Photoelectric catalyst as well as preparation method, electrode and application thereof

Abstract

The invention relates to the technical field of photoelectrocatalysis of CO2, in particular to a photoelectrocatalyst, a preparation method thereof, an electrode and application. The chemical formula of the photoelectric catalyst is Cu Zn Sn < c > S < d > O < e >, wherein the ratio of a to b to c to d to e is (400 to 500) to (80 to 100) to (10 to 20) to (300 to 400) to (70 to 100). Therefore, the photoelectric catalyst provided by the invention can significantly enhance the adsorption performance on carbon dioxide (CO2), effectively reduce the energy barrier of CO2 activation, and promote the proceeding of a carbon-carbon (C-C) coupling reaction, thereby greatly improving the efficiency of a photoelectric catalytic reaction. In addition, when the photoelectric catalyst is used for catalyzing the CO2 reduction reaction, an aromatic alcohol oxidation reaction of an anode can be promoted, so that the conversion rate of aromatic alcohol is increased, and aromatic acid with high additional value is generated.

Description

Technical Field

[0001] This invention relates to the field of photoelectrocatalysis for CO2, specifically, to a photoelectrocatalyst, its preparation method, electrode, uses, and a method for catalyzing CO2 reduction coupled with aromatic alcohol oxidation. Background Technology

[0002] Existing CO2 utilization technologies mainly include CO2 mineralization, enzyme catalysis, thermocatalysis, electrocatalysis, photocatalysis, and photoelectrocatalysis. However, each of these technologies has its limitations. CO2 mineralization and storage pose potential risks such as disrupting ecological balance, CO2 leakage, and damage to saline aquifers; enzyme catalysis faces challenges such as demanding reaction conditions and slow reaction rates; due to CO2's thermodynamic and kinetic inertness, it is difficult to activate, and thermocatalytic conversion often requires harsh conditions of high temperature and high pressure; furthermore, CO2 reduction involves complex multi-proton electron transfer processes, with complex reaction mechanisms and numerous reaction pathways, resulting in poor product selectivity; photocatalytic conversion is limited by low solar energy utilization efficiency and low photogenerated carrier separation efficiency; and electrocatalytic conversion faces the challenge of requiring high overpotentials.

[0003] In contrast, photoelectrocatalysis combines the advantages of photocatalysis and electrocatalysis. By absorbing sunlight as an additional energy input, it effectively lowers the reaction energy barrier and improves the separation efficiency of photogenerated carriers, achieving a synergistic effect of photocatalysis and electrocatalysis. This allows CO2 molecules to be converted into high-value-added chemicals, making it a highly promising green and mild conversion technology. However, the main factors restricting the development of photoelectrocatalytic CO2 reduction technology include low conversion efficiency, poor product selectivity, and slow reaction rates due to insufficient current density of semiconductor catalysts. Therefore, developing novel and efficient photoelectrocatalysts to achieve highly selective reduction and conversion of CO2 into chemical products has become a major challenge in the current research field.

[0004] Aromatic acids are important precursors for pharmaceuticals, agrochemicals, and dyes. The selective oxidation of aromatic alcohols to synthesize aromatic acids is a crucial aspect of organic chemistry research. Conventional routes for synthesizing aromatic acids from aromatic alcohols require homogeneous catalysts or multiple reaction steps, such as strong oxidants like NaClO or KMnO4; while heterogeneous catalysts, to achieve high conversion rates and selectivity, typically require precious metals and high-pressure O2. Researching mild and environmentally friendly methods to directly convert aromatic alcohols into aromatic acids is crucial for improving energy efficiency and reducing the use of harmful substances. Utilizing photoelectrocatalysis to achieve the selective oxidation of aromatic alcohols under mild conditions is a green and mild strategy for preparing aromatic acids.

[0005] Based on this, the development of efficient photoelectrocatalysts to simultaneously achieve highly selective CO2 reduction and aromatic alcohol oxidation using photoelectrocatalysis technology, generating high-value-added carbon-based fuels and aromatic acids, has significant research and practical value. Summary of the Invention

[0006] This invention aims to at least partially solve at least one of the technical problems existing in the prior art. Therefore, this invention proposes a photoelectrocatalyst with high activity and high C2 product selectivity, which can promote anodic oxidation with high aromatic alcohol conversion and high aromatic acid selectivity, as well as its preparation method and application.

[0007] In a first aspect, the present invention provides a photocatalyst. According to an embodiment of the invention, the photocatalyst has the chemical formula Cu. a Zn b Sn c S d O e Wherein, a:b:c:d:e is (400-500):(80-100):(10-20):(300-400):(70-100). In this invention, the inventors discovered through extensive experimental research that by employing a specific preparation method, namely, using copper-zinc composite oxide to induce recrystallization of a copper-zinc-tin-sulfur substrate, zinc-tin composite oxide nanocubic particles can be grown in situ on the substrate. The photoelectrocatalyst prepared by this method can significantly enhance the adsorption performance of carbon dioxide (CO2), effectively reduce the energy barrier for CO2 activation, and promote carbon-carbon (CC) coupling reactions, thereby greatly improving the efficiency of photoelectrocatalytic reactions. In addition, while using this photoelectrocatalyst to catalyze the CO2 reduction reaction, it can also promote the oxidation reaction of aromatic alcohols at the anode, thereby increasing the conversion rate of aromatic alcohols and generating high-value-added aromatic acids.

[0008] In a second aspect, the present invention provides a method for preparing the photoelectrocatalyst described in the first aspect. According to an embodiment of the present invention, the method includes: first mixing a copper salt, a zinc salt, a complexing agent, and water to obtain a first mixture; evaporating the first mixture to obtain a wet gel; foaming and calcining the wet gel to obtain a precursor; second mixing the precursor, a copper source, a zinc source, a tin source, a sulfur source, a surfactant, and a hydrothermal solvent to obtain a second mixture; and reacting the second mixture to obtain the photoelectrocatalyst. Thus, by using the method of the present invention, a photoelectrocatalyst with high activity, high C2 product selectivity, and high aromatic alcohol conversion and high aromatic acid selectivity for promoting anodic oxidation of CO2 reduction can be prepared. By in-situ growing zinc-tin composite oxide nanocubic particles on a copper-zinc-tin-sulfur substrate through recrystallization induced by copper-zinc composite oxide, the adsorption performance for carbon dioxide (CO2) can be significantly enhanced, the energy barrier for CO2 activation can be effectively reduced, and carbon-carbon (CC) coupling reactions can be promoted, thereby significantly improving the efficiency of the photoelectrocatalytic reaction. At the same time, it can also promote the oxidation reaction of aromatic alcohols at the anode, improve the conversion rate of aromatic alcohols, and generate high-value-added aromatic acids.

[0009] In a third aspect, the present invention provides an electrode. According to embodiments of the present invention, the electrode comprises the photocatalyst described in the first aspect or a photocatalyst prepared using the method described in the second aspect. As described above, the photocatalyst of the present invention has high activity and high C2 product selectivity, and can promote anodic oxidation with high aromatic alcohol conversion rate and high aromatic acid selectivity. Thus, the electrode of the present invention can, on the one hand, improve the adsorption capacity for CO2 molecules and lower the energy barrier for CO2 activation, thereby accelerating the reaction and promoting the C-C coupling reaction; on the other hand, it can also promote the aromatic alcohol oxidation reaction in the anode, converting aromatic alcohols into high-value-added aromatic acids.

[0010] In a fourth aspect, the present invention proposes that the photocatalyst described in the first aspect, the photocatalyst prepared by the method described in the second aspect, or the electrode described in the third aspect have at least one of the following uses: catalytic CO2 reduction, catalytic CO2 reduction coupled with aromatic alcohol oxidation, and hydrogen production by water electrolysis. As described above, the photocatalyst of the present invention exhibits high activity and high C2 product selectivity, while simultaneously promoting anodic oxidation with high aromatic alcohol conversion and high aromatic acid selectivity. Therefore, the photocatalyst of the present invention not only performs excellently in CO2 reduction but also promotes the aromatic alcohol oxidation reaction in the anode, converting aromatic alcohols into aromatic acids.

[0011] In a fifth aspect, the present invention provides a method for catalytic CO2 reduction coupled with aromatic alcohol oxidation. According to an embodiment of the present invention, the method includes: using the electrode described in the third aspect as the working electrode, using a solvent containing aromatic alcohol, CO2, and a supporting electrolyte as the electrolyte, providing a counter electrode and a reference electrode, and performing a photoelectrocatalytic reaction. As described above, the photoelectrocatalyst of the present invention exhibits high activity and high C2 product selectivity, while also promoting anodic oxidation with high aromatic alcohol conversion and high aromatic acid selectivity. Therefore, the inventors have innovatively developed a CO2 reduction coupled with aromatic alcohol oxidation reaction system. Under this reaction system, the photoelectrocatalyst of the present invention can not only promote CO2 reduction but also improve the aromatic alcohol conversion rate in the system, generating high-value-added aromatic acids.

[0012] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0013] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0014] Figure 1 This is an experimental flowchart for preparing photoelectrocatalysts according to an embodiment of the present invention;

[0015] Figure 2 This is a CZTSO scanning electron microscope and its elemental surface scan results according to an embodiment of the present invention;

[0016] Figure 3 This is a transmission electron microscope (TEM) image of CZTSO diffraction spots and their morphology according to an embodiment of the present invention.

[0017] Figure 4 The graph shows the results of specific surface area measurement of CZTSO, CZO, and CZTS according to an embodiment of the present invention.

[0018] Figure 5 The graph shows the pore size and pore volume measurement results of CZTSO, CZO, and CZTS according to an embodiment of the present invention. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below, and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] For the sake of brevity, this article only discloses some specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0023] In this document, the terms “comprising” or “including” are open-ended expressions, meaning that they include the contents specified in this invention, but do not exclude other aspects.

[0024] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] The widespread use of fossil fuels has caused numerous environmental problems, particularly increasing CO2 emissions. Therefore, the recovery and conversion of CO2 into economically valuable hydrocarbons has attracted widespread attention. Besides traditional thermochemical cycling methods, photoelectrochemical (PEC) systems are considered a promising approach for solving the problem of efficient CO2 conversion. However, due to the thermodynamic and kinetic stability of CO2 molecules, it is difficult to convert CO2 into multi-electron transfer products. Therefore, developing efficient photoelectrochemical catalysts to reduce CO2 to liquid chemicals with high selectivity and yield has become a research hotspot. In recent years, many scholars have focused on improving key catalysts for the electrochemical reduction of CO2. Among them, transition metal sulfides have attracted considerable attention due to their complex valence states, excellent electrochemical performance, and high chemical stability, making them suitable as efficient catalysts for CO2 reduction. However, the low catalytic efficiency and low conductivity of transition metal sulfides hinder their industrialization.

[0026] In view of this, the inventors developed a novel photoelectrocatalyst, which utilizes a copper-zinc composite oxide to induce recrystallization of a copper-zinc-tin-sulfur substrate, thereby growing zinc-tin composite oxide nanocubic particles in situ on the substrate. The photoelectrocatalyst prepared using this method exhibits excellent performance, enhancing CO2 adsorption capacity, lowering the CO2 activation energy barrier, and promoting the formation of CO2 reduction products formic acid and acetic acid. Furthermore, during the experiment, to reduce the overpotential of the traditional anodic oxygen evolution reaction and generate higher-value aromatic acids to improve the system's economics, the inventors introduced aromatic alcohols. Unexpectedly, they discovered that this system can efficiently catalyze the oxidation reaction of aromatic alcohols, increasing the conversion rate of aromatic alcohols while simultaneously generating high-value aromatic acids. The photoelectrocatalyst, its preparation method, electrodes, and applications will be described in detail below.

[0027] Photocatalyst

[0028] In a first aspect, the present invention provides a photocatalyst. According to an embodiment of the invention, the photocatalyst has the chemical formula Cu. a Zn b Sn c S d O eWherein, a:b:c:d:e is (400-500):(80-100):(10-20):(300-400):(70-100). In this invention, the inventors discovered through extensive experimental research that by employing a specific preparation method, namely, using copper-zinc composite oxide to induce recrystallization of a copper-zinc-tin-sulfur substrate, zinc-tin composite oxide nanocubic particles can be grown in situ on the substrate. The photoelectrocatalyst prepared by this method can significantly enhance the adsorption performance of carbon dioxide (CO2), effectively reduce the energy barrier for CO2 activation, and promote carbon-carbon (CC) coupling reactions, thereby greatly improving the efficiency of photoelectrocatalytic reactions. In addition, while using this photoelectrocatalyst to catalyze the CO2 reduction reaction, it can also promote the oxidation reaction of aromatic alcohols at the anode, thereby increasing the conversion rate of aromatic alcohols and generating high-value-added aromatic acids.

[0029] For example, 'a' can be 400, 420, 450, 470, 500, etc.; 'b' can be 80, 85, 90, 95, 100, etc.; 'c' can be 10, 12, 15, 17, 20, etc.; 'd' can be 300, 320, 350, 370, 400, etc.; 'e' can be 70, 75, 80, 90, 100, etc.

[0030] In some embodiments of the present invention, the photocatalyst may further include at least one of the following additional technical features:

[0031] In some embodiments of the present invention, the weight ratio of Cu, Zn, Sn, S and O elements in the photocatalyst is Cu:Zn:Sn:S:O = (46-50):(6-10):(1-5):(32-36):(6-10).

[0032] For example, the weight parts of Cu are 46, 47, 48, 49, 50, etc.; the weight parts of Zn are 6, 7, 8, 9, 10, etc.; the weight parts of Sn are 1, 2, 3, 4, 5, etc.; the weight parts of S are 32, 33, 34, 35, 36, etc.; and the weight parts of O are 6, 7, 8, 9, 10, etc.

[0033] In some embodiments of the present invention, the photocatalyst is a nanoflower-like structure formed by the self-assembly of nanosheets, for example, a nanoflower with a particle size of 3.0-4.0 μm.

[0034] In some embodiments of the present invention, the specific surface area of ​​the photocatalyst is 12-36 m². 2 / g. For example, it can be 12m. 2 / g, 15m2 / g、18m 2 / g、20m 2 / g、22m 2 / g、25m 2 / g、28m 2 / g、30m 2 / g、32m 2 / g、35m 2 / g、36m 2 / g, etc., or can be any range of the above values. In some embodiments of the present invention, the specific surface area of ​​the photocatalyst is 18-24 m². 2 / g. In some embodiments of the present invention, the specific surface area of ​​the photocatalyst is 18-22 m². 2 / g. This provides more active sites, increases the adsorption area of ​​CO2 on the catalyst surface, and makes it more effectively activated, thereby accelerating the reaction.

[0035] In some embodiments of the present invention, the average pore size of the photocatalyst is 16-28 nm. For example, it can be 16 nm, 18 nm, 20 nm, 22 nm, 25 nm, 28 nm, etc., or any range of the above values. In some embodiments of the present invention, the average pore size of the photocatalyst is 18-24 nm. In some embodiments of the present invention, the average pore size of the photocatalyst is 18-22 nm. Therefore, CO2 can be effectively adsorbed, increasing its concentration on the catalyst surface, thereby accelerating the reaction; simultaneously, the light absorption efficiency of the catalyst can be improved, thereby generating more photogenerated carriers.

[0036] In some embodiments of the present invention, the pore volume of the photocatalyst is 0.08-0.10 m³. 3 / g. For example, it can be 0.08m. 3 / g, 0.09m 3 / g, 0.10m 3 / g, etc., or can be any range of the above values. Therefore, this pore volume means that the catalyst has a large number of pores, which can provide more adsorption sites, making it easier for reactant molecules (such as CO2) to adsorb onto the catalyst surface, thereby accelerating the reaction.

[0037] Methods for preparing photoelectrocatalysts

[0038] In a second aspect, the present invention provides a method for preparing the photocatalyst described in the first aspect. According to embodiments of the present invention, reference is made to... Figure 1 As shown, the method includes:

[0039] S100: First Mix

[0040] In this process, copper salt, zinc salt, complexing agent and water are first mixed to obtain a first mixture.

[0041] In some embodiments of the present invention, the molar ratio of Cu to Zn in the copper salt and zinc salt is 1:1.

[0042] In some embodiments of the present invention, the ratio of the molar amount of the complexing agent to the total molar amount of the metal elements in the first mixture is 1:(1-2). For example, it can be 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, etc., or it can be any range of the above values.

[0043] In some embodiments of the present invention, the molar concentration of the copper salt in the first mixture is 0.05-0.15 mol / L. For example, it can be 0.05 mol / L, 0.07 mol / L, 0.1 mol / L, 0.12 mol / L, 0.15 mol / L, etc., or it can be any range of the above values.

[0044] In some embodiments of the present invention, the molar concentration of the zinc salt in the first mixture is 0.05-0.15 mol / L. For example, it can be 0.05 mol / L, 0.07 mol / L, 0.1 mol / L, 0.12 mol / L, 0.15 mol / L, etc., or it can be any range of the above values.

[0045] In some embodiments of the present invention, the molar concentration of the complexing agent in the first mixture is 0.1-0.6 mol / L. For example, it can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, etc., or it can be any range of the above values.

[0046] This invention does not specifically limit the copper salt used; various soluble copper salts conventionally used in the art can be employed. Specific examples of the copper salt may include at least one of copper nitrate, copper chloride, copper alkoxide, and copper acetate. In some embodiments of this invention, the copper salt is copper nitrate.

[0047] This invention does not specifically limit the zinc salt used, and various soluble zinc salts conventionally used in the art can be employed. Specific examples of the zinc salt may include at least one of zinc nitrate, zinc chloride, zinc alkoxide, and zinc acetate. In some embodiments of this invention, the zinc salt is zinc nitrate.

[0048] In some embodiments of the present invention, the complexing agent includes at least one selected from maleic acid, glycine, and citric acid. In some embodiments of the present invention, the complexing agent is citric acid.

[0049] S200: Evaporation treatment

[0050] In this process, the first mixture obtained after the first mixing is evaporated to obtain a wet gel.

[0051] In some embodiments of the present invention, the evaporation temperature is 60-90°C. For example, it can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, or any range of the above values. In some embodiments of the present invention, the evaporation temperature is 75-85°C. In some embodiments of the present invention, the evaporation time is 2-5 hours. For example, it can be 2 hours, 3 hours, 4 hours, 5 hours, or any range of the above values. Thus, the water in the first mixture can be evaporated to obtain a wet gel.

[0052] S300: Foaming treatment

[0053] In this process, the wet gel obtained after the above evaporation treatment is foamed to obtain a solid sample.

[0054] In some embodiments of the present invention, the foaming treatment temperature is 160-200°C. For example, it can be 160°C, 170°C, 180°C, 190°C, 200°C, or any range of the above values. In some embodiments of the present invention, the foaming treatment temperature is 180-200°C. In some embodiments of the present invention, the foaming treatment time is 2-6 hours, for example, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, or any range of the above values. Therefore, the moisture in the wet gel can be completely evaporated, resulting in a dry solid sample.

[0055] In some embodiments of the present invention, before the solid sample obtained by foaming is subjected to the calcination treatment, the solid sample is further subjected to crushing and grinding treatment so as to achieve sufficient calcination during the calcination treatment.

[0056] S400: Calcination treatment

[0057] In this process, the solid sample after the above foaming treatment is calcined to obtain the precursor.

[0058] In some embodiments of the present invention, the calcination temperature is 500-850°C. For example, it can be 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, etc., or any range of the above values. In some embodiments of the present invention, the calcination temperature is 550-750°C. In some embodiments of the present invention, the calcination time is 3-6 hours, for example, 3 hours, 4 hours, 5 hours, 6 hours, etc., or any range of the above values. Therefore, the solid sample can be fully calcined to obtain the precursor.

[0059] In some embodiments of the present invention, the precursor obtained after calcination is ground to reduce the particle size of the precursor to less than 48 μm. This promotes contact between the reactants and the catalyst, increases the number of active sites, reduces photogenerated carrier recombination, and improves diffusion mass transfer efficiency.

[0060] S500: Second Hybrid

[0061] In this process, the precursor, copper source, zinc source, tin source, sulfur source, surfactant and hydrothermal solvent are mixed for the second time to obtain a second mixture.

[0062] In some embodiments of the present invention, the molar ratio of Cu in the copper source, Zn in the zinc source, Sn in the tin source, and S in the sulfur source is (1-3):1:1:(4-6). For example, it can be 1:1:1:4, 1:1:1:5, 2:1:1:6, 2:1:1:5, 3:1:1:5, etc., or it can be any range of the above values.

[0063] In some embodiments of the present invention, the molar amount of Cu in the precursor is the same as the molar amount of Cu in the copper source.

[0064] In some embodiments of the present invention, the molar concentration of the copper source in the second mixture is 0.015-0.045 mol / L. For example, it can be 0.015 mol / L, 0.025 mol / L, 0.035 mol / L, 0.045 mol / L, or any range of the above values.

[0065] In some embodiments of the present invention, the molar concentration of the zinc source in the second mixture is 0.015-0.03 mol / L. For example, it can be 0.015 mol / L, 0.017 mol / L, 0.02 mol / L, 0.023 mol / L, 0.025 mol / L, 0.027 mol / L, 0.23 mol / L, or any range of the above values.

[0066] In some embodiments of the present invention, the molar concentration of the tin source in the second mixture is 0.015-0.03 mol / L. For example, it can be 0.015 mol / L, 0.017 mol / L, 0.02 mol / L, 0.023 mol / L, 0.025 mol / L, 0.027 mol / L, 0.23 mol / L, or any range of the above values.

[0067] In some embodiments of the present invention, the molar concentration of the sulfur source in the second mixture is 0.06-0.09 mol / L. For example, it can be 0.06 mol / L, 0.07 mol / L, 0.08 mol / L, 0.09 mol / L, or any range of the above values.

[0068] In some embodiments of the present invention, the molar concentration of the surfactant in the second mixture is 0.2-0.4 μmol / L. For example, it can be 0.2 μmol / L, 0.24 μmol / L, 0.28 μmol / L, 0.3 μmol / L, 0.34 μmol / L, 0.38 μmol / L, 0.4 μmol / L, or any range of the above values.

[0069] In some embodiments of the present invention, the molar concentration of the precursor in the second mixture is 0.015-0.045 mol / L. For example, it can be 0.015 μmol / L, 0.025 mol / L, 0.035 mol / L, 0.045 mol / L, or any range of the above values.

[0070] The present invention does not particularly limit the copper source, and various soluble copper salts conventionally used in the art can be employed. Specific examples of the copper salt may include at least one of other salts or hydrated salts such as copper nitrate, copper chloride, copper sulfate, copper acetate, and copper chloride dihydrate. In some embodiments of the present invention, the copper source is copper chloride.

[0071] The present invention does not particularly limit the zinc source, and various soluble zinc salts conventionally used in the art can be employed. Specific examples of the zinc salt may include at least one of zinc nitrate, zinc chloride, zinc sulfate, and zinc acetate. In some embodiments of the present invention, the zinc source is zinc chloride.

[0072] The present invention does not particularly limit the tin source, and various soluble tin salts conventionally used in the art can be used. Specific examples of the tin salt may include at least one of other salts or hydrated salts such as tin nitrate, tin chloride, tin sulfate, tin acetate, and tin chloride pentahydrate. In some embodiments of the present invention, the tin source is tin chloride.

[0073] The present invention does not particularly limit the sulfur source, and various soluble organic sulfur sources conventionally used in the art can be used. Specific examples of the sulfur source may include at least one of L-cysteine ​​and thiourea. In some embodiments of the present invention, the sulfur source is thiourea.

[0074] In some embodiments of the present invention, the surfactant includes at least one selected from polyvinylpyrrolidone, polyethylene glycol 400, and emulsifier OP-10. In some embodiments of the present invention, the surfactant is polyvinylpyrrolidone.

[0075] In some embodiments of the present invention, the hydrothermal solvent includes at least one of ethylene glycol and pure water. In some embodiments of the present invention, the hydrothermal solvent is ethylene glycol. The amount of ethylene glycol used is related to the hydrothermal reactor used, and generally does not exceed 75% of the reactor's capacity (otherwise, the high-temperature, high-pressure hydrothermal reactor poses a safety hazard of explosion). For example, if a 50ml hydrothermal reactor is used in the experiment, the amount of ethylene glycol used is approximately 35ml.

[0076] S500: Reaction Processing

[0077] In this process, the second mixture obtained after the second mixing is subjected to reaction treatment to obtain the photoelectrocatalyst.

[0078] In some embodiments of the present invention, the reaction temperature is 180-240°C, for example, it can be 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, etc., or any range of the above values. In some embodiments of the present invention, the reaction time is 10-24 hours, for example, it can be 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours, 24 hours, etc., or any range of the above values. Therefore, the reaction can proceed sufficiently to generate the photoelectrocatalyst described in the present invention.

[0079] In some embodiments of the present invention, after the reaction treatment, the process further includes washing and drying the reaction product to obtain the photoelectrocatalyst.

[0080] In some embodiments of the present invention, the washing process is carried out using at least one of deionized water and ethanol.

[0081] In some embodiments of the present invention, the drying temperature is 50-70°C. For example, it can be 50°C, 55°C, 60°C, 65°C, 70°C, or any range of the above values. In some embodiments of the present invention, the drying time is 10-14 hours. For example, it can be 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, or any range of the above values.

[0082] Therefore, by employing the method described in this invention, a photoelectrocatalytic CO2 reduction catalyst with high activity and high C2 product selectivity can be prepared, while simultaneously promoting anodic oxidation with high aromatic alcohol conversion and high aromatic acid selectivity. In-situ growth of zinc-tin composite oxide nanocubic particles on a copper-zinc-tin-sulfur substrate via recrystallization induced by copper-zinc composite oxide significantly enhances the adsorption performance for carbon dioxide (CO2), effectively lowers the energy barrier for CO2 activation, and promotes carbon-carbon (CC) coupling reactions, thereby greatly improving the efficiency of the photoelectrocatalytic reaction. Simultaneously, it also promotes the aromatic alcohol oxidation reaction at the anolyse, increasing the conversion rate of aromatic alcohols and generating high-value-added aromatic acids.

[0083] electrode

[0084] In a third aspect, the present invention provides an electrode. According to embodiments of the present invention, the electrode comprises the photocatalyst described in the first aspect or a photocatalyst prepared using the method described in the second aspect. As described above, the photocatalyst of the present invention has high activity and high C2 product selectivity, and can promote anodic oxidation with high aromatic alcohol conversion rate and high aromatic acid selectivity. Thus, the electrode of the present invention can, on the one hand, improve the adsorption capacity for CO2 molecules and lower the energy barrier for CO2 activation, thereby accelerating the reaction and promoting the C-C coupling reaction; on the other hand, it can also promote the aromatic alcohol oxidation reaction in the anode, converting aromatic alcohols into high-value-added aromatic acids.

[0085] use

[0086] In a fourth aspect, the present invention proposes that the photocatalyst described in the first aspect, the photocatalyst prepared by the method described in the second aspect, or the electrode described in the third aspect have at least one of the following uses: catalytic CO2 reduction, catalytic CO2 reduction coupled with aromatic alcohol oxidation, and hydrogen production by water electrolysis. As described above, the photocatalyst of the present invention exhibits high activity and high C2 product selectivity, while simultaneously promoting anodic oxidation with high aromatic alcohol conversion and high aromatic acid selectivity. Therefore, the photocatalyst of the present invention not only performs excellently in CO2 reduction but also promotes the aromatic alcohol oxidation reaction in the anode, converting aromatic alcohols into aromatic acids.

[0087] A method for catalytic CO2 reduction coupled with aromatic alcohol oxidation

[0088] In a fifth aspect, the present invention provides a method for catalytic CO2 reduction coupled with aromatic alcohol oxidation. According to an embodiment of the present invention, the method includes: using the electrode described in the third aspect as the working electrode, using a solvent containing aromatic alcohol, CO2, and a supporting electrolyte as the electrolyte, providing a counter electrode and a reference electrode, and performing a photoelectrocatalytic reaction. As described above, the photoelectrocatalyst of the present invention exhibits high activity and high C2 product selectivity, while also promoting anodic oxidation with high aromatic alcohol conversion and high aromatic acid selectivity. Therefore, the inventors have innovatively developed a CO2 reduction coupled with aromatic alcohol oxidation reaction system. Under this reaction system, the photoelectrocatalyst of the present invention can not only promote CO2 reduction but also improve the aromatic alcohol conversion rate in the system, generating high-value-added aromatic acids.

[0089] In some embodiments of the present invention, the solvent includes at least one selected from water, acetonitrile, dimethyl sulfoxide, dimethylformamide, acetone, sulfolane, ethylene glycol dimethyl ether, tetrahydrofuran, and propylene carbonate. In some embodiments of the present invention, the solvent is a mixture of water and acetonitrile. In some embodiments of the present invention, the volume ratio of water to acetonitrile is 1:(0.2-5), for example, it can be 1:0.2, 1:1, 1:2, 1:3, 1:4, 1:5, etc., or it can be any range of the above values.

[0090] In some embodiments of the present invention, the supporting electrolyte includes at least one selected from KHCO3, NaHCO3, CsHCO3, Na2SO4, KNO3, tetrabutylammonium perchlorate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium trifluoromethanesulfonate, tetrabutylammonium perchlorate, tetrabutylammonium tetrafluoroborate, and tetrabutylammonium bromide. In some embodiments of the present invention, the supporting electrolyte includes KHCO3. In some embodiments of the present invention, the molar concentration of KHCO3 in the electrolyte is 0.05-0.15M, for example, it can be 0.05M, 0.07M, 0.1M, 0.12M, 0.15M, etc.

[0091] In some embodiments of the present invention, the counter electrode includes at least one selected from Pt electrode, graphite rod electrode, Ag electrode, Ni electrode, W electrode, Pb electrode, and Cu electrode. In some embodiments of the present invention, the counter electrode is a Pt electrode.

[0092] In some embodiments of the present invention, the reference electrode is an Ag / AgCl electrode, Ag / Ag + The reference electrode is at least one of the following: an electrode, a saturated calomel electrode, a Hg / Hg₂SO₄ electrode, and a Hg / HgO electrode. In some embodiments of the present invention, the reference electrode is an Ag / AgCl electrode.

[0093] In some embodiments of the present invention, the concentration of the aromatic alcohol in the electrolyte is 5-25 mM. For example, it can be 5 mM, 10 mM, 15 mM, 20 mM, 25 mM, etc., or any range of the above values. This improves the selectivity of acetic acid (a CO2 reduction product) and aromatic acid (an aromatic alcohol oxide), thereby increasing the yield of acetic acid and aromatic acids.

[0094] In some embodiments of the present invention, the water content in the electrolyte is 16.7-83.3%. For example, it can be 16.7%, 20%, 30%, 40%, 50%, 60%, 70%, 83.3%, etc., or any range of the above values. This improves the selectivity of acetic acid (a CO2 reduction product) and aromatic acid (an aromatic alcohol oxide), thereby increasing the yield of acetic acid and aromatic acids.

[0095] In some embodiments of the present invention, the photoelectrocatalytic reaction is carried out under conditions where a power supply is provided by an external circuit. In some embodiments of the present invention, the reference electrode is an Ag / AgCl electrode, and the potential range of the power supply is -0.8V to -1.8V vs. Ag / AgCl. For example, it can be -0.8V vs. Ag / AgCl, -1V vs. Ag / AgCl, -1.3V vs. Ag / AgCl, -1.5V vs. Ag / AgCl, -1.8V vs. Ag / AgCl, etc., or any range of the above values. Therefore, the selectivity of acetic acid (a CO2 reduction product) and aromatic acid (an aromatic alcohol oxide) can be improved, thereby increasing the yield of acetic acid and aromatic acids.

[0096] It should be noted that the photoelectrocatalytic CO2 reduction conditions can be carried out using conventional methods in the field, such as using CO2 at any flow rate, a reaction temperature of 10–50 °C, and a pressure of 0.5–2.5 bar.

[0097] The embodiments of the present invention are described in detail below. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0098] The flow rate of CO2 feed into the reactor for photoelectrocatalytic CO2 reduction was measured at the feed inlet, and the H2, O2, and possible CO2 reduction gas products in the effluent were measured and analyzed at the reactor outlet. The content of aromatic alcohols, aromatic aldehydes, and aromatic acids, as well as possible CO2 reduction liquid products such as formic acid and acetic acid, in the electrolyte after the reaction were measured and analyzed. The conversion rate (%) of aromatic alcohols, the selectivity (%) of aromatic acids, and the selectivity (%) of acetic acid were calculated using the following formulas:

[0099] Aromatic alcohol conversion rate % = [(Aromatic aldehyde concentration in discharge + Aromatic acid concentration in discharge) / Aromatic alcohol concentration in feed] × 100%;

[0100] Aromatic acid selectivity % = [Aromatic acid concentration in discharge / (Aromatic aldehyde concentration in discharge + Aromatic acid concentration in discharge)] × 100%;

[0101] Acetic acid selectivity % = [(number of moles of product × number of electrons transferred during the formation of acetic acid × Faraday constant) / current density × time] × 100%; where the number of electrons transferred during the formation of acetic acid is 8, and the Faraday constant is 96485 C / mol.

[0102] Example 1: Fabrication of CZTSO photocathode

[0103] 1. Preparation of CZO precursor

[0104] (1) Mix copper nitrate, zinc nitrate and citric acid (the molar ratio of Cu-Zn elements in the material is 1:1), and the molar amount of citric acid added is 1.3 times the total molar amount of all metal atoms;

[0105] (2) Add deionized water to prepare a solution, ensuring that the concentration of copper nitrate solution in the mixed solution is 0.10 mol / L;

[0106] (3) Stir the solution prepared in step (2) at room temperature for 30 minutes;

[0107] (4) Stir the solution from step (3) at 80°C for 3 hours to obtain a wet gel;

[0108] (5) Place the wet gel obtained in step (4) in a drying oven, foam it at a temperature range of 180°C and dry it for 5 hours, and then crush and grind the obtained solid sample.

[0109] (6) Place the sample ground in step (5) into a muffle furnace and calcine it at 550°C in air atmosphere for 4 hours. The heating rate is kept at 2.0°C / min. Grind the calcined solid powder until the particle size is less than 48μm to finally obtain CuO-ZnO sample (marked as CZO precursor).

[0110] 2. Preparation of CZTSO Samples

[0111] (1) Mix copper salt (copper chloride), zinc salt (zinc chloride), tin salt (tin chloride), thiourea and surfactant polyvinylpyrrolidone (in the material, the molar ratio of Cu-Zn-Sn-S elements is 2:1:1:5, and the molar ratio of copper salt to surfactant is 75:1);

[0112] (2) Add ethylene glycol to prepare a solution and stir at room temperature for 30 min;

[0113] (3) Add the CZO precursor prepared above to the solution obtained in step (2), wherein the number of moles of Cu element is consistent with that in (1);

[0114] (4) Stir the solution obtained in step (3) at room temperature for 1 hour;

[0115] (5) Transfer the solution obtained in step (4) to a polytetrafluoroethylene reactor and keep it at 200°C for 12 hours;

[0116] (6) After the reactor is naturally cooled to room temperature, the product is washed with deionized water and ethanol and dried at 60°C for 6 hours to obtain CuZnSnSO sample (labeled as CZTSO).

[0117] 3. Preparation of CZTSO catalyst as cathode electrode

[0118] (1) Add 4 mg of CZTSO catalyst to a mixed solution of 10 μL Nafion solution, 37.5 μL ethanol and 52.5 μL water;

[0119] (2) The solution obtained in (1) was sonicated at 40°C for 1 hour;

[0120] (3) The solution obtained in (2) is dropped onto a 1cm×1.5cm carbon paper, and the solution is added in two drops, each time 50μL. After drying, the next drop is added. After drying, CZTSO photocathode is obtained.

[0121] Example 2: Appearance characterization of CZTSO catalyst

[0122] The surface morphology of the catalyst was obtained by scanning electron microscopy, and the elemental distribution was obtained by surface scanning. The diffraction patterns of the catalyst were obtained by transmission electron microscopy, and its crystal structure was analyzed.

[0123] Scanning electron microscopy and its elemental surface scan results are shown in Figure 2 As shown, this CZTSO exhibits a self-assembled nanoflower-like structure composed of nanosheets, containing Zn, Sn, Cu, S, and O elements. Furthermore, the nanocubes on its surface are enriched with Zn, Sn, and O elements.

[0124] The results of transmission electron microscopy diffraction spots and their morphology are shown in Figure 3 As shown, the presence of surface nanocubes is further confirmed. Secondly, the diffraction spots match the CZTS crystal form, proving that the catalyst substrate is CZTS.

[0125] Example 3: CZTSO photoelectrocatalytic CO2 reduction coupled with aromatic alcohol oxidation

[0126] 1. Dissolve p-nitrobenzyl alcohol and KHCO3 in a mixed solution of acetonitrile and pure water in a volume ratio of 1:1, ensuring that their concentrations are 5 mM and 0.1 M, respectively;

[0127] 2. Pass Ar into the mixed solution obtained in step 1 for 30 minutes to purge the dissolved gas in the solution;

[0128] 3. Pass CO2 into the mixed solution obtained in step 2 for 30 minutes to saturate it with CO2, and obtain the mixed solution.

[0129] 4. A single-chamber stainless steel photoelectrochemical reactor was used. The CZTSO photocathode prepared in Example 1 was used as the working electrode. Pt sheet and Ag / AgCl electrode were used as the counter electrode and reference electrode, respectively. The working electrode of the cathode was irradiated with a xenon lamp to simulate sunlight. The counter electrode and the working electrode were connected to form an external circuit through an electrochemical workstation. The mixed solution obtained in step 3 was used as the electrolyte. 5 mmol / L of aromatic alcohol was added, and the photoelectrochemical CO2 reduction coupled with aromatic alcohol oxidation reaction was carried out at a potential of -1V vs. Ag / AgCl.

[0130] Experiments were conducted using different aromatic alcohols, and the results are shown in Table 1. This system demonstrates beneficial effects on aromatic alcohols with different functional group types, substituent positions, and carbon chain lengths, while maintaining an aromatic acid selectivity of over 80%. While maintaining good aromatic alcohol conversion and aromatic acid selectivity, the cathode using this photoelectrocatalyst can effectively reduce CO2 with high yields of acetic acid and formic acid.

[0131] Table 1

[0132]

[0133]

[0134] Comparative Example 1

[0135] 1. Preparation of CZO samples

[0136] (1) Mix copper nitrate, zinc nitrate and citric acid (the molar ratio of Cu-Zn elements in the material is 1:1), and the molar amount of citric acid added is 1.3 times the total molar amount of all metal atoms;

[0137] (2) Add deionized water to prepare a solution, ensuring that the concentration of copper nitrate solution in the mixed solution is 0.10 mol / L;

[0138] (3) Stir the solution prepared in step (2) at room temperature for 30 minutes;

[0139] (4) Stir the solution from step (3) at 80°C for 3 hours to obtain a wet gel;

[0140] (5) Place the wet gel obtained in step (4) in a drying oven, foam it at a temperature range of 180°C and dry it for 5 hours, and then crush and grind the obtained solid sample.

[0141] (6) Place the sample ground in step (5) into a muffle furnace and calcine it at 550°C in air atmosphere for 4 hours. The heating rate is kept at 2.0°C / min. Grind the calcined solid powder until the particle size is less than 48μm to finally obtain CuO-ZnO sample (marked as CZO). Grind the catalyst until the particle size is no greater than 48μm.

[0142] 2. Preparation of CZO catalyst as cathode electrode

[0143] (1) Add 4 mg of CZO sample to a mixed solution of 10 μL Nafion solution, 37.5 μL ethanol and 52.5 μL water;

[0144] (2) The solution obtained in (1) was sonicated at 40°C for 1 hour;

[0145] (3) The solution obtained in (2) is dropped onto a 1cm×1.5cm carbon paper, and the solution is added in two separate drops, each drop being 50μL. After drying, the next drop is added. After drying, a CZO photocathode is obtained.

[0146] Comparative Example 2

[0147] 1. Preparation of CZTS Samples

[0148] (1) Mix copper salt (copper chloride), zinc salt (zinc chloride), tin salt (tin chloride), thiourea and surfactant polyvinylpyrrolidone (in the material, the molar ratio of Cu-Zn-Sn-S elements is 2:1:1:5, and the molar ratio of copper salt to surfactant is 75:1);

[0149] (2) Add ethylene glycol to prepare a solution and stir at room temperature for 30 min;

[0150] (3) Transfer the solution obtained in (2) to a polytetrafluoroethylene reactor and keep it at 200°C for 12 hours;

[0151] (4) After the reaction vessel is naturally cooled to room temperature, the product is washed with deionized water and ethanol and dried at 60°C for 6 hours to obtain CuZnSnS sample (labeled as CZTS).

[0152] 2. Preparation of CZTS catalyst as cathode electrode

[0153] (1) Add 4 mg of CZTS catalyst to a mixed solution of 10 μL Nafion solution, 37.5 μL ethanol and 52.5 μL water;

[0154] (2) The solution obtained in (1) was sonicated at 40°C for 1 hour;

[0155] (3) The solution obtained in (2) is dropped onto a 1cm×1.5cm carbon paper, and the solution is added in two drops, each time 50μL. After drying, the next drop is added. After drying, CZTSO photocathode is obtained.

[0156] Performance testing:

[0157] 1. The specific surface area, pore size, and pore volume of the CZTSO sample prepared in Example 1, the CZO sample prepared in Comparative Example 1, and the CZTS sample prepared in Comparative Example 2 were measured. The specific surface area, pore size, and pore volume were all obtained by the BET method.

[0158] The specific surface area measurements of the three are shown below. Figure 4 As shown, the results indicate that CZTS, CZTSO, and CZO catalysts possess good gas adsorption capabilities, and their pore structure is a mixed microporous and mesoporous planar slit structure, consistent with the morphological results obtained from scanning electron microscopy and transmission electron microscopy. The pore size and pore volume measurements of the three catalysts are shown in [Figure number missing]. Figure 5 As shown, the results indicate that the gas adsorption of CZTS and CZO catalysts is mainly characterized by macropores of about 50 nm, while the CZTSO catalyst is mainly characterized by micropores of less than 2 nm and mesopores between 2 and 50 nm.

[0159] 2. The CZTSO photocathode prepared in Example 1, the CZO photocathode prepared in Comparative Example 1, and the CZO photocathode prepared in Comparative Example 2 were used as working electrodes for electrocatalytic CO2 reduction coupled with aromatic alcohol oxidation. The specific reaction process is as follows:

[0160] 1) Dissolve p-nitrobenzyl alcohol and KHCO3 in a mixed solution of 15 ml acetonitrile and 15 ml pure water, ensuring that their concentrations are 5 mM and 0.1 M, respectively;

[0161] 2) Pass Ar into the mixed solution obtained in step 1 for 30 minutes to purge the dissolved gas in the solution;

[0162] 3) Pass CO2 into the mixed solution obtained in step 2 for 30 minutes to saturate it with CO2, and obtain the mixed solution;

[0163] 4) A single-chamber stainless steel photoelectrochemical reactor was used. The CZTSO photocathode prepared in Example 1, the CZO photocathode prepared in Comparative Example 1, and the CZO photocathode prepared in Comparative Example 2 were used as working electrodes, respectively. Pt sheet and Ag / AgCl electrode were used as counter electrode and reference electrode, respectively. Xenon lamp was used to simulate sunlight to irradiate the working electrode of the cathode. The counter electrode and the working electrode were connected to form an external circuit through an electrochemical workstation. The mixed solution obtained in step 3 was used as the electrolyte. 4-Nitrobenzyl alcohol was added, wherein the concentration of 4-nitrobenzyl alcohol in the electrolyte was 5 mmol / L. The photoelectrochemical CO2 reduction coupled with aromatic alcohol oxidation reaction was carried out under the condition of potential of -1V vs. Ag / AgCl.

[0164] The experimental results are shown in Table 2. Compared with the precursor CZO and the comparative CZTS, the CZTSO catalyst significantly improved the selectivity of acetic acid and the yield of formic acid and acetic acid. At the same time, the system also significantly improved the conversion rate of aromatic alcohols and the selectivity of aromatic acids. This indicates that the CZTSO catalyst can serve as an excellent photoelectrocatalyst for catalyzing the CO2 reduction reaction and promoting the aromatic alcohol oxidation reaction at the anode.

[0165] Table 2

[0166]

[0167] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0168] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A photoelectrocatalyst, characterized in that, The chemical formula of the photocatalyst is Cu. a Zn b Sn c S d O e ; Where a:b:c:d:e is (400-500):(80-100):(10-20):(300-400):(70-100).

2. The photocatalyst according to claim 1, characterized in that, The specific surface area of ​​the photoelectrocatalyst is 12-36 m². 2 / g, preferably 18-24m 2 / g, more preferably 18-22m 2 / g; Optionally, the average pore size of the photocatalyst is 16-28 nm, preferably 18-24 nm, and more preferably 18-22 nm; Optionally, the pore volume of the photocatalyst is 0.08-0.10 m³. 3 / g.

3. A method for preparing the photocatalyst according to claim 1 or 2, characterized in that, include: The copper salt, zinc salt, complexing agent and water are mixed to obtain a first mixture; The first mixture was evaporated to obtain a wet gel; The wet gel was subjected to foaming and calcination to obtain a precursor. The precursor, copper source, zinc source, tin source, sulfur source, surfactant, and hydrothermal solvent are mixed in a second way to obtain a second mixture. The second mixture is subjected to a reaction treatment to obtain the photoelectrocatalyst.

4. The method according to claim 3, characterized in that, The molar ratio of Cu to Zn in the copper and zinc salts is 1:

1. Optionally, the ratio of the molar amount of the complexing agent to the total molar amount of the metal elements in the first mixture is 1:(1-2); Optionally, the molar concentration of the copper salt in the first mixture is 0.05-0.15 mol / L; Optionally, the molar concentration of the zinc salt in the first mixture is 0.05-0.15 mol / L; Optionally, the molar concentration of the complexing agent in the first mixture is 0.1-0.6 mol / L; Optionally, the molar ratio of Cu in the copper source, Zn in the zinc source, Sn in the tin source and S in the sulfur source is (1-3):1:1:(4-6); Optionally, the molar amount of Cu in the precursor is the same as the molar amount of Cu in the copper source; Optionally, the molar concentration of the copper source in the second mixture is 0.015-0.045 mol / L; Optionally, the molar concentration of the zinc source in the second mixture is 0.015-0.03 mol / L; Optionally, the molar concentration of the tin source in the second mixture is 0.015-0.03 mol / L; Optionally, the molar concentration of the sulfur source in the second mixture is 0.06-0.09 mol / L; Optionally, the molar concentration of the surfactant in the second mixture is 0.2-0.4 μmol / L; Optionally, the molar concentration of the precursor in the second mixture is 0.015-0.045 mol / L.

5. The method according to claim 4, characterized in that, The copper salt includes at least one of copper nitrate, copper chloride, copper alkoxide, and copper acetate, preferably copper nitrate; Optionally, the zinc salt includes at least one of zinc nitrate, zinc chloride, zinc alkoxide, and zinc acetate, preferably zinc nitrate; Optionally, the copper source includes at least one of copper nitrate, copper chloride, copper sulfate, and copper acetate, preferably copper chloride; Optionally, the zinc source includes at least one of zinc nitrate, zinc chloride, zinc sulfate, and zinc acetate, preferably zinc chloride; Optionally, the tin source includes at least one of tin nitrate, tin chloride, tin sulfate, and tin acetate, preferably tin chloride; Optionally, the sulfur source includes at least one of L-cysteine ​​and thiourea, preferably thiourea; Optionally, the complexing agent includes at least one of maleic acid, glycine, and citric acid, preferably citric acid; Optionally, the surfactant includes at least one of polyvinylpyrrolidone, polyethylene glycol 400, and emulsifier OP-10, preferably polyvinylpyrrolidone; Optionally, the hydrothermal solvent includes at least one of ethylene glycol and pure water; preferably ethylene glycol.

6. The method according to claim 3, characterized in that, The evaporation temperature is 60-90℃, preferably 75-85℃; optionally, the evaporation time is 2-5 hours. Optionally, the temperature of the foaming treatment is 160-200℃, preferably 180-200℃; optionally, the foaming treatment time is 2-6 hours. Optionally, the calcination temperature is 500-850℃, preferably 550-750℃; optionally, the calcination time is 3-6 hours. Optionally, the reaction temperature is 180-240℃, preferably 180-220℃; optionally, the reaction time is 10-24h.

7. An electrode, characterized in that, include: The photocatalyst according to claim 1 or 2, or the photocatalyst prepared by the method according to any one of claims 3-6.

8. The photocatalyst according to claim 1 or 2, the photocatalyst prepared by the method according to any one of claims 3-6, or the electrode according to claim 7 has at least one of the following uses: catalytic CO2 reduction, catalytic CO2 reduction coupled with aromatic alcohol oxidation, and hydrogen production by water electrolysis.

9. A method for catalytic CO2 reduction coupled with aromatic alcohol oxidation, characterized in that, include: Using the electrode described in claim 7 as the working electrode, and a solvent containing aromatic alcohol, CO2 and supporting electrolyte as the electrolyte, a counter electrode and a reference electrode are provided to carry out a photoelectrocatalytic reaction.

10. The method according to claim 9, characterized in that, The solvent includes at least one of water, acetonitrile, dimethyl sulfoxide, dimethylformamide, acetone, sulfolane, ethylene glycol dimethyl ether, tetrahydrofuran, and propylene carbonate; preferably a mixture of water and acetonitrile. Optionally, the supporting electrolyte includes at least one of KHCO3, NaHCO3, CsHCO3, Na2SO4, KNO3, tetrabutylammonium perchlorate, tetrabutylammonium tetrafluoroborate, tetrabutylammonium trifluoromethanesulfonate, tetrabutylammonium perchlorate, tetrabutylammonium tetrafluoroborate, and tetrabutylammonium bromide. Optionally, the counter electrode includes at least one of a Pt electrode, a graphite rod electrode, an Ag electrode, a Ni electrode, a W electrode, a Pb electrode, and a Cu electrode, preferably a Pt electrode; Optionally, the reference electrode is an Ag / AgCl electrode or an Ag / Ag electrode. + At least one of the following: electrode, saturated calomel electrode, Hg / Hg2SO4 electrode, and Hg / HgO electrode, preferably Ag / AgCl electrode; Optionally, the concentration of the aromatic alcohol in the electrolyte is 5-25 mM; Optionally, the water content in the electrolyte is 16.7-83.3%.

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