A photocatalyst, a method for preparing the same, and use thereof

Abstract

The application belongs to the technical field of photocatalysis, and provides a photocatalyst, a preparation method and application thereof.The photocatalyst comprises a carrier and a load on the carrier; the carrier comprises aluminum-doped strontium titanate, denoted as Al:STO; and the load comprises tin oxide.The loaded tin oxide can take into account the optimization of charge flow direction, selective reaction interface and surface chemical environment, can realize efficient photo-generated electron-hole separation and serve as an active site for H2O2 production, and further realize high selectivity and efficient photocatalytic synthesis of H2O2.Meanwhile, the heterostructure formed by loading tin oxide on Al:STO is beneficial to spatial separation of oxidation sites and reduction sites, and further cooperates with the relatively inert surface of tin oxide to effectively inhibit the decomposition of H2O2.The above factors jointly act, can significantly improve the problem of ineffective decomposition of H2O2 generated by photocatalysis, and further make the steady-state concentration and net output rate of H2O2 obtain significant improvement.

Description

Technical Field

[0001] This invention belongs to the field of photocatalysis technology, and relates to a photocatalyst, its preparation method and application. Background Technology

[0002] Hydrogen peroxide (H2O2), as an environmentally friendly green oxidant, is widely used in chemical, environmental protection, pharmaceutical, and electronic cleaning fields. Currently, its industrial production still mainly relies on the anthraquinone process, which is energy-intensive, multi-step, and produces harmful byproducts. Therefore, developing green and sustainable synthetic routes is urgently needed.

[0003] Photocatalysis, driven by solar energy, uses water and oxygen as raw materials to synthesize H2O2 through oxygen reduction reaction (ORR) or water oxidation reaction (WOR) at ambient temperature and pressure. Due to its mild conditions and environmental friendliness, it has become a promising alternative. The core of this technology lies in developing efficient, stable, and visible-light-responsive photocatalysts.

[0004] Strontium titanate (SrTiO3, abbreviated as STO), as a typical perovskite semiconductor, possesses a suitable conduction band position (~0.8V vs. NHE, pH=7), good chemical stability, and low toxicity. Its conduction band potential is sufficient to drive the reduction of O2 to H2O2. However, intrinsic SrTiO3 has a wide band gap (approximately 3.2 eV), absorbing only ultraviolet light, resulting in a solar light utilization rate of less than 5%. Simultaneously, its photogenerated carrier recombination rate is fast, and the surface active sites are insufficient, leading to a low quantum efficiency. To expand the photoresponse range and improve charge separation efficiency, researchers commonly employ elemental doping strategies. Among these, aluminum (Al) doping can introduce shallow donor levels to modulate the Fermi level, enhancing n-type conductivity and potentially inducing lattice distortion to suppress electron-hole recombination, thereby improving photocatalytic performance to some extent.

[0005] Despite this, the photocatalytic system based on aluminum-doped strontium titanate in the synthesis of H2O2 still generally faces the problem of severe ineffective decomposition of the target product H2O2 on the catalyst surface, resulting in a net yield and accumulation concentration far lower than theoretically expected. Specifically, although aluminum doping can improve the conductivity of SrTiO3 to some extent and introduce defect energy levels, it fails to fundamentally solve the problem of rapid recombination of photogenerated electrons and holes on the material surface. More importantly, the intrinsic or doped surface still lacks an effective mechanism for spatially oriented separation of the two types of charge carriers, which poses a hidden danger for the subsequent decomposition reaction of the product. Secondly, the catalyst surface lacks active sites for selective stabilization of H2O2, and the catalyst surface simultaneously provides dual channels for the oxidative and reductive decomposition of H2O2, which means that the consumption rate of H2O2 may be close to or even exceed its generation rate, resulting in low net yield. Furthermore, aluminum doping may introduce uncontrollable surface states or defects. These defect states, while acting as charge trapping centers, may also become active sites for catalyzing the homogeneous or heterogeneous decomposition of H2O2, thereby exacerbating side reactions.

[0006] The aforementioned problems severely restrict the practical application efficiency of the aluminum-doped strontium titanate photocatalytic system in the field of photocatalytic synthesis of H2O2. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of this invention is to provide a photocatalyst, its preparation method, and its uses. The photocatalyst includes a support and a loading material supported on the support; the support includes aluminum-doped strontium titanate; and the loading material includes tin oxide. By loading tin oxide onto aluminum-doped strontium titanate, the decomposition of hydrogen peroxide can be effectively passivated, thereby significantly improving the net yield rate of photocatalytic synthesis of hydrogen peroxide.

[0008] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a photocatalyst, the photocatalyst comprising a support and a loading material supported on the support; the support comprising aluminum-doped strontium titanate; and the loading material comprising tin oxide.

[0009] The photocatalyst described in this invention comprises tin oxide supported on aluminum-doped strontium titanate. The tin oxide support effectively passivates the decomposition of hydrogen peroxide (H2O2), thereby significantly improving its net yield rate as a photocatalyst for hydrogen peroxide synthesis. Specifically, tin oxide (such as SnO2) possesses extremely high electron mobility and a relatively negative conduction band position. When it forms a tight heterojunction with aluminum-doped strontium titanate (Al:STO), the energy band bends under the drive of the built-in electric field at the interface. Photogenerated electrons then migrate directionally from the conduction band of tin oxide to Al:STO and combine with its holes. Ultimately, the photogenerated electrons of Al:STO remain in its conduction band, while the holes of tin oxide remain in its valence band. This process achieves efficient spatial separation of photogenerated carriers. The enhanced charge separation and directional migration lay a crucial charge distribution foundation for the subsequent photocatalytic synthesis of H2O2. Secondly, compared to some transition metal ions, the surface of tin oxide lacks highly efficient active sites for catalyzing the disproportionation or reductive decomposition of H2O2. Meanwhile, tin oxide can serve as a reaction site for the production of H2O2 via WOR, allowing highly oxidizing holes to be consumed promptly, thus significantly blocking the path of H2O2 contact with holes and effectively inhibiting its oxidative decomposition. Furthermore, electrons enriched on SrTiO3 tend to continuously reduce O2 to generate H2O2 rather than attacking already generated H2O2, further effectively inhibiting its reductive decomposition. Third, Al doping in the support helps optimize the surface acidity and alkalinity of SrTiO3, and the surface properties of tin oxide are generally different from those of strontium titanate. Therefore, a suitable surface chemical environment is conducive to the desorption and stable existence of H2O2, preventing its excessive adsorption on active sites and subsequent decomposition. Thus, the tin oxide loading constructs a spatially separated "production-protection" nanostructure to effectively passivate the decomposition of H2O2, thereby promoting net accumulation and significantly increasing the net production rate of H2O2 under the same illumination conditions.

[0010] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.

[0011] As a preferred embodiment of the present invention, the mass of the loading material accounts for 0.03% to 5% of the mass of the carrier. Exemplarily, it can be 0.03%, 0.05%, 0.08%, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, or 5%, etc. In this invention, the mass of the loading material relative to the mass of the carrier is the loading amount of the loading material. If the tin oxide loading amount is too low, it cannot form an effective coverage on the carrier surface, resulting in too few heterojunction interfaces and a weak passivation effect on hydrogen peroxide; if the tin oxide loading amount is too high, excessive or thick tin oxide will cover the active surface of Al:STO, which will instead reduce the H2O2 production rate.

[0012] As a preferred embodiment of the present invention, the particle size of the support ranges from 0.1 μm to 3 μm, for example, it can be 0.1 μm, 0.3 μm, 0.5 μm, 0.8 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, or 3 μm. In the present invention, when the support particle size is too small, the specific surface area and surface energy increase significantly, and the particles are prone to agglomeration, thus hindering mass transfer; when the support particle size is too large, the number of tin oxide available for loading and the number of active sites for surface reactions are too small, and the probability of bulk recombination of photogenerated electrons and holes during the long migration path to the surface increases, which easily leads to low photocatalytic activity.

[0013] As a preferred embodiment of the present invention, the particle size of the loaded material is smaller than that of the carrier, and the particle size range of the loaded material is 1 nm to 100 nm, for example, it can be 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 30 nm, 50 nm, 80 nm, or 100 nm, etc. That is, the tin oxide loaded in the present invention is nano-tin oxide particles.

[0014] As a preferred embodiment of the present invention, in the aluminum-doped strontium titanate, the doping amount of aluminum is expressed as the molar amount of aluminum oxide, and the molar amount of aluminum oxide is 0.1% to 4% of the molar amount of strontium titanate. For example, it can be 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.3%, 1.5%, 2%, 2.5%, 2.8%, 3%, 3.3%, 3.5%, 3.8%, or 4.0%, etc., preferably 0.5% to 4%. In the present invention, if the aluminum doping amount in the Al:STO support is too small, the regulation effect on the electronic structure of SrTiO3 is insufficient, and it is impossible to effectively increase the carrier concentration or introduce suitable defect energy levels to improve charge separation efficiency, resulting in insufficient photocatalytic activity of the support. When an excessively high concentration of aluminum ions is introduced for doping, it may destroy the crystal structure of SrTiO3, generating a large number of lattice distortions and defects, becoming a strong photogenerated electron-hole pair recombination center. Excessive doping may even affect its band matching with tin oxide, thereby weakening the charge separation driving force of the heterojunction.

[0015] Secondly, the present invention provides a method for preparing the photocatalyst described in the first aspect, the method comprising the following steps: Provide or prepare aluminum-doped strontium titanate; disperse and mix a tin source and the aluminum-doped strontium titanate in water to obtain a mixed dispersion; The mixed dispersion was subjected to a hydrothermal reaction to generate tin oxide, which was then loaded onto aluminum-doped strontium titanate to obtain a photocatalyst.

[0016] As a preferred embodiment of the present invention, the tin source comprises tin chloride. The loading of tin oxide in the photocatalyst can be adjusted by controlling the amount of tin source relative to aluminum-doped strontium titanate.

[0017] As a preferred embodiment of the present invention, the dispersion and mixing method includes ultrasonication and / or stirring.

[0018] As a preferred embodiment of the present invention, the concentration of aluminum-doped strontium titanate in the mixed dispersion is 5 mg / mL to 30 mg / mL. For example, it can be 5 mg / mL, 8 mg / mL, 10 mg / mL, 13 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 28 mg / mL, or 30 mg / mL, etc.

[0019] As a preferred technical solution of the present invention, the temperature of the hydrothermal reaction is 160℃~200℃, for example, it can be 160℃, 170℃, 180℃, 190℃ or 200℃, etc., and the time is 7h~13h, for example, it can be 7h, 9h, 10h, 11h or 13h.

[0020] As a preferred technical solution of the present invention, after the hydrothermal reaction is completed, solid-liquid separation, washing and drying are performed in sequence to obtain the photocatalyst.

[0021] Preferably, the solid-liquid separation method includes centrifugation.

[0022] Preferably, the washing method includes washing with deionized water and ethanol at least three times each.

[0023] Preferably, the drying method includes vacuum drying at 50℃~70℃, for example, 50℃, 55℃, 60℃, 65℃ or 70℃; the vacuum drying time is 8h~16h, for example, 8h, 9h, 10h, 12h, 14h or 16h.

[0024] This invention does not specifically limit the method for preparing aluminum-doped strontium titanate. Exemplarily, it can be carried out by the following method: mixing SrTiO3 with an aluminum source to obtain a mixture; mixing the mixture with a molten salt medium and then calcining it to obtain aluminum-doped strontium titanate.

[0025] Preferably, the aluminum source comprises aluminum oxide (Al2O3). The doping amount of aluminum is controlled by controlling the amount of aluminum oxide relative to SrTiO3.

[0026] Preferably, the molten salt medium comprises strontium chloride (SrCl2). Using SrCl2 helps to avoid the introduction of cationic impurities.

[0027] Preferably, the heating rate of the calcination is 5℃ / min to 20℃ / min, for example, it can be 5℃ / min, 8℃ / min, 10℃ / min, 13℃ / min, 15℃ / min or 20℃ / min, etc.; the holding temperature is 1000℃ to 1200℃, for example, it can be 1000℃, 1050℃, 1100℃, 1150℃ or 1200℃, etc.; the holding time is 5h to 20h, for example, it can be 5h, 8h, 10h, 15h, 18h or 20h, etc.

[0028] Preferably, after the calcination is completed, the calcined product is washed with water until chloride ions are no longer detectable in the washing solution (for example, AgNO3 solution can be added to observe that no white precipitate is produced), and then dried to obtain aluminum-doped strontium titanate.

[0029] Preferably, the drying temperature is 140℃~160℃, for example, it can be 140℃, 145℃, 150℃, 155℃ or 160℃, etc.; the time is 4h~8h, for example, it can be 4h, 5h, 6h, 7h or 8h, etc.

[0030] Thirdly, the present invention provides an use of the photocatalyst described in the second aspect, the use including the photocatalytic synthesis of hydrogen peroxide.

[0031] It should be noted that, due to space limitations and to avoid redundancy, this invention does not exhaustively list all point values ​​within the above numerical range, but it is not limited to the listed values ​​either; other unlisted values ​​within the above numerical range are also applicable.

[0032] Compared with existing technical solutions, the present invention has at least the following beneficial effects: The photocatalyst provided by this invention, by loading tin oxide onto an aluminum-doped strontium titanate support, can effectively passivate the decomposition of hydrogen peroxide (H2O2), thereby significantly improving the net yield rate of photocatalytic hydrogen peroxide synthesis. The loaded tin oxide facilitates the optimization of charge flow, selective reaction interface, and surface chemical environment, promoting highly selective and efficient photocatalytic synthesis of H2O2. Simultaneously, the heterostructure formed by tin oxide loaded on the Al:STO support helps physically isolate strongly oxidizing holes from photogenerated electrons. This effect, combined with the relatively inert surface of tin oxide, further inhibits the decomposition of H2O2. The combined effect of these factors significantly improves the problem of ineffective decomposition of photocatalytically generated H2O2, thereby significantly enhancing the steady-state concentration and net yield rate of H2O2. Attached Figure Description

[0033] Figure 1 This is a scanning electron microscope (SEM) image of the aluminum-doped strontium titanate obtained in Example 1.

[0034] Figure 2 This is a scanning electron microscope image of the photocatalyst obtained in Example 1.

[0035] Figure 3 This is a graph showing the production rate of hydrogen peroxide synthesized by photocatalysis using the photocatalysts obtained in Examples 1 to 7 and Comparative Examples 1 and 2.

[0036] Figure 4 This is a graph showing the production rate of hydrogen peroxide synthesized by photocatalysis using the photocatalysts obtained in Examples 1, 8 to 11 and Comparative Example 1.

[0037] Figure 5 The graph shows the decomposition rate test results of the photocatalysts obtained in Example 1 and Comparative Example 1, as well as the blank control group of pure hydrogen peroxide. Detailed Implementation

[0038] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0039] Those skilled in the art will understand that the embodiments described are merely illustrative of the invention and should not be construed as limiting the invention.

[0040] Example 1 This embodiment provides a photocatalyst, which comprises a support and a loaded material on the support; the support is aluminum-doped strontium titanate, and the molar amount of aluminum doping is expressed as 2% of the molar amount of aluminum oxide; in this embodiment, the specific doping amount of aluminum-doped strontium titanate is denoted as 2Al:STO; the loaded material is tin oxide (i.e., SnO2), and the mass (loading amount) of SnO2 accounts for 1% of the mass of the 2Al:STO; Figure 1 The image shown is a scanning electron microscope (SEM) image of 2Al:STO. It can be seen that 2Al:STO exhibits excellent crystallinity, with cubic particles and smooth surfaces in the magnified image. Particle size analysis shows that the particle size range of 2Al:STO is 0.2 μm to 2.8 μm. Figure 2 The image shown is a scanning electron microscope (SEM) image of the photocatalyst. From the magnified image, it can be seen that the surface of 2Al:STO is covered with nanoparticles, thus the surface is relatively... Figure 1 The roughness shown proves that SnO2 was successfully loaded onto 2Al:STO. This photocatalyst is tin oxide-supported aluminum-doped strontium titanate, denoted as 1SnO2-2Al:STO.

[0041] This embodiment also provides a method for preparing the photocatalyst, including the following steps: S1. Preparation of 2Al:STO using SrTiO3 (abbreviated as STO), SrCl2, and Al2O3 as raw materials: First, STO and Al2O3 nanoparticles were thoroughly mixed, with the amount of Al2O3 controlled at 2% of the molar amount of STO, to obtain a homogeneous mixture. Then, the mixture was thoroughly mixed with SrCl2 and placed in an alumina crucible, heated to 1100℃ at a heating rate of 10℃ / min, and calcined for 10h. After calcination, the mixture was cooled to room temperature, washed with deionized water, and centrifuged until no white precipitate appeared after adding AgNO3 solution to the supernatant. The centrifuged mixture was then dried in an oven at 150℃ for 6h to obtain 2Al:STO. S2. Supported tin oxide: First, 500 mg of 2Al:STO was weighed and dispersed in 50 mL of deionized water. The mixture was sonicated for 30 min in an ultrasonic machine. Then, tin source SnCl2 was added, and the amount added was controlled according to the Sn doping amount of 1%. After stirring for another 30 min, the mixture was transferred to a 100 mL polytetrafluoroethylene reaction liner and placed in an oven for hydrothermal reaction at 180 °C for 10 h. After the reaction was completed and cooled to room temperature, the sample was washed with deionized water and ethanol three times each. Finally, the washed sample was placed in a vacuum drying oven at 60 °C and dried for 12 h to obtain the photocatalyst 1SnO2-2Al:STO.

[0042] Example 2 The difference from Example 1 is that in step S2, the amount of tin source SnCl2 is adjusted so that the Sn doping amount is adjusted from 1% to 0.2%, and the final photocatalyst is denoted as 0.2SnO2-2Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0043] Example 3 The difference from Example 1 is that in step S2, the amount of tin source SnCl2 is adjusted so that the Sn doping amount is changed from 1% to 0.5%, and the final photocatalyst is denoted as 0.5SnO2-2Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0044] Example 4 The difference from Example 1 is that in step S2, the amount of tin source SnCl2 is adjusted so that the Sn doping amount is adjusted from 1% to 3%, and the final photocatalyst is denoted as 3SnO2-2Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0045] Example 5 The difference from Example 1 is that in step S2, the amount of tin source SnCl2 is adjusted so that the Sn doping amount is adjusted from 1% to 5%, and the final photocatalyst is denoted as 5SnO2-2Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0046] Example 6 The difference from Example 1 is that in step S2, the amount of tin source SnCl2 is adjusted so that the Sn doping amount is adjusted from 1% to 0.01%, and the final photocatalyst is denoted as 0.01SnO2-2Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0047] Example 7 The difference from Example 1 is that in step S2, the amount of tin source SnCl2 is adjusted so that the Sn doping amount is adjusted from 1% to 8%, and the final photocatalyst is denoted as 8SnO2-2Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0048] Example 8 The difference from Example 1 is that an aluminum-doped strontium titanate with a different aluminum doping amount than in Example 1 is used as the carrier. That is, in this example, the aluminum doping amount is calculated as the molar amount of aluminum oxide, and the molar amount of aluminum oxide is 0.1% of the molar amount of strontium titanate. The resulting photocatalyst is denoted as 1SnO2-0.1Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0049] Example 9 The difference from Example 1 is that an aluminum-doped strontium titanate with a different aluminum doping amount than in Example 1 is used as the support. That is, in this example, the aluminum doping amount is calculated in terms of the molar amount of aluminum oxide, and the molar amount of aluminum oxide is 0.5% of the molar amount of strontium titanate. The resulting photocatalyst is denoted as 1SnO2-0.5Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0050] Example 10 The difference from Example 1 is that an aluminum-doped strontium titanate with a different aluminum doping amount than in Example 1 is used as the support. That is, in this example, the aluminum doping amount is calculated in terms of the molar amount of aluminum oxide, and the molar amount of aluminum oxide is 3% of the molar amount of strontium titanate. The resulting photocatalyst is denoted as 1SnO2-3Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0051] Example 11 The difference from Example 1 is that an aluminum-doped strontium titanate with a different aluminum doping amount than in Example 1 is used as the carrier. That is, in this example, the aluminum doping amount is calculated in terms of the molar amount of aluminum oxide, and the molar amount of aluminum oxide is 4% of the molar amount of strontium titanate. The resulting photocatalyst is denoted as 1SnO2-4Al:STO. Apart from the above, the other conditions are exactly the same as in Example 1.

[0052] Comparative Example 1 This comparative example uses 2Al:STO from Example 1 as a photocatalyst for subsequent tests.

[0053] Comparative Example 2 The difference from Example 1 is that the loading material is replaced by zinc oxide (ZnO) instead of tin oxide, that is, in step S2, the tin source SnCl2 is replaced by the zinc source ZnCl2. The final photocatalyst is denoted as 1ZnO-2Al:STO. Apart from the above, the other conditions are exactly the same as those in Example 1.

[0054] Characterization and testing: I. The photocatalysts obtained in the examples and comparative examples were tested for photocatalytic synthesis of hydrogen peroxide: All catalyst performance tests were conducted with AM1.5 (100mW·cm⁻¹) catalyst. -2 The reaction was carried out in a light source system. 5 mg of catalyst was weighed and dispersed in 100 mL of water, with oxygen as the oxygen source. After adsorption-desorption equilibrium was reached in the dark, the light source was turned on, and samples were taken every 30 minutes. The yield of hydrogen peroxide was detected by the peroxidase colorimetric method.

[0055] like Figure 3 The figures show the test results of the photocatalysts obtained in Examples 1 to 7, and Comparative Examples 1 and 2 for the synthesis of hydrogen peroxide. It can be seen that compared with Comparative Example 1 without loading or Comparative Example 2 with zinc oxide loading, the hydrogen peroxide production rate of the present invention is significantly improved after loading an appropriate amount of tin oxide. Moreover, the loading amount of tin oxide affects the performance of the synthesized hydrogen peroxide. The loading amount of tin oxide is preferably 0.5% to 2%, and more preferably 1%, which has a great improving effect.

[0056] like Figure 4 The results shown are the synthesis hydrogen peroxide test results of the photocatalysts obtained in Examples 1, 8 to 11 and Comparative Example 1. It can be seen that the amount of aluminum doping in the support will affect the synergistic effect with the supported tin oxide to a certain extent. The amount of aluminum doping in strontium titanate is preferably 1.5% to 2.5%, and more preferably 1.8% to 2.2%.

[0057] II. The photocatalysts obtained in the examples and comparative examples were tested for their hydrogen peroxide decomposition rates: 5 mg of catalyst was dispersed in 100 mL of commercial hydrogen peroxide solution, and nitrogen gas was introduced into the reaction system to eliminate the influence of oxygen in the air. The system was then irradiated under light conditions, and the hydrogen peroxide content was measured every 15 min.

[0058] like Figure 5The figure shows the decomposition rate results of pure hydrogen peroxide using the photocatalysts obtained in Example 1 and Comparative Example 1, as well as the blank control group. It can be seen that, under dark conditions, the decomposition rate of the photocatalyst obtained in Example 1 is comparable to the self-decomposition rate of pure H2O2 under illumination. Furthermore, compared to strontium titanate without tin oxide loading, the decomposition rate of H2O2 decreases significantly under illumination (UV-vis), demonstrating that tin oxide loading can effectively passivate the decomposition of H2O2, thereby improving the performance of the photocatalyst in synthesizing hydrogen peroxide.

[0059] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0060] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0061] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A photocatalyst, characterized in that, The photocatalyst includes a support and a loading material supported on the support; the support includes aluminum-doped strontium titanate; and the loading material includes tin oxide.

2. The photocatalyst according to claim 1, characterized in that, The mass of the load accounts for 0.03% to 5% of the mass of the carrier.

3. The photocatalyst according to claim 1 or 2, characterized in that, The particle size range of the carrier is 0.1 μm to 3 μm; Preferably, the particle size of the loaded material is smaller than the particle size of the carrier, and the particle size range of the loaded material is 1 nm to 100 nm.

4. The photocatalyst according to any one of claims 1-3, characterized in that, In the aluminum-doped strontium titanate, the amount of aluminum doping is expressed as the molar amount of aluminum oxide, and the molar amount of aluminum oxide is 0.1% to 4% of the molar amount of strontium titanate.

5. A method for preparing a photocatalyst according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: Provide or prepare aluminum-doped strontium titanate; disperse and mix a tin source and the aluminum-doped strontium titanate in water to obtain a mixed dispersion; The mixed dispersion was subjected to a hydrothermal reaction to generate tin oxide, which was then loaded onto aluminum-doped strontium titanate to obtain a photocatalyst.

6. The method for preparing the photocatalyst according to claim 5, characterized in that, The tin source includes tin chloride.

7. The method for preparing the photocatalyst according to claim 5 or 6, characterized in that, The dispersion and mixing method includes ultrasonication and / or stirring; Preferably, the concentration of aluminum-doped strontium titanate in the mixed dispersion is 5 mg / mL to 30 mg / mL.

8. The method for preparing the photocatalyst according to any one of claims 5-7, characterized in that, The hydrothermal reaction is carried out at a temperature of 160℃ to 200℃ for a duration of 7 to 13 hours.

9. The method for preparing the photocatalyst according to any one of claims 5-8, characterized in that, After the hydrothermal reaction is completed, solid-liquid separation, washing and drying are performed sequentially to obtain the photocatalyst; Preferably, the solid-liquid separation method includes centrifugation; Preferably, the washing method includes washing with deionized water and ethanol at least three times each; Preferably, the drying method includes vacuum drying at 50°C to 70°C for 8 to 16 hours.

10. The use of a photocatalyst, characterized in that, The use includes using the photocatalyst according to any one of claims 1-4 or the photocatalyst according to any one of claims 5-9 for the photocatalytic synthesis of hydrogen peroxide.

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