4593 results about "Metal salts" patented technology

An integrated carbon honeycomb structure material and its preparation method are disclosed, belonging to the field of carbon materials technology. Based on a co-sacrificial template low-temperature pyrolysis strategy, the target material can be obtained through three main steps: preparation of a metal salt-colloidal microsphere template precursor, precursor pressing and molding, and subsequent calcination and carbonization. This technology has the characteristics and advantages of simple preparation process, regular and controllable macroscopic structure of the sample (such as shape, area, and thickness), rich and tunable chemical composition, and three-dimensional interconnection of graphene carbon matrix. It has great application potential in many fields such as electrochemical energy storage, catalysis, gas separation, adsorption, and electromagnetic shielding.

A long-term fire retarding biochemical liquid composition including: a dispersing agent realized in the form of a major amount of water, for dispersing alkali metal ions dissolved in the water; a major amount of a first fire retarding agent realized in the form of a primary alkali metal salt of a nonpolymeric saturated carboxylic acid, for example, tripotassium citrate, for providing metal potassium ions dispersed in the water when the at least one alkali metal salt is dissolved in the water to form a mixed retardant solution; a minor amount of a second fire retarding agent realized in the form of a secondary alkali metal salt of a nonpolymeric saturated carboxylic acid, for example, potassium, sodium, calcium and / or magnesium benzoate, for providing benzoate ions dispersed in the water when the secondary alkali metal salt is dissolved in the mixed retardant solution, for functioning as a secondary fire retardant agent.

The invention discloses a phosphonic acid-based metal organic framework solid electrolyte as well as a preparation method and application thereof, and belongs to the technical field of solid electrolyte materials. The method comprises the following steps: mixing a metal salt, an organic phosphonic acid ligand and an organic solvent, carrying out a coordination reaction, and treating to obtain MOF powder; heating and activating the MOF powder to obtain activated MOF powder; the method comprises the following steps: mechanically grinding lithium salt and MOF powder to form a mixture, heating to enable the molten lithium salt to permeate and fill MOF channels, and cooling to obtain solid electrolyte powder. The ionic conductivity of the solid electrolyte at 30 DEG C reaches 1.01 * 10 <-4 > S cm <-1 >, and the solid electrolyte is kept stable in a 4.4 V high-voltage window. The symmetrical battery based on the phosphonic acid-based MOF solid electrolyte can stably operate, and shows excellent compatibility and stability of the electrolyte and a lithium metal negative electrode. The method has the advantages of simple operation, cheap and easily available components, and is expected to be suitable for large-scale preparation.

The invention discloses a preparation method and application of an amorphous nickel-cobalt-iron phosphate anode catalyst, and belongs to the technical field of alkaline water electrolysis hydrogen production, the preparation method comprises the following steps: (1) dissolving transition metal salt in a solvent, and stirring to obtain a metal salt solution; (2) dissolving phosphate in a solvent, and stirring to obtain a phosphate solution; and (3) adding the phosphate solution into the metal salt solution for reaction, washing with deionized water and ethanol, centrifugally separating, and drying to obtain the amorphous nickel-cobalt-iron phosphate anode catalyst. According to the preparation method and application of the amorphous nickel-cobalt-iron phosphate anode catalyst, process safety improvement and environmental friendliness optimization are achieved through an all-water-phase green synthesis system, the obtained catalyst shows excellent performance in an AEM electrolytic cell, the cell voltage is only 1.87 V under the current density of 2 A / cm, and the method has remarkable industrial application prospects.

The invention belongs to the technical field of energy storage materials, and particularly relates to a high-entropy oxide Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2O and an ultrafast synthesis method and application thereof. According to the preparation method, ferroferric oxide, cobalt oxide, nickel oxide, copper oxide and zinc oxide with equal molar ratio are adopted as direct synthesis raw materials, toxic gases such as chlorine and nitrogen dioxide generated in the synthesis process of a metal salt precursor are avoided, and the uniformly distributed single-phase high-entropy oxide is synthesized in an ultrafast manner within 10 seconds by using a Joule heating technology; the synthesized high-entropy oxide is used as a lithium ion battery negative electrode material, and shows more excellent electrochemical performance and cycling stability compared with other high-entropy oxides prepared from transition metals with different proportions; in the preparation process, extra additives are not needed, operation is easy, the synthesis speed is high, the yield is high, element distribution is uniform, and the method has the advantages of being low in cost, high in efficiency and free of pollution and has the industrialization prospect.

The invention provides anti-ionizing radiation powder with a core-shell heterogeneous gradient structure and a preparation method and application of the anti-ionizing radiation powder, and belongs to the field of radiation protection.The preparation method of the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure comprises the following steps that high-atomic-number metal salt is added into deionized water, aging, washing, drying and primary calcination are conducted in sequence, and the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure is obtained; a core layer is obtained; the core layer and low-atomic-number metal salt are added into deionized water, aging, washing, drying and primary calcination are sequentially conducted, and preliminary wrapping powder with the high-atomic-number metal core layer wrapped by low-atomic-number metal is obtained; and adding the preliminarily wrapped powder and rare earth salt into deionized water, and sequentially performing aging, washing, drying, primary calcining, secondary calcining, airflow crushing and air rotation purging to obtain the anti-ionizing radiation powder with the core-shell heterogeneous gradient structure. Through cooperation of the core-shell heterostructure, the high-atomic-number oxide, the low-atomic-number oxide and the multi-element rare earth element, the shielding performance of the material is remarkably improved.

The invention belongs to the field of photocatalytic materials, and particularly relates to a high-entropy sulfide and a preparation method and application thereof. The high-entropy sulfide is granular, the molecular general formula is (MnaFebCocCudZe) xS, x is equal to 1, and the atomic ratio of Mn to Fe to Co to Cu to Zn is a: b: c: d: e of (1-2): (1-2): (1-2): (1-2): (1-2): (1-2): (1-2). The preparation method comprises the following steps: S1, dissolving metal salt in a mixed solvent of isopropanol and glycerol according to the atomic ratio of metal elements, and carrying out solvothermal reaction to obtain a precursor; and S2, dispersing the precursor in ethanol, adding thioacetamide as a sulfur source, and carrying out solvothermal reaction to obtain the high-entropy sulfide. The high-entropy sulfide disclosed by the invention is used as a photocatalytic material and shows excellent photocatalytic performance.

The invention discloses a high-entropy nanoparticle catalytic material with a metal atom shell structure and a preparation method of the high-entropy nanoparticle catalytic material, and belongs to the technical field of preparation of catalytic materials. The preparation method comprises the following steps: dispersing a metal salt and a nanofiber precursor in an organic solvent, and carrying out electrostatic spinning to obtain a nanofiber membrane; and then calcining and pre-oxidizing the nanofiber membrane, and then carbonizing and calcining to obtain the nanofiber membrane. Wherein the selection principle of the metal salt is as follows: (n-1)-(n-2) metals are selected as an alloy substrate, and the sum of the mixing enthalpy of elements of the alloy substrate is not greater than-5kJ mol <-1 >; one or two metal elements serve as a precipitated phase, and the sum of the mixing enthalpy of the metal elements of the precipitated phase and the elements of the alloy substrate is larger than 20 kJ mol <-1 >; the high-entropy nanoparticle catalytic material obtained by the method shows relatively high catalytic activity and stability, and the method has wide universality.

The invention discloses a metal-doped carbon quantum dot as well as preparation and application of the metal-doped carbon quantum dot in a nano antibacterial agent, citric acid, urea and tea polyphenol are taken as precursors, metal salt is added, carbon dot synthesis and metal ion doping are synchronously completed in one step through a hydrothermal method, and the metal-doped carbon quantum dot is prepared; the surfaces of the metal-doped carbon quantum dots are negatively charged, and the metal-doped carbon quantum dots have peroxidase-like activity and catalase-like activity at the same time; the metal ions adopt any one of Fe < 3 + >, Cu < 2 + > and Ce < 3 + >; the metal-doped carbon quantum dots are in a sphere-like shape. The metal-doped carbon quantum dots prepared by the preparation method disclosed by the invention have peroxidase-like activity and catalase-like activity at the same time through precise doping of metal ions, and the two activities have a synergistic effect in an oral periodontitis microenvironment, so that a good antibacterial effect is achieved.

The invention relates to the technical field of flocculants, in particular to a composite flocculant containing a cationic etherifying agent and a preparation method of the composite flocculant, and the composite flocculant is prepared from the following raw materials in parts by weight: 15-20 parts of carboxymethyl guar gum, 12-15 parts of cationic konjac glucomannan, 1.2-1.5 parts of the cationic etherifying agent, 1.8-2.2 parts of a magnetic polysilicate metal salt flocculant and 0.2-0.3 part of a preservative. According to the present invention, by compounding the flocculant, the flocculated floc has magnetism and can be recovered and repeatedly utilized, and the photoresponse azobenzene structure is grafted in the cationic konjac glucomannan, such that the controllable pollutant aggregation and separation can be achieved, and the good flocculation performance can be maintained after the composite flocculant is repeatedly recovered and repeatedly utilized.

The invention discloses deep eutectic gel polymer electrolyte as well as preparation and application thereof, belongs to the technical field of battery electrolyte, solves the problems of low thermal stability, low ionic conductivity and poor mechanical property in the prior art, and comprises a bimetallic salt-eutectic solvent and a polymer chain which are dynamically crosslinked and constructed, the bimetallic salt-eutectic solvent comprises lithium ions, heterogeneous metal salt and Lewis base, and the polymer chain is formed by free radical polymerization, atom transfer radical polymerization (ATRP) or reversible addition-fragmentation chain transfer radical polymerization (RAFT). According to the invention, the deep eutectic solvent is introduced as a reaction solution, so that the organic gel monomer is subjected to photopolymerization or thermal polymerization in the solution, the elongation at break can reach more than 500%, the organic gel has excellent mechanical stretchability, a polymer network is formed by utilizing a long-chain molecular formula of a polymer chain, the deep eutectic solution is wrapped in the polymer network, and the organic gel has excellent thermal stability; and the good ionic conductivity of the electrolyte is ensured.

The present invention discloses a low-temperature conductive adhesive, which is prepared by weight using raw materials including 70-80 parts of silver powder, 20-30 parts of resin matrix, 1-10 parts of curing agent, 0.1-0.5 parts of silane coupling agent, 0.1-0.5 parts of stabilizer, and 0.1-0.5 parts of metal salt. The present invention introduces an organic metal salt into the resin matrix to reduce the contact resistance of the colloid, and after wet heat aging, maintains a lower contact resistance increase rate. The present invention adopts a combination of epoxy resin, acrylate and modified epoxy acrylic resin, and the weight of epoxy resin and acrylate is less than or equal to the weight of modified epoxy acrylic resin, so that low-temperature curing can be achieved. The present invention can achieve 60-80 ° C, 20-40 min curing, and the conductive adhesive elongation at break obtained can reach more than 8%, and before and after wet heat aging, there is a more stable and relatively small contact resistance, which is particularly suitable for the electronic field with high requirements for contact resistance.

This invention discloses a method for preparing a CuZnAlGa-based layered double hydroxide (TLH)-derived catalyst for methanol production from carbon dioxide-rich syngas. Using Cu, Zn, Al, and Ga metal salts as precursors, Na₂CO₃ and NaOH as precipitants, and a mixed alcohol-water solution as an auxiliary solvent, co-precipitation is performed under controlled temperature and pH to obtain a LDH-like catalyst precursor. After high-temperature calcination and in-situ reduction in a hydrogen atmosphere, a layered framework structure of Cu nanoparticles immobilized by oxides is obtained. The LDH-like structure provides lattice confinement, preventing Cu particle aggregation, and the interaction between Cu and the oxides enhances the catalyst surface's adsorption capacity for CO and CO₂, thereby improving the activity and stability of methanol production from carbon dioxide-rich syngas.

Adhesive compositions including a multivalent metal salt, an multidentate acidic organic compound, and an aqueous medium are disclosed. The multivalent metal salt and multidentate acidic organic compound can include, as a mixture, a carbonate salt and / or carbonic acid. The aqueous medium can include pH adjusting agent such as sodium hydroxide. The adhesive composition, upon curing, can have a porosity of 10-50%. The adhesive composition, upon curing, can include a plurality of pores. The adhesive composition can be porous, and upon curing can have a plurality of pores having a pore size of between 20 μm to 200 μm. Methods of producing the adhesive composition are disclosed. Methods of using the adhesive composition are further disclosed.

The invention belongs to the field of flame-retardant finishing of textiles, and discloses a phytic acid-based flame retardant and a preparation method of a flame-retardant cotton fabric. Natural phytic acid, polyethylene glycol, melamine and metal salt are used as main raw materials, the environment-friendly characteristic of a biomass material is combined, an efficient and environment-friendly flame retardant is prepared, the prepared flame retardant is arranged on a cotton fabric through a traditional impregnation method, and the flame retardance and smoke suppression performance of the arranged cotton fabric are greatly improved. The method not only has a good flame retardant effect, but also avoids potential hazards of a traditional flame retardant to the environment and human health, and has a wide application prospect. The flame-retardant cotton fabric can be widely applied to the fields of household textiles, protective clothing, fire-fighting equipment and the like, and has remarkable economic benefits and social benefits. The invention not only provides an efficient and environment-friendly flame retardant preparation method, but also opens up a new way for application of biomass materials in the field of flame retardance, and has important scientific significance and practical value.

The invention provides a polyimide multilayer composite membrane material as well as a preparation method and application thereof, and belongs to the technical field of gas separation. According to the method, through collaborative design of a functional support layer, a gradient MOF layer and an ultrathin selection layer structure, the problems of support layer pore seepage, MOF agglomeration, weak interface bonding and the like in an existing composite membrane material are solved. The preparation method comprises the following steps: firstly, carrying out electrostatic spinning on a polyamide acid glue solution, and synchronously introducing dopamine by adopting a chemical imidization method to prepare a functionalized polyimide fiber membrane containing hydroxyl and amino on the surface, so that the mechanical property of a supporting layer and the MOF anchoring capability are remarkably improved; growing MOF layers with different particle sizes on the surface of the fiber membrane by regulating and controlling the concentration gradient of ligand / metal salt and the reaction time, and passivating through a silane coupling agent after each step of growth so as to avoid heterogeneous nucleation and construct a gradient structure; after the MOF gradient layer is subjected to Ar plasma pretreatment to introduce hydroxyl, the ultrathin polyamide selection layer is formed by utilizing interfacial polymerization of fluorine-containing acyl chloride and a macrocyclic amine monomer, and the ultrathin polyamide selection layer is suitable for gas separation work.

The invention belongs to the technical field of heating bodies, and particularly relates to a method for preparing a sheet-shaped heating body. The preparation method comprises the following steps: stirring and dissolving lanthanum nitrate, strontium nitrate, manganese nitrate hexahydrate and a solvent to obtain a metal salt solution; preparing the metal salt solution into a precursor, wherein the precursor is a precursor solution or precursor sol; and carrying out tape casting and drying on the precursor to obtain a biscuit sheet, and carrying out glue removal treatment and sintering on the biscuit sheet to obtain the sheet-shaped heating body. According to the preparation method, a precursor system is optimized, the dispersion stability of the precursor is improved, casting, drying and sintering processes are matched, the problem of powder agglomeration is solved, the defects of green bodies are reduced, the drying shrinkage rate of green body pieces in the preparation process is reduced, the surface roughness is reduced, the stability and heat output uniformity of a heating body are improved, and the compactness is improved.

The invention relates to the technical field of composite catalyst materials, in particular to a ferrocobalt bimetal hydroxide / BCN composite material and a preparation method and application thereof.The preparation method comprises the steps that cobalt nitrate and ferric nitrate are used for preparing a metal salt solution, sodium carbonate and sodium hydroxide are used for preparing a precipitant solution, a B-doped carbon nitride BCN material is added into the metal salt solution to form a uniform suspension, and the suspension is dried to obtain the ferrocobalt bimetal hydroxide / BCN composite material; dropwise adding the precipitant solution into the suspension to obtain a precursor solution, performing hydrothermal reaction on the precursor solution, and performing centrifugal impurity removal and drying to construct a heterostructure between layered double hydroxide and BCN in situ to obtain the Co-Fe LDH-coated BCN composite material. Through boron doping and heterostructure construction, the charge separation capacity of graphite carbon nitride is enhanced, the electron migration efficiency is improved through a heterointerface structure, the metal ion release amount and the cycle stability are controlled, and the catalytic performance is remarkably improved.

The invention belongs to the technical field of lithium batteries, and particularly relates to a lithium-rich manganese-based positive electrode material and a preparation method and application thereof. The preparation method comprises the following steps: mixing a metal salt solution, a precipitator and a complexing agent, and carrying out coprecipitation reaction on an obtained coprecipitation reaction precursor solution to obtain a lithium-rich manganese-based precursor; the metal salt solution comprises a manganese element, a cobalt element and a nickel element; and mixing the lithium-rich manganese-based precursor, a lithium source, an auxiliary agent and a dispersing agent, and calcining to obtain the lithium-rich manganese-based positive electrode material, the auxiliary agent comprises a nitrogen source or a nitrogen source and a carbon source. The first discharge specific capacity, the rate capability and the cycling stability of the lithium-rich manganese-based positive electrode material can be improved, and the problems of capacity fading, discharge voltage drop and dynamic delay in an electrochemical reaction process are solved.

The invention discloses a preparation method for selectively oxidizing thioether into sulfoxide through photo-initiation, and belongs to the field of synthesis of medical compounds. The preparation method comprises the following steps that in the air atmosphere, a thioether compound is dissolved in an acetonitrile-water mixed solvent, inorganic metal salt catalysts such as ferric chloride and copper sulfate are added, the mixture reacts for 8-48 h at the temperature of 0-45 DEG C under illumination with the wavelength of 295-405 nm, selective oxidation is carried out, and the sulfoxide product is obtained, and the molar ratio of thioether to the catalysts is 5: 1. The method overcomes the problems of excessive oxidation risk, complicated operation, environmental pollution and the like caused by dependence of a noble metal catalyst and use of a strong oxidant in the existing thioether oxidation method, has the advantages of high catalytic efficiency, high yield and excellent selectivity, can greatly reduce the production cost, is suitable for later industrial synthesis and amplification, and has wide application prospects. The method has the advantages of no expensive metal catalyst or oxidant, simple preparation process, high efficiency, environmental protection, safety and cost saving.

The invention provides a catalyst, a preparation method and application thereof, and a method for preparing primary amine by catalyzing nitrile compound hydrogenation, and particularly relates to the technical field of catalyst synthesis. The catalyst comprises a nickel / cobalt-based catalyst and a metal salt; wherein the nickel / cobalt-based catalyst is selected from any one of a supported nickel / cobalt-based catalyst, a Raney nickel / cobalt catalyst or a nickel / cobalt nanocrystal; the metal salt comprises any one or a combination of at least two of tungsten salt, molybdenum salt, vanadium salt, aluminum salt and cerium salt. The metal salt and the nickel / cobalt main catalyst have a synergistic effect: the surface electron density is adjusted through electron transfer, the hydrogen dissociation and cyano adsorption activation capacities are enhanced, the hydrogenation activity is improved, and the mild condition reaction is assisted; the surface chemical environment is changed or steric hindrance is borrowed, the primary amine selectivity is improved, and byproducts are inhibited; aluminum salt, cerium salt and the like inhibit nickel / cobalt agglomeration, increase active sites, enhance stability, prolong the service life and reduce the dosage.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a spinel type metal oxide coated hard carbon composite material based on a lattice matching mechanism, and a gradient doping preparation method of the spinel type metal oxide coated hard carbon composite material can overcome the defects that a hard carbon material is low in initial coulombic efficiency (about 50%), low in lithium ion transmission rate and poor in rate capability. According to the invention, magnesium salt, aluminum salt, copper salt and other metal salts are mixed with hard carbon, a precipitant is added, and a hydrothermal method is combined with a calcination process to obtain the core-shell structure composite material with hard carbon coated with a spinel structure. The technology has the following three obvious advantages: (1) lattice adaptive design of the spar type metal oxide and the hard carbon, (2) molybdenum-copper gradient doping repair of the SEI film, and (3) stable circulation of more than 5000 times at the capacity of 350mAh / g.

The invention discloses a porphyrinyl prismatic coordination molecular cage and a preparation method and application thereof.The preparation method comprises the steps that H2TMPP, Au (III) metal salt and Pd (OAc) 2 are dissolved in a solvent, an acidity regulator is added, after hydrothermal treatment, mother liquor is removed, obtained crystals are washed, and the porphyrinyl prismatic coordination molecular cage Pd-TMPP (Au) is obtained. 6 PdCl2 units and ligand combinations (H2TMPP) x [TMPP (Pd)] y [TMPP (Au)] zClz form 10 complexes in total, and the Pd-TMPP (Au) comprises at least 5 of the complexes. According to the invention, a Pd-TMPP (Au) hexagonal prism high-entropy coordination molecular cage based on Au (III) is synthesized by using a hydrothermal method, and the unique arrangement mode of the (metal) ligands in the cage inhibits pi-pi stacking of a porphyrin photosensitizer, so that the effect of PDT is improved.

The invention relates to a cationic biomass-based nano enzyme as well as a preparation method and application thereof. The cationic biomass-based nano-enzyme comprises a biomass-based nano-enzyme and an electropositive substance for modifying the biomass-based nano-enzyme, and the biomass-based nano-enzyme comprises a tea seed cake extract, fulvic acid and a metal salt. The cationic biomass-based nano-enzyme can enhance the stress resistance and activity of microbial flora, and the preparation method is green, environment-friendly, simple and convenient.

The present invention relates to the technical field of special gas purification, and specifically discloses a porous adsorption material for removing neon from helium and a preparation method thereof. The method comprises the following steps: (1) preparing a lignin raw material treated by fermentation; (2) preparing a carbon precursor; (3) placing the carbon precursor in a mixed solution containing a metal salt and a surfactant, stirring and impregnating to obtain a carbon precursor impregnated with the metal salt; (4) washing the carbon precursor impregnated with the metal salt to remove the excessively deposited metal salt, and drying to obtain a washed carbon precursor; (5) activating and creating pores in the washed carbon precursor with carbon dioxide at a high temperature to obtain a porous adsorption material for removing neon from helium. The porous carbon adsorption material prepared by the present invention using renewable natural biomass raw materials has a uniformly distributed pore structure and has a high adsorption and capture ability for neon under low-temperature conditions, and can effectively remove neon impurities in helium.

The invention relates to the technical field of membrane separation and seawater desalination, in particular to a high-boron-removal-rate reverse osmosis membrane and a preparation method and application thereof. The polyamide reverse osmosis membrane with at least 70% nodular areas on the surface is prepared by introducing the ethylenediamine tetraacetic acid metal salt into the water phase solution as a complexing additive, and the boron removal rate of the membrane can be improved on the basis of ensuring the retention rate and flux of the membrane.

The invention relates to an elementary substance / alloy-metal oxyhydroxide anchored noble metal single atom / cluster heterojunction catalyst. A preparation method comprises the following steps: 1) dissolving a metal salt A, urea and ammonium fluoride in deionized water to obtain a mixed solution B; 2) performing hydrothermal reaction on the mixed solution B and a carrier to obtain a primary sample 1; 3) performing high-temperature calcination on the primary sample 1 in a mixed atmosphere of hydrogen and argon to obtain a primary sample 2; and 4) putting the preliminary sample 2 into a noble metal compound C solution for vacuum impregnation, taking out the sample after impregnation, and drying to obtain the catalyst. According to the scheme, the metal salt A is used as a metal source of a simple substance / alloy, the metal salt A is subjected to hydro-thermal synthesis to form a metal hydroxide and then subjected to high-temperature calcination reduction, the metal salt A is calcined to form the simple substance / alloy, then the simple substance / alloy is soaked in the precious metal compound solution C to form a metal oxyhydroxide, and meanwhile precious metal single atoms / clusters are anchored; the prepared catalyst is high in activity, and the preparation method is simple.

The invention discloses a graphene heat dissipation film with high vertical thermal conductivity and a preparation method thereof. The preparation method comprises the following steps: preparing graphene oxide slurry containing metal salt into a first graphene oxide wet film through a film forming process; adding and forming nanofibers on the first graphene oxide wet film to construct a vertical heat conduction path, and then adding the graphene oxide slurry to form a second graphene oxide wet film to form a multi-layer material; and carrying out drying, pre-oxidation treatment, vacuum carbonization treatment and graphitization treatment on the multi-layer material to obtain the graphitized film. The obtained graphene heat dissipation film is good in interface compatibility and small in interface thermal resistance, the heat conduction performance in the vertical direction is remarkably improved, and the excellent heat conduction performance can still be kept in the plane direction.

The invention discloses pre-activated-carbonized lignin-based hard carbon as well as a preparation method and application thereof. According to the method, alkali lignin is used as a carbon source, o-benzene nitrogen-containing metal salt is used as an activating agent, and the lignin-based hard carbon with large interlayer spacing and rich closed pores is prepared through pre-activation-carbonization. The preparation method comprises the following steps: firstly, carrying out oxidation modification on alkali lignin, mixing with o-benzene nitrogen-containing metal salt, and carbonizing to obtain pre-activated carbon; and washing and drying the pre-activated carbon, and performing secondary high-temperature carbonization to obtain the lignin-based hard carbon material. According to the lignin-based hard carbon material prepared through the method, the interlayer spacing is 0.385-0.397 nm, the closed pore volume is 0.54-0.73 cm < 3 > / g, the first-circle charging specific capacity is 361 mAh / g, the platform capacity is 242 mAh / g, sodium ion transmission is promoted, sufficient sites are provided for sodium cluster filling, and the lignin-based hard carbon material serves as a sodium ion battery negative electrode material and has high platform capacity and good rate capability.

The present invention discloses a layered metal hydroxide composite catalytic material, its preparation method and application. The composite catalytic material comprises a carrier carbon nanotube and a metal hydroxide loaded on the carbon nanotube, and the metal is iron, cobalt and nickel. Preparation method: (1) Dissolve nickel salt, cobalt salt, iron salt and urea in an alcohol solution, stir evenly, then add carbon nanotubes, and continue to stir evenly to obtain a mixed solution; (2) Carry out a solvothermal synthesis reaction on the mixed solution obtained in step (1), filter, wash and dry after the reaction is completed to obtain the layered metal hydroxide composite catalytic material. The carbon nanotubes are introduced into the layered metal hydroxide in this composite catalytic material, reducing the precipitation of metal ions, avoiding the aggregation of hydroxides, improving the stability and catalytic activity of the catalytic material, and being used for activating persulfate to degrade organic pollutants, realizing the efficient activation of persulfate so as to improve the degradation rate of pollutants.