323 results about "Layered double hydroxides" patented technology

The invention provides a low-temperature-impact-resistant food packaging material and a preparation method and application thereof.The low-temperature-impact-resistant food packaging material is prepared from, by mass, 100 parts of polylactic acid, 1-10 parts of modified layered double hydroxide and 5-40 parts of hyperbranched polyester; wherein the modified layered double hydroxide is obtained by treating layered double hydroxide with a composite anionic surfactant and then treating the treated layered double hydroxide with an organic cationic compound with a long alkyl chain; the composite anionic surfactant comprises a first anionic surfactant and a second anionic surfactant; wherein the first anionic surfactant comprises sodium dodecyl sulfate; the second anionic surfactant comprises a sulfonate anionic surfactant containing an amido bond and a catechol structure. Through the formula design, the impact toughness of the material at low temperature can be improved while the mechanical property of polylactic acid is maintained, and the material can be suitable for the field of food packaging.

The invention discloses a compostable and reslurrable mineral-based dual-scale barrier coating as well as preparation and application thereof, and belongs to the technical field of water-based and reslurrable barrier materials. In order to overcome the defects of high coating weight, large color difference or difficulty in recovery in the prior art, a compact barrier is constructed through double-scale collaborative design of interlayer intercalation of layered double hydroxides and interparticle metal micro-networks. The method has the prominent advantage that high-efficiency water-oxygen barrier better than that of a conventional scheme can be realized only by using an extremely low coating amount. Meanwhile, the coating strictly controls color difference to maintain high whiteness of the paper, has pH responsiveness, can be quickly unlapped and dispersed under an acidic condition, and is easy to re-pulp. The coating does not contain PFAS and PVDC, and unification of high barrier, high whiteness and recoverability is achieved.

The application discloses an electrochemiluminescence immunosensor for detecting interleukin-1 beta and a preparation method and application thereof, and comprises a three-electrode system of a working electrode, a reference electrode and a counter electrode; the working electrode is a modified electrode of CoAl layered double hydroxide, is loaded with platinum nanoparticles after being etched by alkali, and is obtained by fixing interleukin-1 beta antibodies and blocking non-specific sites; and a solution containing luminol is used as an electrolyte during detection of the immunosensor. The working electrode of the immunosensor takes oxygen-rich vacancy CoAl layered double hydroxide as a substrate, combines with platinum nanoparticles to realize EMSI effect, significantly enhances the electrochemiluminescence signal of a luminol-dissolved oxygen system, realizes quantitative detection of IL-1 beta by combining with specific antigen-antibody recognition, and has the characteristics of strong anti-interference ability, fast detection speed and good stability.

The invention discloses a tetrathiomolybdate intercalated ternary iron-magnesium-zinc layered double hydroxide catalyst, a preparation method thereof and an application of the tetrathiomolybdate intercalated ternary iron-magnesium-zinc layered double hydroxide catalyst in degrading azo dyes by activating peroxymonosulfate. According to the method, a carbonate intercalated ternary LDH precursor is synthesized through a hydrothermal reaction, interlayer anions are replaced with nitrate and tetrathiomolybdate through ion exchange, and the target catalyst is obtained. In the catalyst, a unique Fe-Mg-Zn ternary metal laminate and a MoS < 2-> intercalation structure cooperatively construct a multi-active center, and MoS < 2-> is used as an electron donor to promote cyclic regeneration of Fe < 3 + > / Fe < 2 + >. The catalyst keeps ultrahigh activity in a wide range of pH (potential of hydrogen) of 3-9, can completely degrade 10 mg / L of acid orange 7 within 5 minutes, and is stable in structure and low in metal dissolution risk. The problems of low activity, slow Fe < 3 + > reduction, metal ion dissolution and the like under neutral and alkaline conditions in an advanced oxidation technology based on peroxymonosulfate are solved, and the method has important application value in the field of printing and dyeing wastewater treatment.

The invention provides a chlorine corrosion resistant cathode for electrolyzing seawater as well as a preparation method and application of the chlorine corrosion resistant cathode. The preparation method comprises the following steps: S1, dissolving a cobalt salt, a nickel salt, a morphology regulating agent and a structure-directing agent in a solvent according to a molar ratio of (1-2.5): (1-2.5): (8-12): (6-10), and stirring to form a first solution; s2, a titanium mesh and the first solution are subjected to a hydrothermal reaction at the temperature of 100-150 DEG C, and CoNi layered double hydroxide with the shape of a nanoneedle array grows on the titanium mesh in situ; s3, selenium powder and a reducing agent are dissolved in a solvent according to the molar ratio of 1: (0.8-1.5) and stirred to form a second solution; and S4, carrying out hydrothermal reaction on the titanium mesh on which the CoNi layered double hydroxides grow in situ and a second solution at 150-190 DEG C so as to grow cobalt-nickel bimetallic selenide of which the morphology is a nanoneedle array in situ on the titanium mesh, thereby obtaining the chlorine corrosion resistant cathode.

The invention relates to the technical field of metal surface protective coatings, in particular to a corrosion-resistant coating for a building aluminum template and a preparation method of the corrosion-resistant coating. The problems that a coating is prone to failure under the stress-corrosion synergistic effect, and the protection service life is short are solved. The coating comprises an organic silicon hybrid bottom layer, a dual-carrier corrosion inhibitor energy storage layer, a microcapsule self-repairing layer and a wear-resistant super-hydrophobic top layer. An oxidized ceramic layer is generated on the surface through micro-arc oxidation, and then a bottom layer is formed through dip-coating of organic silicon hybrid sol and curing; dispersing the porous silicon dioxide microspheres loaded with the corrosion inhibitor and layered double hydroxides in water-based resin to prepare an energy storage coating, and forming a corrosion inhibition energy storage layer; urea resin microcapsules and gelatin-Arabic gum microcapsules are added into a resin matrix to prepare a self-repairing coating, and a self-repairing layer is formed; and finally, mixing the fluorosilane-modified nano aluminum oxide and nano silicon dioxide with wear-resistant organic silicon resin to form a super-hydrophobic top layer.

The invention belongs to the technical field of civil engineering materials, and particularly relates to sprayed concrete suitable for a chlorine salt erosion environment and a preparation method of the sprayed concrete. And meanwhile, the bionic helical carbon nanotube-polymer composite gel is pre-dispersed in water. Sequentially adding the aggregate, the fiber and the composite cementing material, carrying out dry mixing, adding the gel dispersion liquid, the water reducing agent and the air entraining agent, and stirring to obtain a mixture; and finally, adding an alkali-free liquid accelerator at a nozzle through a wet spraying process, and spraying the alkali-free liquid accelerator to a construction surface. The nano hybrid material can effectively adsorb and lock chloride ions, and the bionic gel has a crack self-repairing function. And the two components have a synergistic effect, and are combined with a compact microstructure and a fiber reinforcing and toughening effect, so that the obtained concrete has extremely high chloride ion penetration resistance and durability, and is particularly suitable for support and protection engineering in chlorine salt environments such as temporary expressways and the like.

The invention discloses a preparation method and application of a high-entropy layered double hydroxide oxygen evolution catalyst, and relates to the field of oxygen evolution reaction catalysis, and the preparation method comprises the following steps: S1, washing foamed nickel in absolute ethyl alcohol and deionized water, and then carrying out ultrasonic treatment in a hydrochloric acid solution to obtain pretreated foamed nickel; s2, adding ferric salt, cobalt salt, nickel salt, manganese salt, zinc salt and a proper amount of urea into deionized water, then adding ammonium fluoride, and uniformly stirring to obtain a mixed solution; and S3, transferring the mixed solution and the pretreated foamed nickel into a reaction kettle, carrying out a hydrothermal reaction, and washing and drying the obtained product to obtain the high-entropy layered double hydroxide oxygen evolution catalyst. According to the method, the key regulation and control effect of NH4F on the structure, chemical and electro-catalytic properties of HELDHs in the synthesis process of the HELDHs is analyzed, and the performance enhancement is attributed to NH4F-induced morphology and crystal engineering and catalytic active cation vacancies generated in situ through selective leaching of Zn < 2 + > and adsorption of sulfate under the alkaline condition.

The application discloses a wear-resistant copper alloy material and a preparation method thereof, and belongs to the technical field of alloy manufacturing. The wear-resistant copper alloy material comprises a copper-aluminum alloy and a surface coating. The copper-aluminum alloy comprises the following components: electrolytic copper powder, aluminum material, iron powder, manganese powder and graphene / Ni-Fe layered double hydroxide composite. The aluminum material comprises pure aluminum and coconut shell fiber / waste aluminum composite, and the mass ratio of the pure aluminum to the coconut shell fiber / waste aluminum composite is 1:(5-6). The surface coating comprises the following components: lignin-modified MXene / metal organic framework / g-C3N4 composite material, epoxy-modified isocyanate oligomer and silane coupling agent-modified nano-silicon sol. The application solves the problem of internal and external defects caused by waste aluminum in the preparation process of the copper-aluminum alloy.

The invention relates to the technical field of metallocene polyolefin materials, and particularly discloses a modified polyolefin film material as well as a preparation method and application thereof. The film material is prepared from the following components in parts by weight: 50 to 70 parts of metallocene linear low-density polyethylene, 20 to 35 parts of ethylene-butyl acrylate copolymer, 15 to 25 parts of polyolefin elastomer, 5 to 15 parts of bio-based degradable polyester elastomer, 3 to 8 parts of reactive compatilizer, 5 to 15 parts of organic modified layered double hydroxide, 8 to 20 parts of composite flame retardant, 0.3 to 1.5 parts of antioxidant and 0.5 to 1.5 parts of lubricant. The preparation method comprises the steps of melt blending, casting extrusion, two-way stretching and the like. The thin film has low hardness, high elongation, low melting point and moderate mechanical strength, the performance of the thin film can accurately meet specific application requirements, and the thin film is particularly suitable for the field of composite fabric of clothes, bags, shoes, hats and the like with high requirements for touch feeling and elasticity.

The invention relates to a collagenase-loaded LDH (layered double hydroxide) / EDTA (ethylene diamine tetraacetic acid) layered double hydroxide nano material as well as a preparation method and application thereof. The collagenase-loaded LDH / EDTA layered double hydroxide nano material is prepared from a zinc-aluminum layered double hydroxide LDH carrier, ethylenediamine tetraacetic acid EDTA inserted between layers of the LDH carrier through anion exchange, and collagenase loaded on the surface of the LDH carrier through an electrostatic adsorption effect. The invention further discloses a preparation method of the collagenase-loaded LDH / EDTA layered double hydroxide nano material for preparing the collagenase-loaded LDH / EDTA layered double hydroxide nano material for preparing the collagenase-loaded LDH / EDTA layered double hydroxide nano material.

The invention discloses a nickel-cobalt layered double hydroxide for a supercapacitor and a preparation method and application thereof, and belongs to the technical field of energy storage. The preparation method of the nickel-cobalt layered double hydroxide for the supercapacitor comprises the following steps: performing hydrothermal reaction on nickel salt, cobalt salt, ammonium citrate and urea to obtain the nickel-cobalt layered double hydroxide, the temperature of the hydrothermal reaction is 120-150 DEG C, and the time of the hydrothermal reaction is 6-12 hours. According to the invention, ammonium citrate is added to regulate the precipitation rate of the precursor, so that the morphology of the nickel-cobalt layered double hydroxide can be regulated and controlled, and the situation that the nickel-cobalt layered double hydroxide is rapidly combined with hydroxyl ions to cause too fast crystallization and coarse crystal grains is avoided; and meanwhile, the concentration uniformity of metal ions in the solution is regulated and controlled, so that the crystallinity of the nickel-cobalt layered double hydroxide is uniform, and lattice defects are reduced. Therefore, when the material is used as an electrode material of a supercapacitor, the material has relatively high specific discharge capacity.

The invention discloses a sustained and controlled release value-added fertilizer containing a bioactive carrier and a preparation method of the sustained and controlled release value-added fertilizer, and belongs to the technical field of sustained and controlled release fertilizers. The slow / controlled-release value-added fertilizer is prepared by compounding a bioactive carrier and an NPK compound fertilizer, wherein the bioactive carrier is prepared from three parts, namely a charcoal-layered double-metal hydroxide composite base material, interlayer intercalation phosphate radicals and surface-loaded humic acid. High-amount uniform loading of layered double hydroxides on the surface of biochar is achieved through a hydrothermal in-situ growth technology, phosphate radicals are stably embedded between layers in a subject-object composite mode, and a humic acid active component is combined to form a novel value-added fertilizer with multiple functions of nutrient slow release, soil improvement and growth stimulation. The fertilizer utilization rate is effectively improved, and the nutrient loss risk is reduced.

The present application relates to the field of microcapsules, and discloses a flame-retardant temperature-regulating phase change microcapsule and application thereof in polystyrene foam plastic. The polystyrene foam plastic contains carbon nanotube / magnesium-aluminum layered double hydroxide modified silica coated paraffin phase change microcapsules, the carbon nanotube / magnesium-aluminum layered double hydroxide modified silica wall material has high thermal conductivity, and the magnesium-aluminum layered double hydroxide generates water vapor when decomposed under heat, which dilutes combustible gas, and the decomposition products, silica and carbon nanotubes synergistically promote carbonization to form a dense carbon layer, achieving the effect of flame retardation. When the microcapsules are used as fillers of polystyrene foam plastic, the polystyrene foam plastic has good flame retardation and energy storage temperature regulation effects.

The application provides a biomass-based composite electrode material, an electrode sheet and a hybrid supercapacitor, and belongs to the technical field of electrochemical energy storage. 3 The biomass-based composite electrode material comprises: a biomass-derived porous carbon matrix, pores with multiple pore sizes, the volume of the pores is 0.7-1.7 cm 2 / g; and nickel-cobalt layered double hydroxide nanosheets vertically anchored on the surface of the biomass-derived porous carbon matrix; the specific surface area of the composite electrode material is 900-1400 m 2 / g. The biomass-based composite electrode material of the application significantly improves the ion adsorption and charge storage capacity. In addition, the electrode material is applied in a capacitor, which effectively improves the energy density, electrode conductivity and cycle stability of the supercapacitor.

The invention discloses a preparation method of an LDH (layered double hydroxide) membrane for a micro-nano bubble device, which comprises the following steps: putting an ultrafiltration membrane into a composite solution consisting of magnesium chloride and nitrate for soaking, uniformly dispersing by ultrasonic waves, and transferring into a reaction kettle for hydrothermal reaction to obtain the LDH membrane. The invention also discloses application of the LDH film. Magnesium chloride and nitrate are adopted to perform hydrothermal reaction on an ultrafiltration membrane to obtain an LDH-loaded filter membrane product (LDH membrane), and the LDH membrane has a unique layered structure and excellent anion exchange performance, is mainly applied to the field of heavy metal wastewater treatment, and has a wide application prospect.

This invention discloses a NiAlEu-LDHs photocatalyst, its preparation method, and its application in catalytic CO2 synthesis of syngas, belonging to the field of catalyst preparation technology. The NiAlEu-LDHs photocatalyst is a europium-doped layered double hydroxide prepared by a hydrothermal reaction using nickel, aluminum, and europium sources, possessing a multi-level nanoflower-like structure assembled from nanosheets. The preparation method includes the following steps: a one-step hydrothermal method is used to dissolve the nickel, aluminum, and europium sources, along with urea and ammonium fluoride, in deionized water; the solution is then transferred to a polytetrafluoroethylene-lined autoclave for hydrothermal reaction. This invention introduces europium through a one-step hydrothermal method, constructing a europium-doped nanoflower-like NiAlEu-LDHs photocatalyst. In production applications, this invention's preparation method is simple and novel, with low synthesis cost, easy mass production, and significant application value.

The invention discloses an iron-doped nickel-cobalt metaphosphate electrode material based on an oxide intermediate and a preparation method and application thereof, and relates to the technical field of supercapacitors, the preparation method comprises the following steps: preparing an electrolyte containing a nickel salt, a cobalt salt and an iron salt, and carrying out electro-deposition on a conductive substrate to obtain the iron-doped nickel-cobalt metaphosphate electrode material. A nickel-cobalt-iron layered double hydroxide precursor is obtained; sintering the nickel-cobalt-iron layered double hydroxide precursor to prepare an intermediate; and phosphating the intermediate by taking sodium hypophosphite as a phosphorus source to finish the preparation. The invention also discloses the iron-doped nickel-cobalt metaphosphate electrode material based on the oxide intermediate prepared by the method and an application of the iron-doped nickel-cobalt metaphosphate electrode material in preparation of a supercapacitor. Through a unique pre-oxidation process and substrate optimization, the electrochemical performance of the electrode material is remarkably improved, and the problems that an existing metaphosphate material is poor in conductivity and insufficient in active site are solved.

The invention belongs to the technical field of lubricating materials, and particularly relates to a triazole type metal deactivator as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) mixing 1, 2, 4-triazole, formaldehyde and dialkylamine, heating, adding a catalyst and layered double hydroxide, and reacting to obtain a mixture 1; and (2) fractionating and dehydrating the mixture 1, stirring and reacting, cooling and washing to obtain the triazole type metal deactivator. The triazole type metal deactivator provided by the invention has the advantages of simple preparation process, small catalyst dosage, low cost, environment-friendly reaction system and mild reaction conditions.

The invention belongs to the technical field of comprehensive utilization of coal gangue resources, and particularly relates to a layered double-metal hydroxide composite gel flame-retardant material based on coal gangue and a preparation method and application of the layered double-metal hydroxide composite gel flame-retardant material based on the coal gangue. The method comprises the following steps: preparing an acid leaching solution by taking coal gangue as a silicon-aluminum source in a deep eutectic solvent system, and adding metal salt into the acid leaching solution to provide divalent and trivalent metal ions required by a bimetal system; and mixing the pickle liquor with the guar gum / bentonite composite gel to form the composite gel flame-retardant material with a gel support structure. According to the invention, the resource utilization of a large amount of solid waste of the coal gangue is realized, the method also has a green low-consumption process and excellent flame-retardant inhibition performance, and can be widely applied to spontaneous combustion inhibition of a coal gangue storage yard, flame-retardant protection in a coal storage and transportation process and environment-friendly flame-retardant fillers in polymer composite materials and building materials.

[Problem] The present invention provides a surface-treated member which uses a steel material as a starting material and is capable of exhibiting excellent corrosion resistance even in soil at a depth of about several cm from the soil surface. [Solution] A surface-treated member according to the present invention comprises: a steel material that serves as a base material; and a protective layer that is positioned on the surface of the steel material. The protective layer has a Zn concentration of not less than 5.00 mass% but less than 30.00 mass%, an Si concentration of not less than 5.00 mass% but less than 25.00 mass%, and contains SiO2 and a Zn / Al-based carbonate type layered double hydroxide.

This invention belongs to the technical field of catalytic materials for hydrogen production through water electrolysis, specifically relating to an oxygen evolution reaction catalyst, its preparation method, and its application. The catalyst has the general chemical formula M-M1M2 LDH, where M1 and M2 are one of Fe, Co, and Ni, respectively, and M1 and M2 are not the same element. M is one of V, Cr, Mn, Co, Cu, Zn, Mo, Ce, and Zr. It is prepared using the sol-gel method. This invention optimizes the electronic structure of layered double hydroxides by controllably doping with transition metal elements, synthesizing transition metal-doped layered double hydroxides with a particle size of less than 5 nm, which are used as catalysts for the oxygen evolution reaction and exhibit good electrocatalytic activity. The preparation process of this material is simple and low-cost, providing a new strategy for the development and large-scale production of efficient and stable water electrolysis catalysts.

The invention belongs to the technical field of electrochemical catalytic materials, and relates to an efficient non-iridium nickel-based catalyst and a preparation method thereof. Comprising a nitrogen-sulfur bifunctional in-situ doped and modified nickel-cobalt layered double hydroxide nanosheet, 2, 5-dihydroxy terephthalamide, a conductive carbon carrier, a pore-forming agent, a surface wetting agent and a cross-linking agent. The nickel-cobalt layered double hydroxide is prepared by carrying out hydrothermal reaction and calcination treatment on nickel nitrate hexahydrate, cobalt nitrate hexahydrate, thiourea and melamine under an alkaline condition, and synergistic doping of nitrogen and sulfur bifunctional groups is realized; organic-inorganic interface interaction is introduced into 2, 5-dihydroxy terephthalamide, so that the structural stability of the material is enhanced. According to the invention, the current density, the mass activity, the gas production volume, the stability and the turnover performance are obviously improved. According to the invention, the defects of insufficient conductivity, limited active sites and poor cycling stability of the existing nickel-cobalt-based catalyst are effectively overcome, and a new thought is provided for developing a low-cost and high-performance electrochemical catalyst.

The application belongs to the technical field of heating resistance paste, and relates to a stainless steel-based heating resistance paste and a preparation method thereof. The application provides a stainless steel-based heating resistance paste which is composed of an electrically conductive phase, a glass phase, an organic carrier and an additive. The additive is zirconium phosphate, boron carbide and layered double hydroxide. The additive provided by the application can effectively alleviate the damage of cold and hot cycles to the heating resistance, and can reduce the square resistance of the heating resistance to a certain extent.

The invention belongs to the technical field of nano material preparation, and particularly relates to a Ru / CoNiFe-LDH composite catalyst and a preparation method and application thereof. The preparation method of the Ru / CoNiFe-LDH composite catalyst comprises the following steps: by taking CoNiFe layered double hydroxide as a carrier and Ru < 3 + > as an active component, mixing a Ru source solution and a CoNiFe layered double hydroxide solution under a stirring condition, so that the Ru < 3 + > is uniformly loaded on the surface of the carrier, and centrifugally drying to obtain a precursor; under the protective atmosphere, the precursor is roasted, and the Ru / CoNiFe-LDH composite catalyst is obtained. According to the Ru / CoNiFe-LDH composite catalyst, oxygen vacancies are provided through loading of Ru, the number of active sites is increased, accelerated transfer of electrons is promoted, and then the OER performance of the Ru / CoNiFe-LDH composite catalyst is improved.

Methods of stabilizing acidic cannabinoids by intercalating the acidic cannabinoids into layered double hydroxides (LFHs) are provided. Also provided are compositions comprising the LDH-intercalated acidic cannabinoids, physiologically compatible formulations comprising the compositions and methods of using the formulations to treat a variety of diseases and conditions in subjects.

The invention belongs to the technical field of concrete materials, and particularly relates to corrosion-resistant concrete for shield tunnel segments and a preparation method of the corrosion-resistant concrete. The concrete comprises sulphoaluminate cement, fly ash, slag powder, machine-made sand, gravel, a polycarboxylate superplasticizer, a defoaming agent, water and two key modified components, wherein the two key modified components comprise a layered double hydroxide-aluminum silicate nanosheet compound and a phosphate radical intercalation modified strontium molybdate slow-release corrosion inhibitor. During preparation, firstly, all the dry materials are put into a stirrer for dry mixing, then water and the additive are added for stirring to obtain mixed slurry, and a finished product is obtained after pouring, vibrating and steam curing. Wherein the two modified compounds are synthesized through a specific process, the former can adsorb corrosive ions and refine pores, and the latter can slowly release corrosion-inhibiting ions to protect reinforcing steel bars. The prepared concrete has excellent chloride ion penetration resistance, sulfate erosion resistance and carbonization resistance, the durability is remarkably improved, and the concrete is particularly suitable for shield tunnel segments in the severe corrosion environment.

The present invention provides a method for producing layered double hydroxides with high water permeability. [Solution] The method for producing layered double hydroxide includes a production step of mixing an acidic solution and an alkaline solution to produce a slurry-like layered double hydroxide, and a filtration step of filtering the slurry-like layered double hydroxide, wherein the temperature of the layered double hydroxide in the production step is maintained at 30°C or lower and within a temperature range where it does not freeze.

The invention provides an anti-interference coagulant which comprises nano C-A-H seed crystal, lithium-aluminum layered double hydroxide, calcium aluminate powder, zwitterionic slow-release alkali, cyclic borate, hydroxyl carboxylic acid aluminum complex, redispersible latex powder and superfine quartz powder, and through a synergistic mechanism of seed crystal induction, buffer complexation, lithium slow release and carrier dispersion, the anti-interference coagulant is prepared. Under the low doping amount of 0.05-0.3 wt%, rapid condensation and early-stage high strength under the complex conditions of 5-35 DEG C, high humidity, high alkali, high sulfate radical and the like are achieved, and the high-temperature performance of the refractory material is not affected. The invention also provides a preparation method of the coagulant and an application of the coagulant in a calcium aluminate cement combined refractory material.

The invention provides a preparation method of a defect engineering regulation ultrathin LDH confinement ruthenium monatomic catalyst and application of the defect engineering regulation ultrathin LDH confinement ruthenium monatomic catalyst to photocatalytic CO2 reduction, and relates to the technical field of catalyst preparation, the catalyst adopts ultrathin cobalt-aluminum layered double hydroxide (CoAl-LDH) rich in metal vacancies as a carrier, Ru monatomic is anchored at the metal vacancies through a wet impregnation process, and the catalyst is prepared through a hydrothermal method. Ru atoms and a surrounding matrix form an unsaturated coordination environment, so that adsorption and activation of CO2 are effectively enhanced; meanwhile, highly dispersed Ru active sites not only provide abundant catalytic centers, but also regulate and control the distribution of photo-generated charges on the surface of the catalyst, promote the separation and migration of charges, and significantly inhibit electron-hole recombination. Through the mode, the invention provides a construction strategy of a monatomic catalytic material, and a brand new technical path is provided for efficient CO2 photoreduction reaction.