A preparation method of a hierarchical pore double-heterojunction catalyst for enhancing photocatalytic reduction of carbon dioxide

Abstract

The application discloses a preparation method of a hierarchical pore double-heterojunction catalyst for enhancing photothermal catalytic carbon dioxide reduction, and the catalyst is obtained by confining a heterojunction precursor solution in polystyrene template channels with a three-dimensional ordered multilayer opal structure, and then through simple calcination treatment, a hierarchical pore S-type heterojunction / Schottky junction photothermal catalytic material with a macropore-mesopore structure is obtained. Compared with other zero-dimensional / two-dimensional photothermal catalytic materials, the heterojunction structure is expanded to a three-dimensional hierarchical porous frame structure, and the obtained photothermal catalytic material has unique advantages of controllable structure and adjustable loading, and provides abundant active reaction site centers for a photothermal catalytic process.

Description

Technical Field

[0001] This invention relates to the technical field of new energy and chemical materials, and in particular to a method for preparing a hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst that enhances photothermal catalytic CO2 reduction. Background Technology

[0002] Excessive CO2 emissions have led to serious environmental problems, such as the greenhouse effect and climate change. As the Earth's most abundant energy resource, utilizing sunlight as an alternative energy source has become a popular area of ​​scientific research. Since solar radiation mainly consists of heat and light energy, using photothermal catalysis to convert CO2 into high-value-added chemicals will be beneficial for achieving CO2 emission reduction and a green, sustainable development path.

[0003] Specifically, the photothermal catalytic reduction of CO2 generally includes the following steps: ① Light energy absorption and excitation: Under illumination, the catalyst surface absorbs light energy, generating electron-hole pairs and forming excited-state electrons. These high-energy electrons are further transferred to the surface of guest molecules for subsequent chemical reactions. ② CO2 adsorption: CO2 molecules are adsorbed onto the catalyst surface and interact with the excited-state electrons. During adsorption, CO2 molecules may undergo dissociation or charge transfer reactions, generating various intermediate products. ③ Reduction reaction: The CO2 molecules adsorbed on the catalyst surface react with the excited-state electrons and activated surface groups to produce the target product. These products can be carbon-based compounds such as carbon monoxide and methane, or other organic compounds. ④ Product desorption and release: The generated products are desorbed from the catalyst surface and released, completing one round of reduction reaction. These products can be collected and further utilized, or used as intermediates in chemical synthesis or directly as fuel. However, the low redox capacity of photogenerated charge carriers and the rapid recombination between photogenerated electron-hole pairs affect the catalytic performance of the catalyst. Therefore, designing a catalyst that can efficiently enhance the photothermal catalytic CO2 reduction performance is key to achieving CO2 emission reduction and green sustainable development.

[0004] Currently, constructing heterostructures is often an effective strategy for achieving photogenerated charge separation, such as Schottky junctions, van der Waals heterostructures, and Z-type heterostructures. The rational design and control of heterostructures can effectively improve the photothermal conversion efficiency, surface reactivity, electron transport and separation efficiency of catalysts, and expand the types of catalytic reactions, which will improve the stability and cycle life of photothermal catalysts. On the other hand, the structural design of materials also has a significant impact on the catalytic performance of catalysts. For example, the specific surface area and active site density, pore structure and pore size distribution, surface modification and functionalization of materials determine their advantages in catalytic reaction rate, activity, and selectivity, thus providing important support for achieving efficient and sustainable photothermal catalytic reactions. Summary of the Invention

[0005] Designing S-type heterojunction photothermal catalysts is one of the effective ways to enhance photothermal catalytic CO2 reduction. However, the reaction kinetics of single S-type heterojunction catalyst materials are often slow, which severely limits the catalytic performance. To address this, this invention proposes a novel S-type heterojunction / Schottky junction dual heterojunction structure. Driven by both band bending and a built-in electric field, it promotes the rapid generation and transfer of electron-hole pairs. Furthermore, the hot electrons generated based on the localized surface plasmon resonance effect of noble metals drive the rapid surface photothermal catalytic reaction, thus solving the problem of slow reaction kinetics in single heterojunction catalyst materials. In addition, this invention also designs a hierarchical pore structure with highly continuous interconnected channels and constructs a dual heterojunction structure on this special structure, solving the problems of low specific surface area, few active sites, slow interfacial electron transport, and slow substrate and product adsorption-desorption in most current photothermal catalytic materials. The high specific surface area of ​​the hierarchical pore structure increases the contact area with CO2, while the abundant active sites further enhance the catalytic reaction rate. The uniform pore structure not only helps the diffusion rate of reactants on the catalyst surface but also eliminates some of the influences for subsequent investigation of the catalytic mechanism. Finally, the ordered macroporous-mesoporous channels accelerate the movement of electrons at the interface, thereby enhancing the activity and selectivity of the photothermal catalyst for specific reactions.

[0006] To address the aforementioned technical problems, this invention provides a method for preparing a hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst that enhances photothermal catalytic CO2 reduction, comprising the following steps:

[0007] (1) Styrene solution and deionized water were heated and stirred under a nitrogen atmosphere;

[0008] (2) Add potassium persulfate to the mixture obtained in step (1) and heat and stir to obtain an emulsion;

[0009] (3) The emulsion obtained in step (2) is subjected to static drying treatment to obtain a tightly packed polystyrene array;

[0010] (4) Dissolve cerium(III) hexahydrate and indium nitrate in the same molar ratio in water to obtain a precursor solution;

[0011] (5) Add the precursor solution prepared in step (4) to the polystyrene array obtained in step (2) and let it stand at room temperature;

[0012] (6) The precursor material obtained after standing in step (5) is subjected to high-temperature calcination to obtain graded porous In2O3 / CeO2 composite material.

[0013] (7) Dissolve citric acid and chloroauric acid in deionized water to obtain a mixed solution;

[0014] (8) Add the mixed solution obtained in step (7) to the graded pore sample prepared in step (5) and heat and stir.

[0015] (9) The sample prepared in step (8) is centrifuged, washed and dried to obtain the graded pore Au@In2O3 / CeO2 S-type heterojunction / Schottky junction photothermal catalyst.

[0016] As a preferred embodiment of the above technical solution, the preparation method of the hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction provided by the present invention further includes some or all of the following technical features:

[0017] As an improvement to the above technical solution, the ratio of styrene to deionized water in step (1) is 47g:100mL to 50g:100mL; the stirring time is 20 to 40 minutes; and the heating temperature is 70 to 80℃.

[0018] As an improvement to the above technical solution, in step (2), the ratio of potassium persulfate to styrene is 0.32g:47g to 0.4g:50g, the heating temperature is 70 to 80°C, and the reaction time is 6 to 8h.

[0019] As an improvement to the above technical solution, the drying method in step (3) is static drying, and the drying temperature is 45-65℃.

[0020] As an improvement to the above technical solution, the settling time in step (5) is 24 to 48 hours.

[0021] As an improvement to the above technical solution, the heating rate of high-temperature calcination in step (6) is 2-5℃ / min, the temperature is 450-550℃, and the calcination time is 4-6h.

[0022] As an improvement to the above technical solution, in step (7), the ratio range of the graded pore In2O3 / CeO2 composite material, chloroauric acid solution and citric acid solution is: 100mg:2mL:2mL~200mg:4mL:4mL; wherein, the concentration of chloroauric acid solution is 1~1.5mg / mL and the concentration of citric acid solution is 0.45~0.5M.

[0023] As an improvement to the above technical solution, the heating temperature in step (8) is 95-110°C and the reaction time is 10-15 min.

[0024] As an improvement to the above technical solution, the drying temperature in step (9) is 45-65℃ and the drying time is 24-48h.

[0025] A hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst for enhancing photothermal catalytic CO2 reduction, wherein the hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst for enhancing photothermal catalytic CO2 reduction is prepared by any of the methods described above.

[0026] The prepared catalyst material exhibits a uniform large pore size (300 nm) and a high specific surface area of ​​53 m². 2 / g, providing sufficient contact interface and active sites for the adsorption and conversion of carbon dioxide. In photothermal catalysis, the hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst achieved a catalytic yield of 79.15 μmol g. -1 h -1 It is much higher than that of In2O3 (23.49 μmol g). -1 h -1 CeO2 (27.78 μmol g) -1 h -1 ) and In2O3 / CeO2 (57.36 μmol g -1 h -1These results indicate that the presence of the dual heterojunction enhances the separation and transfer of photogenerated electrons, thereby improving its photothermal catalytic performance. Under xenon lamp irradiation, the overall temperature of the hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst rapidly increased from room temperature to 66.5℃, and the catalytic temperature remained almost constant, significantly higher than that of In2O3 (45.6℃), CeO2 (46.6℃), and In2O3 / CeO2 (49.4℃). This is attributed to the stable localized surface plasmon resonance effect of Au nanoparticles. Furthermore, the hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst maintained good photothermal catalytic activity for carbon dioxide after 10 h of cycling, with yields of 79.15, 79.04, and 79.02 μmol g in three tests, respectively. -1 h -1 There was almost no significant change, demonstrating the good catalytic stability of the catalytic material.

[0027] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0028] This invention confines a heterojunction precursor solution within the pores of a polystyrene template with a three-dimensionally ordered multilayer opal structure, followed by simple calcination to obtain a hierarchical porous S-type heterojunction / Schottky junction photothermal catalytic material with a macroporous-mesoporous structure. The development of this hierarchical porous photothermal catalytic material with a composite heterojunction structure provides an effective solution to the problem of slow reaction kinetics in single heterojunction photothermal catalysis. Simultaneously, the hierarchical pore framework provides reliable support for noble metal loading, interfacial electron transfer, guest molecule adsorption, and product desorption, exhibiting excellent catalytic efficiency and high catalytic selectivity. The hierarchical porous dual heterojunction material prepared by this invention is a photothermal catalytic material with great application potential. Furthermore, based on the multi-scale tunability of the material framework—the hierarchical pore structure—this invention can be applied to the construction of other types of dual heterojunction and even multi-heterojunction catalytic systems, thus providing a considerable synthetic route for designing efficient photothermal catalysts for industrial CO2 conversion.

[0029] Compared to single heterojunction photothermal catalysts, this invention couples an S-type heterojunction and a Schottky junction into a single catalyst system. The band-crossed S-type heterojunction, driven by a built-in electric field, band bending, and Coulomb attraction, maximizes the photocatalytic redox capability. Meanwhile, the high-energy hot electrons generated by Au nanoparticles based on the surface plasmon resonance effect accelerate the transfer of photogenerated electrons while releasing heat to the surrounding system. This reduces the activation energy required for molecular activation from a thermocatalytic perspective, thereby enhancing the catalytic reaction activity.

[0030] Secondly, compared with other zero-dimensional / one-dimensional / two-dimensional and composite photothermal catalytic materials, this invention achieves uniform loading of the dual heterojunction precursor solution and construction of a hierarchical pore structure photothermal catalyst by depositing the obtained monodisperse polystyrene microsphere emulsion. This effectively improves the overall specific surface area of ​​the catalyst, the number of reactive sites, the adsorption of guest molecules, and the desorption of products, while reducing the charge transfer resistance at the interface, thereby achieving highly selective conversion of CO2.

[0031] In summary, this invention addresses the issues of slow reaction kinetics and low selectivity in single heterojunction photothermal catalysts by constructing a dual heterojunction catalytic system based on an ordered framework of macropores and mesopores. The preparation method is relatively simple and easy to operate. Furthermore, by controlling the pore size of the template and the spacing between microspheres, the influence of pore size and porosity on catalytic performance can be further explored, thereby achieving the screening of optimal catalytic performance. On the other hand, by changing the composition and concentration of the heterojunction precursor, it is expected to achieve multi-scale control of the built-in electric field in the catalytic system, further optimizing the catalytic performance of the material and providing effective technical support for achieving efficient industrial catalytic CO2 reduction.

[0032] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, the following detailed description is provided in conjunction with preferred embodiments. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0034] Figure 1 The image shows a scanning electron microscope image of the polystyrene microspheres prepared in Example 1, which shows that the synthesized polystyrene microspheres are of uniform size.

[0035] Figure 2 The image shows a scanning electron microscope image of the polystyrene carbon sphere template prepared in Example 1. The results show that the synthesized carbon template has uniform pore size and maintains a typical opal structure.

[0036] Figure 3 The image shows a scanning electron microscope image of the hierarchical porous Au@In2O3 / CeO2 composite material prepared in Example 1. The results show that the catalyst still maintains the original pore size of the template.

[0037] Figure 4The image shown is a transmission electron microscope image of the hierarchical porous Au@In2O3 / CeO2 composite material prepared in Example 1. The results further show that the synthesized Au@In2O3 / CeO2 catalyst material has an ordered hierarchical porous structure with interconnected pores.

[0038] Figure 5 The image shown is a transmission electron microscope image of the hierarchical porous Au@In2O3 / CeO2 composite material prepared in Example 1. The results show the presence of each component of the catalyst material, further confirming the efficient synthesis of the material.

[0039] Figure 6 The image shows the X-ray diffraction (XRD) image of the hierarchical porous Au@In2O3 / CeO2 composite material prepared in Example 2. The results show the characteristic peaks of various components in the catalyst.

[0040] Figure 7 The images show the photocurrent response signals of the Au@In2O3 / CeO2 composite material and its components prepared in Example 3. The results show that the Au@In2O3 / CeO2 composite material has a fast response under illumination and exhibits the highest current response signal value.

[0041] Figure 8 The images show the AC impedance changes of the Au@In2O3 / CeO2 composite material prepared in Example 3 under illumination, along with those of each component material. The results show that the Au@In2O3 / CeO2 composite material exhibits the lowest charge transfer resistance.

[0042] Figure 9 The images show the photothermal catalytic performance of the Au@In2O3 / CeO2 composite material prepared in Example 4 and the catalytic performance of each component material in CO2 reduction. The results show the optimal catalytic efficiency of the Au@In2O3 / CeO2 composite material.

[0043] Figure 10 The images show the stability of the Au@In2O3 / CeO2 composite material prepared in Example 4 under light irradiation over time, and the results show the optimal photothermal effect of the Au@In2O3 / CeO2 composite material.

[0044] Figure 11 The image shows the catalytic stability of the Au@In2O3 / CeO2 composite material prepared in Example 4. The results show that the Au@In2O3 / CeO2 composite material can maintain stable catalytic performance after 10 hours of continuous testing, indicating the excellent cycle life of the material. Detailed Implementation

[0045] The following detailed description of specific embodiments of the present invention is part of this specification. The principles of the present invention are illustrated through examples, and other aspects, features and advantages of the present invention will become apparent from this detailed description.

[0046] This invention relates to a hierarchical porous Au@In2O3 / CeO2 structure for photothermal catalytic CO2 reduction. S-type heterojunction / Schottky junction catalyst and its preparation method: The photothermal catalytic material is prepared by the following method: (1) Styrene and deionized water are added to a three-necked flask, potassium persulfate is added to react fully, and the mixture is stirred under a nitrogen atmosphere to obtain a polystyrene microsphere emulsion with uniform sphere diameter; (2) The above polystyrene microsphere emulsion is dried under static conditions to obtain a polystyrene microsphere array with closely packed stacked pores; (3) A mixed precursor solution containing cerium nitrate hexahydrate, indium nitrate and citric acid is slowly dripped into the above polystyrene microsphere array. After being statically maintained at room temperature, the polystyrene microsphere template is removed by high-temperature calcination under an inert gas to obtain an In2O3 / CeO2 composite material with hierarchical pore structure; (4) The above hierarchical pore In2O3 / CeO2 composite material is added to a chloroauric acid solution and heated and stirred. After drying, Au@In2O3 / CeO2 S-type heterojunction / Schottky junction photothermal catalytic material with hierarchical pore structure can be obtained. Compared to other zero-dimensional / two-dimensional photothermal catalytic materials, this invention extends the heterostructure to a three-dimensional porous framework structure. The resulting photothermal catalytic material exhibits unique advantages such as controllable structure and adjustable loading, providing abundant active reaction site centers for the photothermal catalytic process.

[0047] Unless otherwise specified, all drugs mentioned in the following examples are commercially available chemical drugs.

[0048] Example 1

[0049] A method for preparing a hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst to enhance photothermal catalytic CO2 reduction. The preparation method is as follows:

[0050] (1) Weigh 47g of styrene solution and add it to 100mL of deionized water, and then heat it at 75℃ under a nitrogen atmosphere.

[0051] Heat and stir for 30 minutes.

[0052] (2) Weigh 0.32g of potassium persulfate and add it to step (1). Heat and stir at 75°C for 6 hours.

[0053] (3) The polystyrene emulsion obtained in step (2) is subjected to static drying at 60°C.

[0054] (4) Weigh out cerium(III) hexahydrate and indium nitrate in the same molar ratio, and dissolve them in water to obtain a precursor solution.

[0055] (5) Add the polystyrene microsphere template to the precursor solution in step (4) and then let it stand at room temperature for 24 hours.

[0056] (6) The precursor material in step (5) is subjected to high-temperature calcination at 550°C for 5 hours, with the heating rate maintained at 2°C / min, to obtain the graded porous In2O3 / CeO2 composite material.

[0057] (7) Weigh out citric acid and chloroauric acid and dissolve them in deionized water. The volume of the chloroauric acid solution is 4 mL and the concentration is 1 mg / mL. The volume of the citric acid solution is 4 mL and the concentration is 0.5 M.

[0058] (8) Add the mixed solution obtained in step (7) to 200 mg of graded In2O3 / CeO2 sample in step (5) and heat and stir at 100 °C for 10 min.

[0059] (9) The sample from step (8) was centrifuged and washed, and dried at 60°C for 24 h to obtain the desired grade of Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalytic material.

[0060] Scanning electron microscope (SEM) images of the polystyrene microspheres and carbon templates prepared by the above method are shown below. Figure 1 and Figure 2 As shown, both exhibit typical opal structures with uniform sizes of approximately 300 nm. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of the prepared hierarchical porous Au@In₂O₃ / CeO₂ S-type heterojunction / Schottky junction catalytic materials are shown below. Figure 3 and Figure 4 As shown, it almost perfectly preserves the pore structure of the polystyrene microsphere template used, exhibits an interconnected and ordered macroporous-mesoporous structure, and achieves effective loading of Au nanoparticles on a hierarchical framework structure. Figure 5 ).

[0061] Example 2

[0062] A method for preparing a hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst to enhance photothermal catalytic CO2 reduction. The preparation method is as follows:

[0063] (1) Weigh 47g of styrene solution and 100mL of deionized water and heat and stir them for 30min under a nitrogen atmosphere at 75℃.

[0064] (2) Weigh 0.32g of potassium persulfate and add it to step (1). Heat and stir at 75°C for 6 hours.

[0065] (3) The polystyrene emulsion obtained in step (2) is subjected to static drying at 60°C.

[0066] (4) Weigh out cerium(III) hexahydrate and indium nitrate in the same molar ratio, and dissolve them in water to obtain a precursor solution.

[0067] (5) Add the polystyrene microsphere template to the precursor solution in step (4) and then let it stand at room temperature for 24 hours.

[0068] (6) The precursor material in step (5) is subjected to high-temperature calcination at 550°C for 5 hours, with the heating rate maintained at 2°C / min, to obtain the graded porous In2O3 / CeO2 composite material.

[0069] (7) Weigh out citric acid and chloroauric acid and dissolve them in deionized water. The volume of the chloroauric acid solution is 4 mL and the concentration is 1 mg / mL. The volume of the citric acid solution is 4 mL and the concentration is 0.5 M.

[0070] (8) Add the mixed solution obtained in step (7) to 200 mg of graded In2O3 / CeO2 sample in step (5) and heat and stir at 100 °C for 10 min.

[0071] (9) The sample from step (8) was centrifuged and washed, and dried at 60°C for 24 h to obtain the desired grade of Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalytic material.

[0072] like Figure 6 As shown, XRD characterization analysis of the prepared material indicates that the catalyst is mainly composed of In2O3, CeO2 and Au with good crystallinity.

[0073] Example 3

[0074] A method for preparing a hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst to enhance photothermal catalytic CO2 reduction. The preparation method is as follows:

[0075] (1) Weigh 47g of styrene solution and 100mL of deionized water and heat and stir them for 30min under a nitrogen atmosphere at 75℃.

[0076] (2) Weigh 0.32g of potassium persulfate and add it to step (1). Heat and stir at 75°C for 6 hours.

[0077] (3) The polystyrene emulsion obtained in step (2) is subjected to static drying at 60°C.

[0078] (4) Weigh out cerium(III) hexahydrate and indium nitrate in the same molar ratio, and dissolve them in water to obtain a precursor solution.

[0079] (5) Add the polystyrene microsphere template to the precursor solution in step (4) and then let it stand at room temperature for 24 hours.

[0080] (6) The precursor material in step (5) is subjected to high-temperature calcination at 550°C for 5 hours, with the heating rate maintained at 2°C / min, to obtain the graded porous In2O3 / CeO2 composite material.

[0081] (7) Weigh out citric acid and chloroauric acid and dissolve them in deionized water. The volume of the chloroauric acid solution is 4 mL and the concentration is 1 mg / mL. The volume of the citric acid solution is 4 mL and the concentration is 0.5 M.

[0082] (8) Add the mixed solution obtained in step (7) to 200 mg of graded In2O3 / CeO2 sample in step (5) and heat and stir at 100 °C for 10 min.

[0083] (9) The sample from step (8) was centrifuged and washed, and dried at 60°C for 24 h to obtain the desired grade of Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalytic material.

[0084] like Figure 7 and Figure 8 As shown, the photoelectric performance of the hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalytic material prepared by the above method was tested. The results showed that the introduction of the S-type heterojunction and Schottky junction achieved effective separation of photogenerated carriers, and the construction of the hierarchical porous structure effectively improved the transport of carriers at the interface, thus exhibiting the highest photocurrent response signal and the lowest charge transfer resistance.

[0085] Example 4

[0086] A method for preparing a hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalyst to enhance photothermal catalytic CO2 reduction. The preparation method is as follows:

[0087] (1) Weigh 47g of styrene solution and 100mL of deionized water and heat and stir them for 30min under a nitrogen atmosphere at 75℃.

[0088] (2) Weigh 0.32g of potassium persulfate and add it to step (1). Heat and stir at 75°C for 6 hours.

[0089] (3) The polystyrene emulsion obtained in step (2) is subjected to static drying at 60°C.

[0090] (4) Weigh out cerium(III) hexahydrate and indium nitrate in the same molar ratio, and dissolve them in water to obtain a precursor solution.

[0091] (5) Add the polystyrene microsphere template to the precursor solution in step (4) and then let it stand at room temperature for 24 hours.

[0092] (6) The precursor material in step (5) is subjected to high-temperature calcination at 550°C for 5 hours, with the heating rate maintained at 2°C / min, to obtain the graded porous In2O3 / CeO2 composite material.

[0093] (7) Weigh out citric acid and chloroauric acid and dissolve them in deionized water. The volume of the chloroauric acid solution is 4 mL and the concentration is 1 mg / mL. The volume of the citric acid solution is 4 mL and the concentration is 0.5 M.

[0094] (8) Add the mixed solution obtained in step (7) to 200 mg of graded In2O3 / CeO2 sample in step (5) and heat and stir at 100 °C for 10 min.

[0095] (9) The sample from step (8) was centrifuged and washed, and dried at 60°C for 24 h to obtain the desired grade of Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalytic material.

[0096] like Figure 9 As shown, the photothermal catalytic CO2 reduction performance of the hierarchical porous Au@In2O3 / CeO2 S-type heterojunction / Schottky junction catalytic material prepared by the above method was tested. The Au@In2O3 / CeO2 material exhibited the best catalytic conversion performance, indicating that the introduction of the hierarchical porous structure provides additional active reaction sites for the catalytic reaction. The photothermal effect of the material is characterized as follows: Figure 10 As shown, due to the introduction of Au nanoparticles, the Au@In2O3 / CeO2 material exhibits the best photothermal effect due to the thermal effect brought about by the high-energy hot electrons excited by its local surface plasmon resonance effect. Furthermore, the catalytic stability of the hierarchical porous Au@In2O3 / CeO2 material is as follows: Figure 11 As shown, the material maintains its catalytic performance during a continuous catalytic reaction over 10 hours, indicating its good catalytic lifespan.

[0097] All the raw materials listed in this invention, as well as the upper and lower limits and ranges of the raw materials and the upper and lower limits and ranges of the process parameters (such as temperature, time, etc.), can realize this invention. Examples are not listed one by one here.

[0098] The above description is merely a preferred embodiment of the present invention, and should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction, characterized in that, It includes the following steps: (1) Styrene solution and deionized water were heated and stirred under a nitrogen atmosphere; (2) Add potassium persulfate to the mixture obtained in step (1) and heat and stir to obtain an emulsion; (3) The emulsion obtained in step (2) is subjected to static drying treatment to obtain a tightly packed polystyrene array; (4) Dissolve cerium(III) hexahydrate and indium nitrate in the same molar ratio in water to obtain a precursor solution; (5) Add the precursor solution prepared in step (4) to the polystyrene array obtained in step (3) and let it stand at room temperature to obtain the precursor material; (6) The precursor material obtained after standing in step (5) is subjected to high-temperature calcination to obtain graded porous In2O3 / CeO2 composite material. (7) Dissolve citric acid and chloroauric acid in deionized water to obtain a mixed solution; (8) Add the mixed solution obtained in step (7) to the graded pore sample prepared in step (6) and heat and stir. (9) The sample prepared in step (8) is centrifuged, washed and dried to obtain the hierarchical Au@In2O3 / CeO2S heterojunction / Schottky junction photothermal catalyst.

2. The method for preparing the hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 1, characterized in that: In step (1), the ratio of styrene to deionized water is 47 g: 100 mL to 50 g: 100 mL; the stirring time is 20 to 40 min; and the heating temperature is 70 to 80 °C. In step (2), the ratio of potassium persulfate to styrene is 0.32 g: 47 g to 0.4 g: 50 g; the heating temperature is 70 to 80 °C; and the reaction time is 6 to 8 h.

3. The method for preparing the hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 1, characterized in that: The drying method in step (3) is static drying, and the drying temperature is 45~65℃.

4. The method for preparing the hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 1, characterized in that: The settling time for step (5) is 24~48 h.

5. The method for preparing the hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 1, characterized in that: In step (6), the heating rate of high-temperature calcination is 2~5℃ / min, the temperature is 450~550℃, and the calcination time is 4~6 h.

6. The method for preparing the hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 1, characterized in that: In step (8), the ratio range of the graded porous In2O3 / CeO2 composite material, chloroauric acid solution, and citric acid solution is: 100 mg: 2 mL: 2 mL ~ 200 mg: 4 mL: 4 mL; wherein, the concentration of chloroauric acid solution is 1 ~ 1.5 mg / mL, and the concentration of citric acid solution is 0.45 ~ 0.5 M.

7. The method for preparing the hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 1, characterized in that: In step (8), the heating temperature is 95~110℃ and the reaction time is 10~15min.

8. The method for preparing the hierarchical porous Au@In2O3 / CeO2S-type heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 1, characterized in that: In step (9), the drying temperature is 45~65℃ and the drying time is 24~48h.

9. A hierarchical porous Au@In2O3 / CeO2S heterojunction / Schottky junction catalyst for enhancing photothermal catalytic CO2 reduction, characterized in that: The hierarchical porous Au@In2O3 / CeO2S heterojunction / Schottky junction catalyst for enhancing photothermal catalytic CO2 reduction is prepared by any one of the methods in claims 1-8.

10. The hierarchical porous Au@In2O3 / CeO2S heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction as described in claim 9, characterized in that: The hierarchical porous Au@In2O3 / CeO2S heterojunction / Schottky junction catalyst for enhanced photothermal catalytic CO2 reduction has a uniform pore size of 300 nm and a specific surface area of ​​53 m². 2 / g, catalytic carbon monoxide yield was 79.15 μmol g. -1 h -1 Under xenon lamp irradiation, the overall temperature rapidly increased from room temperature to 66.5℃, and after three 10-hour reaction cycles, the carbon monoxide yield remained at 79.0 μmol g. -1 h -1 above.

Images