Preparation method and application of Ge-doped ZnSn(OH)6 photocatalyst

Abstract

The application relates to the field of photocatalytic materials, and discloses a preparation method and application of a Ge-doped ZnSn(OH)6 photocatalyst. The Ge-doped ZnSn(OH)6 photocatalyst is prepared by using SnCl4.5H2O, Zn(Ac)2.2H2O, alkali metal hydroxide, methyl cellulose and GeO2 as raw materials through a hydrothermal synthesis method. The crystalline powder can be obtained without high-temperature sintering, the catalyst can generate a large amount of electrons and hydroxyl radicals, has excellent degradation effect on volatile organic compounds such as methylbenzene, can realize 100% removal effect on 50ppm concentration methylbenzene within 10 minutes, has excellent deep mineralization capacity, and has great potential for pollution prevention and treatment of atmospheric environment.

Description

Technical Field

[0001] This application relates to the field of photocatalytic materials, specifically to a method for preparing a Ge-doped ZnSn(OH)6 photocatalyst and its application. Background Technology

[0002] Zinc hydroxystannate (ZnSn(OH)6) is a mixed metal oxide and a transition metal hydroxide with a large specific surface area and a unique electronic structure. It has a wide band gap, a crystal structure that facilitates electron transport, and high chemical stability during photocatalytic reactions, making it resistant to corrosion and decomposition. These advantages make zinc hydroxystannate a promising candidate for applications in environmental pollution control, photocatalytic water splitting for hydrogen production, and air purification.

[0003] Current methods for preparing ZnSn(OH)6 include solvothermal, hydrothermal, and coprecipitation methods. These methods optimize photocatalytic performance by controlling the crystal form, particle size, and morphology of the material. Among current research advancements, the most extensively studied methods include adjusting the band gap of ZnSn(OH)6 through doping, constructing heterostructures to improve the separation efficiency of photogenerated electron-hole pairs, and increasing specific surface area through nanostructure modulation. However, the photocatalysts prepared using these modification strategies cannot yet achieve rapid and effective complete removal of toluene.

[0004] Therefore, there is an urgent need to develop a photocatalyst preparation method with superior product performance. Summary of the Invention

[0005] Technical issues

[0006] A method for preparing a Ge-doped photocatalyst based on ZnSn(OH)6 is provided. The prepared ZnSn(OH)6 can more effectively excite electron-hole pair separation and accelerate electron transfer under light irradiation. At the same time, it can generate more hydroxyl radicals with H2O, thereby achieving complete removal of toluene in a short time.

[0007] Technical solution

[0008] The first aspect of this application provides a method for preparing a Ge-doped ZnSn(OH)6 photocatalyst, comprising: using SnCl4·5H2O, Zn(Ac)2·2H2O, NaOH, methylcellulose and GeO2 as raw materials, and preparing the Ge-doped ZnSn(OH)6 photocatalyst by hydrothermal synthesis.

[0009] In some embodiments, the specific preparation steps of the Ge-doped ZnSn(OH)6 photocatalyst are as follows:

[0010] a. Add SnCl4·5H2O, Zn(Ac)2·2H2O, alkali metal hydroxide, methylcellulose and GeO2 to distilled water and stir to obtain a mixture;

[0011] b. The mixture is placed in a sealed pressure vessel and subjected to a hydrothermal reaction. After the reaction is completed and cooled to room temperature, it is washed, dried and ground to obtain Ge-doped ZnSn(OH)6 photocatalyst crystalline powder.

[0012] In some embodiments, the alkali metal hydroxide is NaOH, KOH, or LiOH.

[0013] Furthermore, the alkali metal hydroxide is NaOH.

[0014] In some embodiments, the molar ratio of SnCl4·5H2O, Zn(Ac)2·2H2O, alkali metal hydroxide, and GeO2 is 1:1 to 1.2:7 to 8.4:0.07 to 4.8.

[0015] Furthermore, the molar ratio of SnCl4·5H2O, Zn(Ac)2·2H2O, NaOH, and GeO2 is 1:1~1.2:7~8.4:0.12~4.8.

[0016] Furthermore, the molar ratio of SnCl4·5H2O, Zn(Ac)2·2H2O, NaOH, and GeO2 is 1:1:7:0.6.

[0017] In some embodiments, the stirring conditions are specifically: 500–800 r / min; 10–20 min.

[0018] In some embodiments, the hydrothermal reaction temperature is raised from room temperature to 160°C to 165°C, and then kept at that temperature for 390 min to 400 min.

[0019] Furthermore, the hydrothermal reaction temperature was raised from room temperature to 160°C and then held for 390 minutes.

[0020] In some embodiments, the washing process includes: cooling to room temperature and then washing twice each with distilled water and anhydrous ethanol.

[0021] In some embodiments, the drying conditions are specifically: drying at 55°C to 65°C for 6 to 8 hours.

[0022] The second aspect of this application provides the application of the Ge-doped ZnSn(OH)6 photocatalyst prepared by the method described in this application in the removal of toluene contaminants or in the preparation of photocatalytic products that remove toluene contaminants.

[0023] Technical effect

[0024] Current research focuses on ZnSn(OH)6 doped with elements such as C and S, but there is no research on the application of Ge element in modifying ZnSn(OH)6 photocatalysts. This application presents a Ge-doped ZnSn(OH)6 photocatalyst prepared via hydrothermal synthesis. This photocatalyst can be obtained as a crystalline powder without high-temperature sintering and can generate a large number of electrons and hydroxyl radicals in a short time under light irradiation, achieving highly efficient removal of the volatile organic compound toluene, thus providing a better measure for environmental pollution control. Attached Figure Description

[0025] Figure 1 The X-ray diffraction patterns of cubic Ge-doped ZnSn(OH)6 prepared in Examples 1-12 are shown. In the figures, ZHS-1, ZHS-2, ZHS-3, ZHS-4, ZHS-5, ZHS-6, ZHS-7, ZHS-8, ZHS-9, ZHS-10, ZHS-11, and ZHS-12 represent the photocatalysts prepared in Examples 1, Comparative Example 1, and Examples 3-12, respectively (the same applies below).

[0026] Figure 2 The image shown is a scanning electron microscope (SEM) image of the Ge-doped ZnSn(OH)6 photocatalyst of this application.

[0027] Figure 3 The image shows a comparison of the XPS full spectrum of Example 1 and Comparative Example 1;

[0028] Figure 4 The figure shows a line graph of the photocatalytic activity of the products obtained in Examples 1-12 for removing toluene; in the figure, the vertical axis value represents the percentage of toluene activity, and the removal rate is the difference before and after photocatalysis.

[0029] Figure 5 The figure shows a line graph of the photocatalytic removal of toluene mineralization rate of the products obtained in Examples 1-12; in the figure, the vertical axis value represents the percentage of toluene mineralization rate, and the mineralization rate is the difference before and after photocatalysis.

[0030] Figure 6 The figure shows a line graph of the photocatalytic activity of the product obtained in Comparative Example 1 in removing toluene under different concentrations of humid air; in the figure, the vertical axis value represents the percentage of toluene activity, and the removal rate is the difference before and after photocatalysis (the same below).

[0031] Figure 7 The figure shows a line graph of the photocatalytic activity of the product obtained in Example 1 for the removal of toluene under different concentrations of humid air.

[0032] Figure 8The figure shows a comparison of the photocatalytic activity of toluene obtained from Example 1, Comparative Examples 2 and 3; in the figure, ZHS-1, Ge-Ca, and Ge-Ti represent the photocatalysts prepared in Example 1, Comparative Examples 2 and 3 respectively (the same below);

[0033] Figure 9 The figure shown is a line graph illustrating the stability test of photocatalytic removal of toluene contaminants in Example 1 within 335 min.

[0034] Figure 10 The diagram shows a comparison of the electrical impedance of the products obtained in Example 1 and Comparative Example 1 with that of single GeO2.

[0035] Figure 11 The images show the products obtained in Example 1 and Comparative Example 1, as well as the single product GeO2 capturing e. - Electron spin resonance spectrum;

[0036] Figure 12 The images show the electron spin resonance spectra of the products obtained in Example 1, Comparative Example 1, and the single product GeO2 capturing ·OH. Detailed Implementation

[0037] To facilitate the explanation of the technical solution of this application, the following is a general explanation and definition of the terms and expressions used in this application.

[0038] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0039] In the comparative experiments provided in this application, unless otherwise specified, all experimental conditions and materials are kept consistent to ensure comparability.

[0040] Unless otherwise specified, all reagents and instruments used in the embodiments of this invention can be purchased from the market.

[0041] This application describes the preparation of a Ge-doped ZnSn(OH)6 photocatalyst via hydrothermal synthesis using SnCl4·5H2O, Zn(Ac)2·2H2O, NaOH, methylcellulose, and GeO2 as raw materials. Based on a "crystallization-dissolution-recrystallization" mechanism, the reaction occurs during hydrothermal synthesis: Zn 2+ +Sn 4+ +6OH- +Ge 4+ →ZnSn(OH)6 (containing Ge ions). The hydrothermal synthesis strategy has the advantages of high crystallinity of the synthesized product, controllable crystal particle size, and good uniform dispersion of the obtained powder. Ge ions are effectively incorporated into the ZnSn(OH)6 lattice at 160℃. The Ge-doped ZnSn(OH)6 photocatalyst prepared by this method has a single phase, photogenerated carriers are not easily recombine, and have a fast migration rate. It can generate a large number of electrons and hydroxyl radicals in a short time, thereby achieving efficient removal of volatile organic compounds from toluene and maintaining stable catalytic performance over a long period.

[0042] In the hydrothermal reaction in the reactor, water is used as the medium, and stirring helps to promote the rapid dissolution of SnCl4, Zn(Ac)2, and NaOH in the water, forming a solution containing a large amount of Sn. 4+ Zn 2+ OH -+ In a mixed solution of ions, GeO2 can also be separated into GeO2 during a hydrothermal reaction at 160℃. 4+ Ions facilitate the subsequent Zn extraction process. 2+ +Sn 4+ +6OH - +Ge 4+ →ZnSn(OH)6 (containing Ge ions) is synthesized. The subsequent addition of methylcellulose surfactant forms ordered aggregates (such as micelles) in solution, which act as a reaction medium, effectively controlling the size and morphology of Ge-doped ZnSn(OH)6 nanoparticles. This yields a photocatalyst with excellent mineralization properties for toluene.

[0043] The specific hydrothermal reaction temperature conditions in this application are as follows: synthesis is carried out by raising the temperature from room temperature to 160°C, holding at 160°C for 390 min, and then cooling to room temperature. Controlling the hydrothermal synthesis temperature within a suitable temperature and time range helps ensure the high crystallinity of the ZnSn(OH)6 catalyst, the complete reaction of the precursors, avoids the introduction of impurities, ensures high purity, and effectively controls the morphology and particle size of the material. If the synthesis temperature is too low, Ge ions cannot be incorporated into ZnSn(OH)6, resulting in unreacted precursors and intermediates in the product, insufficient energy to promote crystal growth, and the potential generation of byproducts that affect the purity of the material. If the synthesis temperature is too high, it not only increases energy consumption but may also cause material degradation. Furthermore, under high-temperature conditions, the crystals may grow too large, leading to increased particle size, which is detrimental to material applications. Rapid growth under high-temperature conditions also increases internal stress in the crystals, reducing mechanical strength. If the holding time is too short, unstable phases will be generated and there will be too many defects inside the crystal; if the holding time is too long, energy consumption costs will increase, and it will also lead to the transformation of ZnSn(OH)6 to Zn2SnO4.

[0044] In some embodiments of this application, 0-1g of GeO2 is added; in other embodiments, the mass of GeO2 added is 0g, 0.025g, 0.05g, 0.75g, 0.1g, 0.125g, 0.25g, 0.375g, 0.5g, 0.75g, or 1g. Controlling the mass of added GeO2 within a suitable range can save time and reagents, maximizing economic benefits, while ensuring that the obtained Ge-doped ZnSn(OH)6 photocatalyst exhibits excellent photocatalytic performance towards toluene.

[0045] In some embodiments of this application, post-treatment of the prepared Ge-doped ZnSn(OH)6 photocatalyst is further included: after cooling, the prepared Ge-doped ZnSn(OH)6 photocatalyst is washed twice each with distilled water and anhydrous ethanol, and then dried at 60°C for 6–8 hours. Grinding the Ge-doped ZnSn(OH)6 photocatalyst into finer particles improves the strength and toughness of the material, increases its specific surface area, and simultaneously improves the surface finish and precision of the material.

[0046] In other embodiments of this application, multiple characterization experiments have demonstrated that, compared to conventional unmodified ZnSn(OH)6, the Ge-doped ZnSn(OH)6 catalyst prepared in this application exhibits significantly higher photocatalytic (UV light) activity against toluene than unmodified ZnSn(OH)6. Therefore, this application also provides the application of the Ge-doped ZnSn(OH)6 photocatalyst prepared by the aforementioned method in the removal of toluene contaminants, or in the preparation of photocatalytic products for removing toluene contaminants.

[0047] The following provides a further explanation of the preparation method and application of a Ge-doped ZnSn(OH)6 photocatalyst provided in this application.

[0048] Example 1: Preparation of highly active Ge-doped ZnSn(OH)6 photocatalyst

[0049] 4 mL of Zn(Ac)₂·2H₂O (0.5 M), 4 mL of SnCl₄·5H₂O (0.5 M), 4.6 mL of NaOH (3 M), and 0.125 g of GeO₂ were sequentially added to a beaker containing 60 mL of distilled water. The mixture was stirred at 500-800 rpm for 5-10 minutes to obtain a white solution. Then, 10 mL of methylcellulose (2.8 g·L⁻¹) was added. -1 After stirring for 5–10 minutes, add 40 mL of distilled water and transfer the mixture to a Teflon-lined stainless steel autoclave. At this point, the concentrations of Zn(Ac)₂·2H₂O, SnCl₄·5H₂O, NaOH, and methylcellulose in the autoclave are 0.016 M, 0.112 M, and 0.23 g / L, respectively. Seal the autoclave and place it in an oven for heating synthesis. The synthesis temperature is raised from room temperature to 160–165 °C (160 °C in this example) and held for 390–400 minutes (390 minutes in this example), then cooled to room temperature. After the autoclave cools to room temperature, wash the resulting precipitate twice with distilled water and twice with anhydrous ethanol. Then, dry the precipitate in an oven at 55–65 °C (60 °C in this example) for 6–8 hours to obtain the final product. Finally, the product was ground to obtain Ge-doped ZnSn(OH)6.

[0050] Example 2: Preparation of a comparative Ge-doped photocatalyst

[0051] Comparative Example 1

[0052] The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0g of GeO2.

[0053] Comparative Example 2

[0054] The difference from Example 1 is that ZnSn(OH)6 was replaced with the same mass of CaCO3 (CAS No.: 471-34-1, reagent grade, 99%) to prepare Ge-doped CaCO3.

[0055] Comparative Example 3

[0056] The difference from Example 1 is that ZnSn(OH)6 was replaced with the same mass of TiO2 (CAS No.: 13463-67-7, reagent grade, 99%) to prepare Ge-doped TiO2.

[0057] Example 3: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.015g of GeO2.

[0058] Example 4: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.025g of GeO2.

[0059] Example 5: The difference from Example 1 is that 0.25g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.05g of GeO2.

[0060] Example 6: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.075g of GeO2.

[0061] Example 7: The difference from Example 1 is that 0.125g of GeO2 added to the beaker containing 60mL of distilled water was replaced with 0.1g of GeO. 2。

[0062] Example 8: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.25g of GeO2.

[0063] Example 9: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.375g of GeO2.

[0064] Example 10: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.5g of GeO2.

[0065] Example 11: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 0.75g of GeO2.

[0066] Example 12: The difference from Example 1 is that 0.125g of GeO2 added to a beaker containing 60mL of distilled water was replaced with 1g of GeO2.

[0067] Example 13: The difference from Example 1 is that 4 mL of Zn(Ac)2·2H2O (0.5M) was replaced with 4.8 mL of Zn(Ac)2·2H2O (0.5M).

[0068] Example 14: The difference from Example 1 is that 4.6 mL of NaOH (3M) was replaced with 5.5 mL of NaOH (3M).

[0069] Example 15: The difference from Example 1 is that KOH is used instead of NaOH.

[0070] Example 16: Performance Characterization Experiments of Different Photocatalysts

[0071] Multiple characterization experiments were conducted using the photocatalysts of Examples 1 to 12. In some experimental results, Examples 1 and 3 to 12 can be abbreviated as ZHS-1, ZHS-3, ZHS-4, ZHS-5, ZHS-6, ZHS-7, ZHS-8, ZHS-9, ZHS-10, ZHS-11, and ZHS-12, respectively. Comparative Examples 1 to 3 of Example 2 can be abbreviated as ZHS-2, Ge-Ca, and Ge-Ti in some experimental results.

[0072] Experiment 1: XRD characterization

[0073] To verify the types of ZHS-1 to ZHS-12, this application used a German Bruker D8 Advance X-ray diffractometer (CuKα, λ = 0.154 nm, operating voltage and current 40 kV and 40 mA, respectively) to perform XRD tests on each product. Figure 1 As shown, XRD results indicate that the diffraction peaks at 19.34°, 22.46°, 32.13°, 39.72°, 46.33°, 52.26°, and 57.75° of the products obtained in Examples 1-8 correspond to the ZnSn(OH)6 (JCPDS 74-1825) planes (111), (200), (220), (222), (400), (420), and (422), respectively, and no other impurity peaks were found. However, with the increase of doping amount, the peak intensity gradually decreased, and almost no peaks were visible in ZHS-9 to ZHS-12. This indicates that the addition of excessive GeO2 reduces the crystallinity of the material. In addition, all diffraction peaks were slightly shifted to higher diffraction angles. This may be due to the substitution of Sn atoms by Ge atoms, and the radius of Ge atoms is smaller than that of Sn atoms. The introduction of GeO2 changes the coordination environment of the crystal, causing lattice deformation. According to Bragg's formula 2dsinθ=nλ, the interplanar spacing shows a decreasing trend, which further indicates that the successful introduction of Ge ions causes changes in the crystal structure.

[0074] Experiment 2: Electron Microscopy Characterization

[0075] The morphology of the sample from Example 1 was characterized using a JEOL Model JSM-6490 scanning electron microscope (Japan). Figure 2 As shown, the size of Ge-doped ZnSn(OH)6 is between 0.3 and 0.6 μm.

[0076] Experiment 3: XPS characterization

[0077] like Figure 3 As shown in the XPS full spectrum comparison of Example 1 and Comparative Example 1, Ge 3d was assigned at 34.2 eV in Example 1, confirming that Ge ions have been incorporated into ZnSn(OH)6.

[0078] Experiment 4: Characterization of photocatalytic activity

[0079] The performance of the catalyst was evaluated by real-time monitoring of the instantaneous concentration of volatile organic compounds (VOCs) at the ppm level in the reaction chamber using photoacoustic spectroscopy at room temperature. The specific procedure was as follows: four 0.1g samples were weighed onto a 40mm × 100mm rectangular frosted glass slide with rounded corners, uniformly dispersed with a small amount of alcohol, and then dried in a constant-temperature drying oven at 60℃. After cooling to room temperature, the catalyst-loaded glass slide was placed in a 0.34L (200mm × 100mm × 17mm) rectangular continuous-flow reaction chamber, and a layer of quartz glass was placed on top of the chamber to seal it (secured with screws to prevent air leakage). Simultaneously, a 300W commercial mercury lamp was used above the reaction chamber as the ultraviolet light source for the photocatalytic reaction; the initial concentration of pollutants was adjusted by regulating the flow meter in the gas path, and the flow rate of the humidified air was set to 0.5L·min. -1 The flow rate of dry air (0.4 L·min) -1 ) and the flow rate of pollutants (0.1 L·min -1 The sum of these is 0.5 L·min -1 The diluted VOCs pollutant gas is introduced into the reaction chamber. Under dark conditions, after the catalyst reaches adsorption-desorption equilibrium, the light is turned on to carry out the pollutant degradation reaction, and the toluene concentration in the reaction chamber is recorded using a photoacoustic spectrometer.

[0080] Figures 4-9 The experimental process is shown in the photocatalytic activity diagram of toluene. Figure 4It can be seen that the photocatalytic activity of Ge-doped ZnSn(OH)6 photocatalyst for toluene oxidation at 50 ppm is higher than 80%, and the toluene oxidation activity in Examples 1, 4-10 is 100%. In particular, the toluene oxidation activity of the Ge-doped ZnSn(OH)6 photocatalyst prepared in Example 1 rapidly reaches 100% after about 10 minutes. This shows that the incorporation of Ge ions greatly improves the activity of ZnSn(OH)6, and the mineralization rate of toluene is around 120%. Figure 5 This demonstrates its excellent deep mineralization ability for toluene, achieving efficient conversion of toluene to CO2. Furthermore, in different humid air photodegradation tests of toluene, Comparative Example 1 showed the highest degradation activity at 50% humid air, approaching 83%. Figure 6 In Example 1, the degradation of toluene under 50% humid air reached 100% within 10 minutes, with a minimum degradation rate of 80%. Figure 7 It can be seen that Ge-doped ZnSn(OH)6 is less affected by water. We also tested the photocatalytic oxidation activity of the photocatalysts prepared in Example 1, Comparative Examples 2 and 3 for 50 ppm toluene. Figure 8 As shown, the results represent 100%, inactivation, decreased activity followed by inactivation, and then further inactivation. This demonstrates that in wide-bandgap semiconductors, Ge ion doping only affects ZnSn(OH)6, CaCO3 is inactive, and TiO2 is unstable. Furthermore, this application conducted stability tests on Example 1, as shown... Figure 9 As shown, the activity remained at 100% in five cycles within 335 minutes without any decrease, indicating that the Ge-doped ZnSn(OH)6 catalyst prepared by the hydrothermal method has excellent performance, good stability and extremely high efficiency.

[0081] Experiment 5: Electrochemical Characterization

[0082] The impedance of Example 1, Comparative Example 1, and a single GeO2 sample were tested in this invention. Figure 10 As shown, the results indicate that the impedance of Example 1 is much smaller than that of Comparative Example 1 and single GeO2 (the smaller the radius, the smaller the photocatalyst impedance), proving that the catalyst prepared in Example 1 can accelerate the migration rate of charge carriers and enhance the photocatalytic oxidation ability of toluene.

[0083] Experiment 6: Free Radical Test

[0084] like Figure 11As shown, by observing the electron generation of Example 1, Comparative Example 1, and single GeO2 under illumination using TEMPO spin-trapping electron EPR technology, it can be found that the peak value of Example 1 decreases the fastest with increasing lamp-on time. This proves that after introducing Ge ions, ZnSn(OH)6 can generate more electrons and hydroxyl radicals, and better activate toluene. The formation of ·OH was detected by DMPO spin-trapping measurement method, such as... Figure 12 As shown, the peak value of Example 1 is particularly prominent with increasing illumination time, demonstrating that the introduction of Ge ions can promote the generation of ·OH from ZnSn(OH)6. ·OH facilitates the ring-opening reaction of toluene, converting toluene into the benzoic acid intermediate. Benzoic acid has the lowest ring-opening energy barrier, which can help toluene be completely mineralized into CO2; even under the attack of ·OH, toluene can be directly converted into CO2 in one step.

[0085] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a Ge-doped ZnSn(OH)6 photocatalyst, characterized in that, Ge-doped ZnSn(OH)6 photocatalyst was prepared via hydrothermal synthesis using SnCl4·5H2O, Zn(Ac)2·2H2O, alkali metal hydroxide, methylcellulose, and GeO2 as raw materials. The specific preparation steps are as follows: a. Add SnCl4·5H2O, Zn(Ac)2·2H2O, alkali metal hydroxide, methylcellulose and GeO2 to distilled water and stir to obtain a mixture; b. The mixture is placed in a sealed pressure vessel and subjected to a hydrothermal reaction. After the reaction is completed and cooled to room temperature, it is washed, dried and ground to obtain Ge-doped ZnSn(OH)6 photocatalyst crystalline powder.

2. The preparation method according to claim 1, characterized in that, Alkali metal hydroxides are NaOH, KOH, or LiOH.

3. The preparation method according to claim 2, characterized in that, The molar ratio of SnCl4·5H2O, Zn(Ac)2·2H2O, alkali metal hydroxide, and GeO2 is 1:1~1.2:7~8.4:0.07~4.

8.

4. The preparation method according to claim 3, characterized in that, The molar ratio of SnCl4·5H2O, Zn(Ac)2·2H2O, NaOH, and GeO2 is 1:1~1.2:7~8.4:0.12~4.

8.

5. The preparation method according to claim 3, characterized in that, The molar ratio of SnCl4·5H2O, Zn(Ac)2·2H2O, NaOH, and GeO2 is 1:1:7:0.

6.

6. The preparation method according to claim 1, characterized in that, The hydrothermal reaction temperature is raised from room temperature to 160℃~165℃, and then kept at that temperature for 390min~400min.

7. The preparation method according to claim 1, characterized in that, The specific stirring conditions are: 500–800 r / min; 10–20 min.

8. The preparation method according to claim 1, characterized in that, The specific steps of the washing process are as follows: after cooling to room temperature, wash twice each with distilled water and anhydrous ethanol.

9. The preparation method according to claim 1, characterized in that, The drying conditions are specifically: drying at 55℃~65℃ for 6~8 hours.

10. The application of the Ge-doped ZnSn(OH)6 photocatalyst prepared by any one of claims 1-9 in the removal of toluene contaminants or in the preparation of photocatalytic products for removing toluene contaminants.

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