582 results about "Visible light irradiation" patented technology

The invention discloses a process for synthesizing ammonia by coupling low-temperature plasma with electro-catalysis in the field of clean energy and green chemical industry, which comprises the following specific steps: mixing air and water vapor, feeding the mixture into a dielectric barrier discharge reactor, filling the reactor with a multi-stage heterojunction gradient doped carbon coated catalyst, generating active gas containing NOx under pulse high voltage, and condensing and then entering an electrocatalytic reduction unit. And an electro-catalysis product enters a photo-thermal separation module integrated with a Janus type photo-thermal electrode, the temperature of the electrode is locally increased under visible light irradiation, NH3 desorption is promoted, and finally high-purity ammonia is obtained through polyimide membrane separation. The multistage heterojunction gradient-doped carbon-coated catalyst adopted in the process is prepared through multiple steps and contains gradient-doped boron, sulfur and Au nanoparticles on the surface, NOx adsorption, electron transport and sintering resistance are synergistically improved, and efficient ammonia synthesis under mild conditions is achieved.

This invention discloses a visible-light-responsive dynamically covalently cross-linked self-healing polyurethane and its preparation method, belonging to the field of self-healing materials technology. The material is prepared by reacting diisocyanate, long-chain diol, butanediol, trimethylolpropane, and a monool containing an azophenylboronic acid structure in a certain proportion at 60°C. This invention achieves visible-light-responsive self-healing of the polyurethane material by introducing a visible-light-responsive azophenylboronic acid structure into the polyurethane and utilizing the photoresponsive cis-trans isomerization of the azo structure to regulate the reversible breakage and recombination of the boron-oxygen hexacyclic ring. The visible-light-responsive dynamically covalently cross-linked self-healing polyurethane material prepared by this invention maintains high mechanical strength (16.47 MPa) while exhibiting a strength self-healing efficiency of 95.8% after 8 hours of visible light irradiation, showing broad application prospects in smart materials, anti-corrosion coatings, and other fields.

The invention relates to the technical field of transmission membranes, in particular to a transmission membrane based on dithienylethene and a preparation method of the transmission membrane. The transmission film comprises a base film and light-operated molecules, the base film is coated with the light-operated molecules, and the light-operated molecules have light response groups. A detection result shows that after ultraviolet irradiation, the transmission film can quickly realize complete conversion from an open loop to a closed loop; after visible light irradiation is recovered, the transmission film can efficiently and reversibly recover to an open-loop state. In addition, the transport membrane has a high on-off ratio to five ions of sodium, potassium, lithium, magnesium and calcium. The transmission membrane based on dithienylethene, which is prepared by taking terminal amino-modified dithienylethene as a basic unit, not only has abundant nano-channels, but also is endowed with the characteristic of regulating and controlling the opening and closing of the nano-pore by a photoresponse functional group, and the closing and opening of an ion channel can be accurately regulated and controlled through the alternate irradiation of ultraviolet light and visible light, so that the transmission membrane has a good application prospect. And the controllability of light-operated ion transmission is finally realized.

The invention belongs to the technical field of dressing preparation, and particularly relates to a preparation method of a photocuring methacrylated gelatin hydrogel dressing, which comprises the following steps: step 1, dissolving methacrylated gelatin in a phosphate buffer solution to prepare a methacrylated gelatin solution with the mass concentration of 5-15%; 2, adding a natural photoinitiator into the solution obtained in the step 1, and uniformly stirring and mixing; 3, adding the traditional Chinese medicine active ingredient powder, and stirring until the powder is uniformly dispersed to obtain a mixed solution; and 4, pouring the mixed solution into a mold, and curing and molding under the irradiation of visible light. Chlorophyll or riboflavin is used as a natural photoinitiator and is directly dispersed in a methacrylated gelatin solution in a physical blending mode, a curing light source enables chlorophyll to completely avoid a chemical initiator, meanwhile, the process is simplified into physical stirring to replace nanoparticle synthesis and modification, visible light reduces the risk of tissue burn, the production cost is reduced, and the method is suitable for industrial production. The method is suitable for primary medicine.

The invention discloses a preparation method of CoWO (cobalt tungsten oxide) modified NbOp-n heterojunction NbO5 / CoWO photocatalyst powder. The preparation method comprises the following steps: dissolving cobalt salt and tungsten salt in deionized water, stirring and mixing, carrying out hydrothermal reaction in an autoclave, washing and drying to obtain CoWO powder; the preparation method comprises the following steps: dissolving niobium oxalate and ammonium carbonate in deionized water, adding CoWO powder, carrying out a hydrothermal reaction in an autoclave, and carrying out washing and drying treatment to prepare NbO / CoWO photocatalyst powder. According to the method, the hydrothermal reaction temperature is regulated and controlled, and the mass ratio of raw materials is optimized, so that the catalyst forms a p-n heterojunction structure of NbOmicron flower loaded CoWOnano particles. The prepared catalyst has high norfloxacin wastewater degradation efficiency under visible light irradiation, has the advantages of simple preparation process, low reagent cost, high catalytic activity and good structural stability, and can be effectively applied to purification treatment of antibiotic polluted water.

The invention provides a double-defect-modified porous carbon nitride photocatalyst prepared by one step from ferromolybdic acid as well as a preparation method and application of the double-defect-modified porous carbon nitride photocatalyst. The catalyst is of a thin-layer porous structure, so that the specific surface area of the catalyst is increased, and more surface active sites are provided for adsorption and reaction; compared with pure g-C3N4, the visible light absorption intensity of the catalyst is obviously enhanced, due to the existence of surface N vacancies and defects formed by doping of metal oxides, effective charge separation is enhanced, the photon-generated carrier separation and transfer capacity is higher under visible light irradiation, and the catalytic activity is remarkably improved. When the photocatalyst is applied to degradation of tetracycline antibiotic pollutants, photocatalytic degradation of tetracycline can be realized only under the condition of low-power 5W LED visible light, the preparation process is simple, and the cost is lower.

The invention belongs to the field of organic synthetic chemistry, and relates to a preparation method of melatonin and meerythrine indole derivatives and compounds. Specifically, the indole derivative is efficiently synthesized by taking arylamine and carboxylic acid as raw materials through a one-pot two-step reaction in the presence of catalysis of ferric chloride hexahydrate (FeCl3. 6H2O), a ligand, a diazotization reagent, an additive and a solvent under the conditions of visible light irradiation, inert atmosphere and room temperature. According to the method, visible light induced iron-based LMCT catalysis and iron lewis acid catalysis functions are integrated, and efficient integration of diazotization, decarboxylation, free radical coupling and cyclization reaction is achieved. The method has the advantages that raw materials are cheap and easy to obtain, reaction conditions are mild, substrate applicability is wide, functional group compatibility is good, operation is easy, convenient and safe, and environment friendliness is achieved, gram-level scale preparation can be achieved, and a green and efficient synthesis path is provided for indole compounds with biological activity such as melatonin and meerythrine.

The invention discloses a preparation method of a 6-alkyl aza-uracil compound, which comprises the following steps: in a nitrogen atmosphere solvent, irradiating a reaction mixture of an aza-uracil derivative and carboxylic acid active ester with visible light, adding a catalyst and stirring for reaction, and after the reaction is completed, performing column chromatography separation on the reaction mixed solution to obtain the 6-alkyl aza-uracil compound. The product 6-alkyl aza-uracil compound can be prepared. The synthesis method of the 6-alkyl aza-uracil compound provided by the invention does not need to use a photosensitizer and a metal catalyst, the reaction conditions are green and mild, and the operation is simple, convenient, rapid and efficient.

The invention discloses a preparation method of a high-stability photoresponse covalent organic framework membrane and application of the high-stability photoresponse covalent organic framework membrane in selective separation of multiple components. 4-azido azobenzene is prepared by carrying out azido reaction on 4-aminoazobenzene in an acidic aqueous solution, and then a BPTA-TAPB-COF membrane is used as a matrix to prepare the high-stability photoresponse covalent organic framework membrane. 4-azido azobenzene is efficiently grafted to the pore wall of the BPTA-TAPB-COF membrane through a click chemical reaction, the photoresponse covalent organic framework membrane is constructed, and the covalent organic framework membrane can be used for multi-component selective separation and is suitable for multi-component systems with different sizes. The azobenzene group in the pore channel of the prepared Azo-COF membrane is subjected to reversible cis-trans isomerization under the irradiation of ultraviolet / visible light, the response speed is high, and the cycle performance is good; the Azo-COF membrane has good application in the light-operated nanofiltration process, the performance of the Azo-COF membrane is not reduced after the Azo-COF membrane is continuously recycled for 12 days, and the structure of the Azo-COF membrane is kept stable.

The present invention discloses a light-responsive Pickering emulsion that is synergistically stabilized by a spiropyran ionic liquid and UiO-66-NH2. The Pickering emulsion comprises an oil-water phase, and its stabilizer is a spiropyran ionic liquid and a metal-organic framework material UiO-66-NH2. The stable Pickering emulsion can undergo demulsification under additional visible light irradiation. When further irradiated with ultraviolet light, the system can be re-emulsified to form a stable Pickering emulsion. The Pickering emulsion provided by the present invention can be used for the Click reaction of hydrophilic azide compounds and terminal alkynyl compounds. Through reversible visible light and ultraviolet light regulation, the catalyst and spiropyran ionic liquid can be recycled, and the Pickering emulsion has application value in the fields of controlled drug release and sustainable catalysis.

The invention discloses an S-type three-dimensional carbon nitride / copper sulfide nanosphere heterojunction as well as a preparation method and application thereof, and belongs to the field of antibacterial application of nano materials. The three-dimensional porous carbon nitride not only can increase photocatalytic active sites, but also can improve close contact with copper sulfide. The copper sulfide nanospheres and the three-dimensional porous nanosheets construct an S-shaped heterojunction, and efficient separation of photo-induced electrons and hole pairs can be driven under the action of a built-in electric field, band edge bending and coulomb force. The S-type three-dimensional carbon nitride / copper sulfide nanosphere heterojunction can generate more active oxygen species to inactivate bacteria through a photocatalysis-Fenton-like reaction; in addition, the photothermal effect of copper sulphide has a certain auxiliary sterilization effect. Under the conditions of visible light irradiation and trace hydrogen peroxide, the inactivation rates of the S-type three-dimensional carbon nitride / copper sulfide nanosphere heterojunction on staphylococcus aureus and escherichia coli are up to 99.5% and 99.7% respectively, and meanwhile, the S-type three-dimensional carbon nitride / copper sulfide nanosphere heterojunction has a remarkable treatment effect on wounds infected by staphylococcus aureus.

The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of an isoxazole compound under a visible light catalysis condition. The method comprises the following steps: dissolving a compound 1 in 1, 2-dichloroethane, then adding tert-butyl nitrite, tribromomethane, alkali and a photocatalyst, in an inert gas environment, irradiating with visible light and stirring at room temperature to react, after the reaction is completed, reducing pressure to remove a solvent, and then performing silica gel column purification on a crude product to obtain a product, namely the isoxazole compound. The brand-new method for preparing the isoxazole compound through visible light catalysis is developed, the conditions of high temperature and high pressure in a traditional synthesis method are avoided, energy consumption and environmental pollution are remarkably reduced, and the yield of the isoxazole compound is effectively increased by regulating and controlling reaction conditions and optimizing raw material selection and proportion.

According to the yellow leuco dye developing ink and the preparation method thereof disclosed by the invention, by optimizing the molecular structure of the yellow leuco dye and the matching relationship between the yellow leuco dye and a color developing agent, the ink can quickly develop under the conditions of low temperature, slight pressure or low-concentration acid / metal salt, the developing effect is distinct, and handwriting or patterns are clear and visible; by selecting a yellow leuco dye with better photostability of a color body after color development and introducing an antioxidant component, the color fading of a color development product under the irradiation of ultraviolet and visible light is effectively delayed, and the storage period of color development images and texts is prolonged; by improving an ink formula and a packaging process, the ink can keep good leuco stability in different environments such as high temperature, high humidity, low temperature and the like, and the phenomena of self color development, non-uniform color development and the like are prevented. The ink is colorless or light in color under normal conditions, can show bright yellow after being stimulated by acid, metal salt or heat, and has the characteristics of high color developing sensitivity, clean background and wide application range, and the comprehensive performance of the ink is remarkably improved.

The invention provides a visible light photocatalytic hydrogen production material based on a D-pi-A type PTA-TFPTA imine bond COF as well as a preparation method and application of the visible light photocatalytic hydrogen production material, belongs to the technical field of functional material technologies and photocatalytic hydrogen production, and is used for solving the problem that a covalent organic framework material is generally insufficient in catalytic activity in the photocatalytic hydrogen production process. The material is prepared by mixing and reacting 2, 5, 8, 11-tetra (4-aminophenyl) perylene and an electron-deficient monomer; during application, the material is mixed with a sacrificial agent and a cocatalyst, and photocatalytic hydrogen production can be realized under visible light irradiation. The preparation process is simple and convenient, does not need complex equipment and harsh conditions, and is easy for large-scale production; the obtained material is good in crystallinity, excellent in visible light absorption performance and outstanding in photocatalytic hydrogen production activity.

The invention discloses a modified hollow cadmium sulfide photocatalytic reducing agent and a preparation method and application thereof, and belongs to the technical field of wastewater treatment.The preparation method comprises the steps that silicon dioxide microspheres and deionized water are mixed to prepare suspension liquid, a sodium citrate aqueous solution, a cadmium chloride aqueous solution, ammonia water and a thiourea aqueous solution are added into the suspension liquid, the mixture is stirred to be uniform and then heated for a reaction, and the modified hollow cadmium sulfide photocatalytic reducing agent is obtained; preparing to obtain a silicon dioxide and cadmium sulfide composite material; immersing the silicon dioxide and cadmium sulfide composite material into a sodium hydroxide solution, heating and etching to obtain nano hollow cadmium sulfide; the preparation method comprises the following steps: immersing nano hollow cadmium sulfide into a 1-octadecene solution, carrying out heating reaction, and carrying out alcohol washing and drying to obtain the modified hollow cadmium sulfide photocatalytic reducing agent. The modified hollow cadmium sulfide composite photocatalyst is synthesized through a silicon dioxide template method and a thermal decomposition method, and high-concentration methyl orange industrial wastewater can be efficiently degraded under the condition of visible light irradiation.

The preparation method specifically comprises the following steps: (1) respectively preparing mother liquor containing a photosensitizer and mother liquor containing an annihilation agent by taking tetrahydrofuran as a solvent; (2) heating and volatilizing the prepared mother liquor containing the photosensitizer and the annihilation agent, then adding a polymeric monomer and a photochemical deoxygenization organic medium, then adding a photoinitiator, heating and stirring the obtained mixed system to enable solids to be fully dissolved in an organic phase so as to prepare a gel precursor; and (3) irradiating the prepared gel precursor by ultraviolet light or visible light to carry out crosslinking reaction. According to the preparation method provided by the invention, photochemical deoxidizing media PEG, DMSO and TMSO are taken as organic solvent matrixes and are crosslinked with multiple groups of polymer monomers (such as PEGDA and HEA) to form a gel network, and the gel system with up-conversion emission performance in the air environment is successfully prepared. In addition, the photo-activated deoxidizing gel prepared by the method can be successfully applied to information encryption and anti-counterfeiting technologies.

The invention belongs to the technical field of catalytic synthesis, particularly relates to a method for preparing a nitrogen-containing fused ring compound through quantum dot catalyzed [4 + 2] cycloaddition, and aims to solve the problems of limited product structure and complex reaction system in the existing synthesis method. The synthesis method disclosed by the invention comprises the following steps: in an inert atmosphere, adding 1-phenylpyrrole and fumarate as reaction raw materials, quantum dots as a photocatalyst and an organic solvent into a reaction container, carrying out [4 + 2] cycloaddition reaction under visible light irradiation, and then filtering, concentrating, separating and purifying to obtain the nitrogen-containing fused ring compound. The reaction condition is mild, and the method can be realized by irradiating the quantum dot catalyst with a visible light source at normal temperature and pressure; a reaction system is simple, strong oxidants and additives are not needed, operation steps are convenient, and atom economy is achieved.

The invention discloses a synthesis method of a glutaric acid ester compound, which comprises the following steps: reacting a propionate compound as shown in a formula 1 with a diazo compound as shown in a formula 2 in a solvent in a nitrogen atmosphere in the presence of a reducing agent under the illumination condition of visible light, and after the reaction is completed, separating out the glutaric acid ester compound, thereby obtaining the glutaric acid ester compound. And separating and purifying the reaction mixture to obtain the glutaric acid ester compound as shown in the formula 3. The propionate compound and the diazo compound are used as reaction substrates, the compound can be generated through reaction under mild conditions, the yield of the target product is improved, operation is easy and convenient, the reaction conditions are mild, the price of raw materials and solvents used in the whole process is low, and cost control is facilitated.

The invention discloses a photocatalytic synthesis method of diethyl disulfide, and relates to the technical field of organic synthesis. The preparation method specifically comprises the following steps: mixing Co (NO3) 2.6 H2O and Ni (NO3) 2.6 H2O, and adding methanol to obtain a solution A; 2-methylimidazole and methyl alcohol are mixed, and a solution B is obtained; mixing the solution A and the solution B to obtain a zeolite imidazole framework material; selenium powder and the zeolite imidazole framework material are mixed and calcined, and a NiCoSe2 material is obtained; the preparation method comprises the following steps: mixing a NiCoSe2 material, ZnCl2, InCl3 and C2H5NS, adding an ethanol water solution, and carrying out microwave hydrothermal synthesis to obtain a NiCoSe2-coated ZnIn2S4 photocatalyst; the NiCoSe2-coated ZnIn2S4 photocatalyst and ethanethiol are subjected to a photocatalytic reaction under N2 atmosphere protection and visible light irradiation, and diethyl disulfide and hydrogen are generated. The method is mild in reaction condition and high in product stability.

The invention belongs to the technical field of biomedical materials, and discloses a viola philippica exosome-loaded composite hydrogel as well as a preparation method and application thereof, the composite hydrogel is prepared by mixing methacrylated polylysine (PLMA), oxidized dextran (ODex), viola philippica exosome (V-E), a photoinitiator and a physiologically compatible solvent and performing illumination crosslinking; the preparation method comprises the following steps: respectively preparing PLMA and ODex solutions, extracting and purifying V-E, adding a photo-crosslinking agent (LAP), mixing the components to obtain a precursor liquid, and carrying out in-situ curing molding through ultraviolet-visible light irradiation. The composite hydrogel provided by the invention solves the problems that the existing wound dressing is difficult to fit with irregular wounds, is antibacterial and easy to resist drugs, and lacks active anti-inflammatory and efficient healing promotion capabilities, and is suitable for repair treatment of infectious open wounds such as burns, trauma, diabetic foot ulcer and postoperative infected incisions.

The invention discloses application of bismuth vanadium tetraoxide as a photocatalyst in preparation of allantoin. According to the method, a decahedral single crystal micron material bismuth vanadium tetroxide is used as a photocatalyst, uric acid is used as a substrate, a photocatalytic reaction is performed under the irradiation of visible light, and uric acid is oxidized, hydrolyzed, decarboxylated and converted into allantoin; compared with a traditional chemical synthesis method, the method has the advantages that the bismuth vanadium tetraoxide serves as a photocatalyst, uric acid is converted into allantoin through photocatalytic reaction, selective activation of chemical bonds is achieved through directional regulation and control of photo-induced electron-hole pairs, and the method is mild in reaction condition, low in energy consumption and the like.

The present invention relates to a method for functionalizing a biopolymer having an -OH group or an -NH2 group by reacting the biopolymer with at least one compound having at least one C=C bond or C≡C bond and containing a chromophore that absorbs UV-Vis radiation directly adjacent to this bond. The present invention also relates to a method for obtaining a solid biopolymer material by reversibly crosslinking the functionalized biopolymer obtained by the above method under UV-Vis light irradiation. Furthermore, the present invention relates to the use of functionalized biopolymers as support materials for 3D bioprinting, or as materials for manufacturing structures selected from spheroids, organoids, artificial organs, coatings, and tissue models.

The present invention relates to the field of electronic device technology, and in particular to a single-molecule photoelectric memristor based on a photoresponsive axis molecule and a preparation method thereof. The single-molecule photoelectric memristor comprises a photoresponsive axis molecule and a graphene dot electrode pair, wherein the photoresponsive axis molecule is connected between the graphene dot electrode pair. When ultraviolet light irradiates the photoresponsive axis molecule, a high-conductance state appears when the axis molecule rotates, and when visible light irradiates the photoresponsive axis molecule, a low-conductance state appears when the axis molecule rotates. Based on this, the single-molecule photoelectric memristor has a high-low conductance bistability state, which can achieve rapid and reversible changes in conductance state, thereby improving response speed, operating efficiency, performance stability, flexibility and adaptability. The single-molecule photoelectric memristor provided by the present invention is expected to be widely used in fields such as neuromorphic computing, artificial intelligence and brain-like computing. The preparation method provided by the present invention is simple to operate, has mild reaction conditions, and is conducive to industrial production.

A light-emitting device (1) is attached to a support body of a mobile body (100) alongside an imaging device (2), and emits invisible light which is detected by the imaging device (2) toward the ground. In the light-emitting device (1), a position (PP) of peak illuminance in an irradiation region (IA) of the invisible light with which the ground is irradiated is present at a position away from the support body. The irradiation region (IA) includes a first region (A1) including the position (PP) of peak illuminance, and a second region (A2) surrounding the first region (A1). When irradiance with which a white line (210) drawn on the ground can be detected is defined as white line irradiance, the first region (A1) is a region irradiated with the invisible light at an irradiance equal to or higher than the white line irradiance, and the second region (A2) is a region irradiated with the invisible light at an irradiance lower than the white line irradiance.

A drawing apparatus draws an illumination image by illuminating visible light onto a landing point on which a flight vehicle is to land. The drawing apparatus includes a focusing mechanism that executes focusing of the illumination image according to an altitude of the flight vehicle, and an illumination angle adjustment mechanism that adjusts an illumination angle of the visible light toward the landing point.

The present invention provides a synthesis method and application of high-value nitrogen-containing compounds by photocatalytic reduction of nitrogen-containing small molecules. The synthesis method comprises the following steps: mixing a photocatalyst, a nitrogen-containing small molecule, and an electron donor, adding or not adding a co-catalyst, preparing a reaction solution, introducing an inert gas into the reaction solution and sealing it, and irradiating the reaction solution with visible light to obtain the high-value nitrogen-containing compound; wherein the nitrogen-containing small molecule comprises one or more of N2, NO, N2O, nitrate, and nitrite; and the photocatalyst comprises one or more of CdS, CdSe, ZnSe, CuInS2, CdSe / ZnS, CdSe / CdS, ZnSe / CdS, CdSe / ZnSe, CdS / ZnS, CdSe / CdS / ZnS, CdS / TiO2, and CdSe / TiO2. This synthesis method can utilize nitrogen-containing small molecules for efficient reduction to obtain high-value nitrogen-containing compounds such as NH3, urea or cyclohexanone oxime, and has high synthetic application value. At the same time, this synthesis method has mild reaction conditions, high visible light utilization rate, cheap and easily available raw materials, and strong applicability.

The application discloses a functionalized gold-silver nanowire alloy composite photoelectric material and a preparation method and application thereof. A pillar[6]arene molecule AuAg@WP6 capable of undergoing host-guest complexation with a serotonin molecule 5- HT is wrapped on the surface of gold-silver nanowire alloy AuAg NWs, and the AuAg@WP6 / rGO-C3N4 is loaded on a reduced graphene oxide and carbon nitride rGO-C3N4 composite material to design a PEC biosensing system. The AuAg@WP6 / rGO-C3N4 serves as a sensing material. The LSPR effect of the AuAg NWs under visible light irradiation promotes charge separation. The host-guest complexation of the WP6 can selectively adsorb a large amount of 5- HT to the surface of the material. Since the g-C3N4 and the rGO have similar pi-conjugated structures, the two are easy to be bonded to form the rGO-C3N4 composite material. The photo-induced holes on the rGO-C3N4 can accelerate the oxidation of the serotonin molecule, and further improve the photocurrent response to detect 5- HT. Based on the excellent photoelectrochemical performance of the composite material, the linear range for detecting 5- HT is 0.01-100 muM, and the detection limit is 2 nM (S / N=3).

This invention discloses a Cu2O / Cu3VO4 heterojunction catalyst, its preparation method, and its application in the photocatalytic reduction of CO2 to multi-carbon products, belonging to the field of catalyst materials technology. The preparation method includes: dissolving a copper source and a vanadium source in water to obtain a solution; mixing the solutions and adjusting the pH to 5-8 to obtain an initial solution; dispersing the solid from the initial solution after centrifugation in a mixture of ethylene glycol and water; and performing a hydrothermal reaction at 150-200℃ for 8-12 hours; washing and drying the reactants, and then calcining them at 500-600℃ for 2-5 hours under an inert atmosphere to obtain the Cu2O / Cu3VO4 heterojunction catalyst. In this catalyst, Cu2O and Cu3VO4 form a closely contacted heterojunction structure, enabling efficient separation of photogenerated electrons and holes under a built-in electric field and enhancing the absorption of visible light. Under visible light irradiation, this catalyst can reduce CO2 to multi-carbon products such as CO, CH4, C2H4, and C2H6, with an electron selectivity of up to 79% for the C2 products. The preparation process of this invention is simple and low-cost, and the resulting catalyst has broad application prospects in the field of photocatalytic CO2 reduction.

To provide a method for efficiently decomposing water into hydrogen and oxygen even under visible light irradiation by using a hydrogen-generating photocatalyst. The method for splitting water by light of the present invention is a method in which light is irradiated onto an aqueous solution containing one type of photocatalyst and a compound having oxidation-reduction ability dissolved therein.

The invention discloses a composite catalyst for anchoring coordinated copper anion micromolecules (preferably [Cu (BCA)] <->) in a cationic covalent organic framework (preferably EBCOF) skeleton pore channel through an ion exchange strategy, and a preparation method and application thereof. According to the catalyst, a directional electron transmission channel composed of a COF framework-ionic bond-anion copper complex is constructed in a COF body, the catalyst is used for CO2 reduction reaction under the conditions of visible light irradiation and triethanolamine as a sacrificial agent, high selectivity is shown for C2 products, the ethane generation activity is improved by about 2.62 times compared with a control sample not subjected to ion exchange treatment, and the selectivity of the catalyst is greatly improved. And the activity retention rate is not less than 90% after circulation for 5 times. The method is simple in process and mild in condition.