Preparation method and application of iron titanate / sulfur indium zinc composite material

Abstract

The invention belongs to the technical field of composite material photocatalysis, and provides a preparation method and application of an iron titanate / sulfur indium zinc composite material. According to the preparation method, in-situ growth is carried out through a two-step hydrothermal method, firstly, an iron source, a titanium source and the like are subjected to stirring, hydrothermal reaction and calcination to prepare ferric titanate, then the ferric titanate is mixed with a zinc source, an indium source, a sulfur source and the like, ultrasonic dispersion is carried out, hydrothermal reaction is carried out, and the composite material is obtained. The method has the advantages of abundant raw material sources, simple operation, no need of complex equipment and process, preparation cost reduction, and facilitation of large-scale industrial production. The prepared composite material has a good crystal structure, the recombination probability of photon-generated carriers can be reduced, and the photocatalytic activity is remarkably improved. The iron titanate / indium zinc sulfide composite material has good visible light degradation performance on various dye wastewater.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material photocatalysis, and in particular relates to a preparation method and application of an iron titanate / indium zinc sulfide composite material. Background Art

[0002] With the global energy crisis and environmental pollution becoming increasingly severe, the development of efficient and sustainable environmental governance and energy conversion technologies has become a research hotspot. Photocatalysis, as a highly promising green technology, has garnered widespread attention. Photocatalytic reactions utilize photogenerated charge carriers (electron-hole pairs) generated by photocatalysts under illumination to drive a series of chemical reactions, thereby achieving functions such as pollutant degradation, water splitting to produce hydrogen, and carbon dioxide reduction.

[0003] Among the many photocatalysts, composite materials offer unique advantages. By combining materials with different properties, key photocatalytic properties such as light absorption, photogenerated carrier separation efficiency, and stability can be effectively improved. For example, combining a semiconductor material with excellent light absorption with a material with a high specific surface area and excellent electron transport properties can broaden the photocatalyst's spectral response range, increase the migration rate of photogenerated carriers, and thus enhance photocatalytic activity.

[0004] Composite material photocatalysis has a wide range of applications in environmental governance and energy fields. In the environmental field, photocatalytic technology can be used to degrade harmful gases in the air, such as volatile organic compounds such as formaldehyde and benzene, as well as organic pollutants in water, such as dyes and pesticide residues. Through photocatalytic reactions, these pollutants can be completely decomposed into harmless carbon dioxide and water, achieving environmental purification. In the energy field, photocatalytic water decomposition to produce hydrogen provides a feasible way to obtain clean energy. Using solar energy to decompose water into hydrogen and oxygen, hydrogen, as an efficient and clean energy carrier, is expected to alleviate the current energy crisis. In addition, photocatalytic carbon dioxide reduction can convert carbon dioxide into valuable fuels or chemicals, realizing carbon recycling.

[0005] However, composite material photocatalysis still faces many challenges. First, the recombination rate of photogenerated carriers is relatively high, which seriously limits the further improvement of photocatalytic efficiency. Although the separation of photogenerated carriers can be promoted to a certain extent by combining different materials, in actual applications, photogenerated electrons and holes are still easy to recombine, resulting in low quantum efficiency of the photocatalytic reaction. Secondly, the stability of the photocatalyst cannot be ignored. During the long-term photocatalytic reaction, the photocatalyst may agglomerate, deactivate, and other phenomena, affecting its service life and actual application effect. In addition, the preparation methods of existing composite materials are often more complicated and costly, which is not conducive to large-scale industrial production.

[0006] To address these issues, developing efficient, stable, and easily prepared composite photocatalysts is of great practical significance. Zinc indium sulfide (ZnIn2S4), a ternary sulfide semiconductor, possesses a suitable bandgap and excellent visible light absorption, providing a large surface area and numerous active sites, making it a promising photocatalytic material. Iron titanate (FeTiO3), a perovskite-type oxide, exhibits excellent chemical stability and optical properties. Numerous studies have used ZnIn2S4 or FeTiO3 as base materials to construct composite materials with applications in environmental or energy fields. Truong et al. (10.1016 / j.catcom.2011.12.025) synthesized a FeTiO3 / TiO2 composite using a simple hydrothermal method. This composite exhibits remarkable photocatalytic activity for the reduction of CO2 to CH3OH under visible and UV-visible light irradiation, thanks to its unique band structure, efficient charge transfer between the two semiconductors, and the low bandgap of FeTiO3. Yuan et al. (10.1016 / j.cclet.2013.06.011) successfully synthesized a novel core-shell structured composite material TiO2@ZnIn2S4 by a simple and flexible hydrothermal method. The composite material is more effective than TiO2 and ZnIn2S4 in the photocatalytic degradation of methylene blue.

[0007] However, to date, there has been no report on the materials, preparation methods and applications of compounding the two materials, iron titanate / indium zinc sulfide composite materials.

[0008] In view of the above background and research status, the present invention is proposed. Summary of the Invention

[0009] The present invention provides a method for preparing an iron titanate / indium zinc sulfide composite material. This method utilizes a two-step hydrothermal method for in-situ growth, is simple to prepare, and utilizes abundant raw material resources. The composite material prepared by this method exhibits a well-defined crystalline structure, excellent carrier transport properties, and high photocatalytic activity.

[0010] Another object of the present invention is to provide an application of an iron titanate / indium zinc sulfide composite material in fields such as removing environmental pollutants.

[0011] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted: In a first aspect, the present invention provides a method for preparing an iron titanate / indium zinc sulfide composite material, comprising the following steps: (1) Preparation of iron titanate: Add an iron source to anhydrous ethanol, stir until completely dissolved, then add a titanium source dropwise, continue stirring and add ethylenediamine dropwise to form a sol, then perform a hydrothermal reaction, cool, wash with water, wash with alcohol, vacuum dry, and calcine under inert gas protection to obtain iron titanate; (2) Preparation of iron titanate / sulfur indium zinc composite material: The iron titanate, zinc source, indium source and sulfur source obtained in step (1) are added to anhydrous ethanol in a certain proportion, and hexadecyltrimethylammonium bromide is added. The solution is ultrasonically dispersed and then transferred to a hydrothermal autoclave for reaction. The obtained solid is centrifuged, washed and dried to obtain the iron titanate / sulfur indium zinc composite material.

[0012] In the present invention, the hydrothermal reaction and calcination operations are both carried out in equipment commonly used in the art, and this application does not make any special restrictions. For example, the hydrothermal reaction is carried out in a hydrothermal kettle, and the calcination is carried out in a tubular furnace.

[0013] In the method for preparing the iron titanate / indium zinc sulfide composite material of the present invention, the iron source in step (1) is one of ferric nitrate, ferric chloride and ferric sulfate.

[0014] In the method for preparing the iron titanate / indium zinc sulfide composite material of the present invention, the titanium source in step (1) is one of tetrabutyl titanate and / or tetraisopropyl titanate.

[0015] In the method for preparing the iron titanate / indium zinc sulfide composite material of the present invention, the zinc source in step (2) is one of hydrated zinc nitrate, zinc acetate dihydrate or zinc chloride.

[0016] In the preparation method of the iron titanate / indium zinc sulfide composite material described in the present invention, the indium source in step (2) is one of indium nitrate hydrate, indium trichloride hydrate or indium sulfate.

[0017] In the method for preparing the iron titanate / sulfur indium zinc composite material of the present invention, the sulfur source in step (2) is one of thioacetamide, sodium sulfide or thiourea.

[0018] In the method for preparing the iron titanate / sulfur indium zinc composite material of the present invention, the molar ratio of zinc atoms, indium atoms and sulfur atoms in step (2) is 1:2:6.

[0019] In some embodiments, in step (1), the hydrothermal reaction conditions are: temperature of 160-200° C., and reaction time of 8-24 hours.

[0020] In some embodiments, in step (1), the calcination conditions are: temperature of 650-700° C., time of 2-3 hours, and calcination atmosphere of nitrogen.

[0021] In some embodiments, in step (2), the hydrothermal reaction conditions are: temperature of 150-200° C., and reaction time of 8-24 hours.

[0022] In a second aspect, the present invention provides an application of the iron titanate / indium zinc sulfide composite material prepared by the above preparation method in the field of removing environmental pollutants.

[0023] The environmental pollutants include at least one of rhodamine B, methylene blue, and methyl orange dyes.

[0024] As a preferred embodiment, a method for preparing an iron titanate / sulfur indium zinc composite material comprises the following steps: (1) Preparation of iron titanate: Add an iron source to anhydrous ethanol, stir until completely dissolved, then add a titanium source dropwise, continue stirring and add ethylenediamine dropwise to form a sol, then perform a hydrothermal reaction, cool, wash with water, wash with alcohol, vacuum dry, and calcine under inert gas protection to obtain iron titanate; (2) Preparation of iron titanate / sulfur indium zinc composite material: The iron titanate, zinc source, indium source and sulfur source obtained in step (1) are added to anhydrous ethanol in a certain proportion, and hexadecyltrimethylammonium bromide is added. The solution is ultrasonically dispersed and then transferred to a hydrothermal autoclave for reaction. The obtained solid is centrifuged, washed and dried to obtain the iron titanate / sulfur indium zinc composite material.

[0025] Wherein, in step (1), the iron source is one of ferric nitrate, ferric chloride and ferric sulfate.

[0026] Wherein, in step (1), the titanium source is one of tetrabutyl titanate and / or tetraisopropyl titanate.

[0027] Wherein, in step (2), the zinc source is one of hydrated zinc nitrate, zinc acetate dihydrate or zinc chloride.

[0028] Wherein, in step (2), the indium source is one of indium nitrate hydrate, indium trichloride hydrate or indium sulfate.

[0029] Wherein, in step (2), the sulfur source is one of thioacetamide, sodium sulfide or thiourea.

[0030] Wherein, in step (2), the molar ratio of the zinc atoms, indium atoms and sulfur atoms is 1:2:6.

[0031] Wherein, in step (1), the hydrothermal reaction conditions are: temperature is 200°C, and reaction time is 12 hours.

[0032] Wherein, in step (1), the calcination conditions are: temperature of 700°C, time of 2 hours, and calcination atmosphere of nitrogen.

[0033] Wherein, in step (2), the hydrothermal reaction conditions are: temperature is 180°C, and reaction time is 24 hours.

[0034] The beneficial effects of the technical solution provided by the present invention are as follows: in terms of the preparation method, a two-step hydrothermal method is adopted for in-situ growth, which is easy to operate, does not require complex equipment and processes, and has a wide range of raw materials, which reduces the preparation cost and lays the foundation for large-scale industrial production. From the perspective of composite material performance, the obtained iron titanate / sulfur indium zinc composite material has a good crystal structure, which helps to efficiently transmit photogenerated carriers within the material, reduces the probability of carrier recombination, and significantly improves photocatalytic activity, and can play a better role in applications such as environmental pollutant removal. In the field of environmental governance, the composite material can effectively remove dye pollutants such as rhodamine B, methylene blue, and methyl orange, and completely decompose them into harmless carbon dioxide and water, helping to solve water pollution problems and achieve environmental purification. In summary, the technical solution of the present invention shows outstanding advantages in terms of preparation convenience, material performance improvement, and environmental governance applications, which is of great significance to promoting the development and practical application of composite material photocatalytic technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the XRD pattern of the sample obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples were prepared according to existing methods or directly purchased from the market.

[0038] The reagents and raw materials used in the present invention are shown in Table 1 below: Table 1 Reagents and raw materials used in the present invention Reagent name Molecular formula Specification Manufacturer (Origin) Ferric chloride <![CDATA[FeCl3·6H2O]]> analytically pure Shanghai MacLean Biochemical Technology Co., Ltd. Ferric nitrate <![CDATA[Fe(NO3)3·9H2O]]> analytically pure Shanghai MacLean Biochemical Technology Co., Ltd. Ethylenediamine <![CDATA[C2H8N2·H2O]]> analytically pure Aladdin Chemical Reagent Co., Ltd. Tetrabutyl titanate <![CDATA[C 16 H 36 O4Ti]]> analytically pure Sinopharm Chemical Reagent Co., Ltd. Cetyltrimethylammonium bromide CTAB analytically pure Shanghai MacLean Biochemical Technology Co., Ltd. Zinc acetate dihydrate <![CDATA[Zn(CH3COO)2·2H2O]]> analytically pure Sinopharm Chemical Reagent Co., Ltd. Indium nitrate hydrate <![CDATA[In(NO)3·xH2O]]> analytically pure Shanghai MacLean Biochemical Technology Co., Ltd. Thioacetamide <![CDATA[C2H5NS]]> analytically pure Sinopharm Chemical Reagent Co., Ltd. Deionized water <![CDATA[H2O]]> <![CDATA[S<5 μs·cm -1 ]]> Hangzhou Wahaha Group Co., Ltd. Example 1

[0039] Accurately weigh 3.56 g of ferric nitrate and dissolve it in 50 ml of anhydrous ethanol to form a reddish-brown solution. While stirring, accurately pipette 3 ml of tetrabutyl titanate (approximately 3 g) and add it dropwise to the solution. Continue stirring for 30 minutes, then transfer the solution to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave. Add ethylenediamine dropwise until the solution forms a sol. Add anhydrous ethanol to approximately 70% concentration, then react at 200°C for 12 hours. The resulting precipitate is washed with water and then with alcohol, then vacuum-dried at 60°C. The product is calcined at 700°C in a tube furnace under nitrogen for 2 hours to yield ferric titanate. Accurately weigh 0.5 g of the above-mentioned iron titanate and add it to 50 ml of anhydrous ethanol. Weigh 2 mmol of zinc acetate dihydrate, 4 mmol of indium nitrate hydrate and 12 mmol of thioacetamide respectively in a 100 ml beaker, add 50 ml of anhydrous ethanol, stir to dissolve, then add 0.1 g of hexadecyltrimethylammonium bromide. Continue ultrasonication and stirring, then transfer to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave, add anhydrous ethanol to 75% of the total capacity, and after hydrothermal reaction at 180°C for 24 hours, the obtained solid is centrifuged, washed with water and alcohol for 3 times each, and vacuum dried at 60°C for 24 hours to obtain an iron titanate / sulfur indium zinc composite material.

[0040] 100 mg of the prepared iron titanate / indium zinc sulfide composite material was placed in a beaker containing 100 ml of a 10 mg / L rhodamine B solution, subjected to ultrasonic treatment for 5 minutes, dark adsorbed for 30 minutes, and then illuminated with a 300-watt xenon lamp at a distance of 20 cm from the liquid surface for 60 minutes under stirring. The degraded solution was centrifuged and its absorbance at 554 nm was measured by a UV-visible spectrophotometer. The degradation rate of rhodamine B was calculated to be 95.6%.

[0041] The present invention uses a D8 Advance X-ray diffractometer from Bruker Spectroscopy Instruments of Germany to perform XRD characterization on the iron titanate / sulfur indium zinc composite material prepared in Example 1 of the present invention, and the results are as follows: Figure 1 The test conditions are: Cu target Kα line, λ = 0.15406 nm, 2θ range of 10° to 70°, and scanning speed of 10° / min. Figure 1 The product of Example 1 is an iron titanate / indium zinc sulfide composite material. The diffraction peaks at 27.4° and 47.5° in the figure correspond to the (102) and (110) crystal planes of indium zinc sulfide (JCPDS 65-2023), respectively. The remaining characteristic peaks are attributed to the (002), (200), (201), (110), (111), (112), (203), (004), (310), (400), and (113) crystal planes of iron titanate (JCPDS 73-1631) of the Ccmm space group. All the peaks are sharp, indicating that the prepared samples have good crystal form and high purity. Example 2

[0042] Accurately weigh 3.56 g of ferric nitrate and dissolve it in 50 ml of anhydrous ethanol to form a reddish-brown solution. While stirring, accurately pipette 3 ml of tetrabutyl titanate (approximately 3 g) and add it dropwise to the solution. Continue stirring for 30 minutes, then transfer the solution to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave. Add ethylenediamine dropwise until the solution forms a sol. Add anhydrous ethanol to approximately 70% concentration, then react at 200°C for 12 hours. The resulting precipitate is washed with water and then with alcohol, then vacuum-dried at 60°C. The product is calcined at 700°C in a tube furnace under nitrogen for 2 hours to yield ferric titanate. Accurately weigh 0.5 g of the above-mentioned iron titanate and add it to 50 ml of anhydrous ethanol. Weigh 2 mmol of zinc acetate dihydrate, 4 mmol of indium nitrate hydrate and 12 mmol of thioacetamide respectively in a 100 ml beaker, add 50 ml of anhydrous ethanol, stir to dissolve, then add 0.1 g of hexadecyltrimethylammonium bromide. Continue ultrasonication and stirring, then transfer to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave, add anhydrous ethanol to 75% of the total capacity, and after hydrothermal reaction at 180°C for 24 hours, the obtained solid is centrifuged, washed with water and alcohol for 3 times each, and vacuum dried at 60°C for 24 hours to obtain an iron titanate / sulfur indium zinc composite material.

[0043] 100 mg of the prepared iron titanate / indium zinc sulfide composite material was placed in a beaker containing 100 ml of a 10 mg / L methylene blue solution, ultrasonically treated for 5 minutes, dark adsorbed for 30 minutes, and then illuminated for 60 minutes with a 300-watt xenon lamp at a distance of 20 cm from the liquid surface under stirring. The degraded solution was centrifuged and its absorbance at 664 nm was measured by a UV-visible spectrophotometer. The degradation rate of methylene blue was calculated to be 92.1%. Example 3

[0044] Accurately weigh 3.56 g of ferric nitrate and dissolve it in 50 ml of anhydrous ethanol to form a reddish-brown solution. While stirring, accurately pipette 3 ml of tetrabutyl titanate (approximately 3 g) and add it dropwise to the solution. Continue stirring for 30 minutes, then transfer the solution to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave. Add ethylenediamine dropwise until the solution forms a sol. Add anhydrous ethanol to approximately 70% concentration, then react at 200°C for 12 hours. The resulting precipitate is washed with water and then with alcohol, then vacuum-dried at 60°C. The product is calcined at 700°C in a tube furnace under nitrogen for 2 hours to yield ferric titanate. Accurately weigh 0.5 g of the above-mentioned iron titanate and add it to 50 ml of anhydrous ethanol. Weigh 2 mmol of zinc acetate dihydrate, 4 mmol of indium nitrate hydrate and 12 mmol of thioacetamide respectively in a 100 ml beaker, add 50 ml of anhydrous ethanol, stir to dissolve, then add 0.1 g of hexadecyltrimethylammonium bromide. Continue ultrasonication and stirring, then transfer to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave, add anhydrous ethanol to 75% of the total capacity, and after hydrothermal reaction at 180°C for 24 hours, the obtained solid is centrifuged, washed with water and alcohol for 3 times each, and vacuum dried at 60°C for 24 hours to obtain an iron titanate / sulfur indium zinc composite material.

[0045] 100 mg of the prepared iron titanate / indium zinc sulfide composite material was placed in a beaker containing 100 ml of a 10 mg / L methyl orange solution, ultrasonically treated for 5 minutes, dark adsorbed for 30 minutes, and then illuminated for 60 minutes with a 300-watt xenon lamp at a distance of 20 cm from the liquid surface under stirring. The degraded solution was centrifuged and its absorbance at 460 nm was measured by a UV-visible spectrophotometer. The degradation rate of methyl orange was calculated to be 85.7%. Example 4

[0046] Accurately weigh 3.56 g of ferric nitrate and dissolve it in 50 ml of anhydrous ethanol to form a reddish-brown solution. While stirring, accurately pipette 3 ml of tetrabutyl titanate (approximately 3 g) and add it dropwise to the solution. Stirring is continued for 30 minutes. The solution is then transferred to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave. Ethylenediamine is added dropwise until the solution forms a sol. Anhydrous ethanol is added to approximately 70% of the concentration, and the mixture is reacted at 160°C for 8 hours. The resulting precipitate is washed with water and then with alcohol, then vacuum-dried at 60°C. The product is calcined at 650°C in a tube furnace under nitrogen for 2 hours to yield ferric titanate. Accurately weigh 0.5 g of the above-mentioned iron titanate and add it to 50 ml of anhydrous ethanol. Weigh 2 mmol of zinc acetate dihydrate, 4 mmol of indium nitrate hydrate and 12 mmol of thioacetamide respectively in a 100 ml beaker, add 50 ml of anhydrous ethanol, stir to dissolve, then add 0.1 g of hexadecyltrimethylammonium bromide. Continue ultrasonication and stirring, then transfer to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave, add anhydrous ethanol to 75% of the total capacity, and carry out hydrothermal reaction at 150 ° C for 8 hours. The obtained solid is centrifuged, washed with water and alcohol for 3 times each, and vacuum dried at 60 ° C for 24 hours to obtain an iron titanate / sulfur indium zinc composite material.

[0047] 100 mg of the prepared iron titanate / indium zinc sulfide composite material was placed in a beaker containing 100 ml of a 10 mg / L rhodamine B solution, subjected to ultrasonic treatment for 5 minutes, dark adsorbed for 30 minutes, and then illuminated for 60 minutes with a 300-watt xenon lamp at a distance of 20 cm from the liquid surface under stirring. The degraded solution was centrifuged and its absorbance at 554 nm was measured by a UV-visible spectrophotometer. The degradation rate of rhodamine B was calculated to be 90.8%. Example 5

[0048] Accurately weigh 3.56 g of ferric nitrate and dissolve it in 50 ml of anhydrous ethanol to form a reddish-brown solution. While stirring, accurately pipette 3 ml of tetrabutyl titanate (approximately 3 g) and add it dropwise to the solution. Continue stirring for 30 minutes, then transfer the solution to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave. Add ethylenediamine dropwise until the solution forms a sol. Add anhydrous ethanol to approximately 70% concentration, then react at 200°C for 24 hours. The resulting precipitate is washed with water and alcohol, then vacuum-dried at 60°C. The product is calcined at 700°C in a tube furnace under nitrogen for 2 hours to yield ferric titanate. Accurately weigh 0.5 g of the above-mentioned iron titanate and add it to 50 ml of anhydrous ethanol. Weigh 2 mmol of zinc acetate dihydrate, 4 mmol of indium nitrate hydrate and 12 mmol of thioacetamide respectively in a 100 ml beaker, add 50 ml of anhydrous ethanol, stir to dissolve, then add 0.1 g of hexadecyltrimethylammonium bromide. Continue ultrasonication and stirring, then transfer to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave, add anhydrous ethanol to 75% of the total capacity, and hydrothermally react at 200°C for 24 hours. The obtained solid is centrifuged, washed with water and alcohol 3 times each, and vacuum dried at 60°C for 24 hours to obtain an iron titanate / sulfur indium zinc composite material.

[0049] 100 mg of the prepared iron titanate / indium zinc sulfide composite material was placed in a beaker containing 100 ml of a 10 mg / L rhodamine B solution, subjected to ultrasonic treatment for 5 minutes, dark adsorbed for 30 minutes, and then illuminated with a 300-watt xenon lamp at a distance of 20 cm from the liquid surface for 60 minutes under stirring. The degraded solution was centrifuged and its absorbance at 554 nm was measured by a UV-visible spectrophotometer. The degradation rate of rhodamine B was calculated to be 97.3%. Comparative Example 1

[0050] Accurately weigh 3.56 g of ferric nitrate and dissolve it in 50 ml of anhydrous ethanol to form a reddish-brown solution. While stirring, accurately pipette 3 ml of tetrabutyl titanate (approximately 3 g) and add it dropwise to the solution. Stirring continues for 30 minutes. The solution is then transferred to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave. Ethylenediamine is added dropwise until the solution forms a sol. Anhydrous ethanol is added to approximately 70% of the solution concentration, and the reaction is continued at 200°C for 12 hours. The resulting precipitate is washed with water and then with alcohol, then vacuum-dried at 60°C. The product is calcined in a tube furnace at 700°C for 2 hours under nitrogen to obtain the iron titanate monomer.

[0051] 100 mg of the prepared iron titanate monomer material was placed in a beaker containing 100 ml of a 10 mg / L rhodamine B solution, ultrasonically treated for 5 minutes, darkly adsorbed for 30 minutes, and then illuminated for 60 minutes with a 300-watt xenon lamp at a distance of 20 cm from the liquid surface under stirring. The degraded solution was centrifuged and its absorbance at 554 nm was measured by a UV-visible spectrophotometer. The degradation rate of rhodamine B was calculated to be 20.2%. Comparative Example 2

[0052] 2 mmol of zinc acetate dihydrate, 4 mmol of indium nitrate hydrate and 12 mmol of thioacetamide were weighed separately in a 100 ml beaker, 50 ml of anhydrous ethanol was added, and after stirring to dissolve, 0.1 g of hexadecyltrimethylammonium bromide was added. After continued ultrasonication and stirring, the mixture was transferred to a 100 ml polytetrafluoroethylene-lined hydrothermal autoclave, and anhydrous ethanol was added to 75% of the total capacity. After hydrothermal reaction at 180°C for 24 hours, the obtained solid was centrifuged, washed with water and alcohol for 3 times each, and vacuum dried at 60°C for 24 hours to obtain sulfur indium zinc monomer material.

[0053] 100 mg of the prepared indium zinc sulfide monomer material was placed in a beaker containing 100 ml of a 10 mg / L rhodamine B solution, ultrasonically treated for 2 minutes, dark adsorbed for 30 minutes, and then illuminated with a 300-watt xenon lamp at a distance of 20 cm from the liquid surface for 60 minutes under stirring. The degraded solution was centrifuged and its absorbance at 554 nm was measured by a UV-visible spectrophotometer. The degradation rate of rhodamine B was calculated to be 46.8%.

[0054] It can be seen from Comparative Examples 1 and 2 that the degradation effect of the prepared iron titanate monomer material and indium zinc sulfide monomer material on rhodamine B is significantly lower than that of the iron titanate / indium zinc sulfide composite material under the same conditions. This is mainly because neither the iron titanate monomer material nor the indium zinc sulfide monomer material forms a spatial electric field for efficient separation of photogenerated carriers, and photogenerated electrons and holes are easily revived.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an iron titanate / indium zinc sulfide composite material, characterized in that: The steps include: (1) Preparation of iron titanate: Add an iron source to anhydrous ethanol, stir until completely dissolved, then add a titanium source dropwise, continue stirring and add ethylenediamine dropwise to form a sol, then perform a hydrothermal reaction, cool, wash with water, wash with alcohol, vacuum dry, and calcine under inert gas protection to obtain iron titanate; (2) Preparation of iron titanate / sulfur indium zinc composite material: adding the iron titanate, zinc source, indium source and sulfur source obtained in step (1) to anhydrous ethanol in a certain proportion, adding hexadecyltrimethylammonium bromide, ultrasonically dispersing to form a solution, and then transferring the solution to a hydrothermal autoclave for reaction. The obtained solid is centrifuged, washed and dried to obtain the iron titanate / sulfur indium zinc composite material; Wherein, in step (1), the hydrothermal reaction conditions are: temperature of 160-200°C, reaction time of 8-24 hours; in step (1), the calcination conditions are: temperature of 650-700°C, time of 2-3 hours, and calcination atmosphere of nitrogen; in step (2), the hydrothermal reaction conditions are: temperature of 150-200°C, reaction time of 8-24 hours.

2. The preparation method according to claim 1, characterized in that The iron source in step (1) is one of ferric nitrate, ferric chloride and ferric sulfate.

3. The preparation method according to claim 1, characterized in that The titanium source in step (1) is one of tetrabutyl titanate and / or tetraisopropyl titanate.

4. The preparation method according to claim 1, characterized in that The zinc source in step (2) is one of hydrated zinc nitrate, zinc acetate dihydrate or zinc chloride.

5. The preparation method according to claim 1, characterized in that The indium source in step (2) is one of indium nitrate hydrate, indium trichloride hydrate or indium sulfate.

6. The preparation method according to claim 1, characterized in that The sulfur source in step (2) is one of thioacetamide, sodium sulfide or thiourea.

7. The preparation method according to claim 1, characterized in that The molar ratio of zinc atoms, indium atoms and sulfur atoms in step (2) is 1:2:

6.

8. Use of the iron titanate / indium zinc sulfide composite material obtained by the preparation method according to any one of claims 1 to 7 in removing environmental pollutants.

9. The use according to claim 8, characterized in that The environmental pollutants include at least one of rhodamine B, methylene blue, and methyl orange dyes.

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