one-dimensional tin sulfide nanobelt in the covalently bonded tin sulfide / indium zinc sulfide composite material, heating and stirring to react, and after the reaction is completed, washing and vacuum drying to prepare a covalently bonded tin sulfide / indium zinc sulfide composite material; the indium zinc sulfide precursor solution is obtained by dissolving zinc chloride, indium chloride tetrahydrate and thioacetamide in a mixed solvent of glycerol and water, the molar ratio of zinc chloride, indium chloride tetrahydrate and thioacetamide is 1:(2-5):(3-8), the pH value of the indium zinc sulfide precursor solution is adjusted to 1-4 by dilute hydrochloric acid, the volume ratio of glycerol to water is 1:(3-10), the temperature of the heating and stirring reaction is 50-80°C, and the reaction time is 1-5 h.

2. A method for preparing the covalently bonded tin sulfide / indium zinc sulfide composite material according to claim 1, characterized in that: Includes steps: (1) using a water-soluble tin source and a sulfur source as raw materials, conducting a hydrothermal reaction in an alkaline aqueous solution, and after the reaction is completed, washing and vacuum drying to prepare a one-dimensional tin sulfide nanobelt; the alkaline aqueous solution is a urea aqueous solution with a molar concentration of 0.2 to 0.5 mol / L; (2) adding the one-dimensional tin sulfide nanobelt obtained in step (1) to a precursor solution of indium zinc sulfide at a mass ratio of 5% to 20% of the one-dimensional tin sulfide nanobelt in the covalently bonded tin sulfide / indium zinc sulfide composite material, heating and stirring to react, and after the reaction is completed, washing and vacuum drying to prepare a covalently bonded tin sulfide / indium zinc sulfide composite material; the indium zinc sulfide precursor solution is obtained by dissolving zinc chloride, indium chloride tetrahydrate and thioacetamide in a mixed solvent of glycerol and water, the molar ratio of zinc chloride, indium chloride tetrahydrate and thioacetamide is 1:(2-5):(3-8), the pH value of the indium zinc sulfide precursor solution is adjusted to 1-4 by dilute hydrochloric acid, the volume ratio of glycerol to water is 1:(3-10), the temperature of the heating and stirring reaction is 50-80°C, and the reaction time is 1-5 h.

3. The method for preparing the covalently bonded tin sulfide / indium zinc sulfide composite material according to claim 2, characterized in that: The tin source is selected from one of stannous chloride, stannous sulfate and stannous acetate; the sulfur source is selected from one of thioacetamide, thiourea, sodium thiosulfate and ammonium sulfide.

4. The method for preparing the covalently bonded tin sulfide / indium zinc sulfide composite material according to claim 2, characterized in that: The molar ratio of the tin source to the sulfur source in step (1) is 1:(10-30).

5. The method for preparing the covalently bonded tin sulfide / indium zinc sulfide composite material according to claim 2, characterized in that: The temperature of the hydrothermal reaction in step (1) is 150-200°C, and the reaction time is 12-20 h.

6. The method for preparing the covalently bonded tin sulfide / indium zinc sulfide composite material according to claim 2, characterized in that: The one-dimensional tin sulfide nanobelt is added to the precursor solution of indium zinc sulfide at a mass ratio of 10% to 15% of the one-dimensional tin sulfide nanobelt in the covalently bonded tin sulfide / indium zinc sulfide composite material.

7. The method for preparing the covalently bonded tin sulfide / indium zinc sulfide composite material according to claim 2, characterized in that: In the steps (1) and (2), the product is washed 3 to 6 times with water and ethanol respectively, and vacuum drying is performed at 50 to 80° C. for 10 to 20 hours.

8. An application of a covalently bonded tin sulfide / indium zinc sulfide composite material, characterized in that: The covalently bonded tin(II) sulfide / indium zinc sulfide composite material according to claim 1 is used as a photocatalyst for photocatalytic water decomposition to produce hydrogen.

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