137 results about "Bimetallic nanoparticle" patented technology

The invention relates to a method for preparing a carbon supported Au-Pt or Au-Pd catalyst by modifying Au-Pt or Au-Pd bimetal nanoparticles with microwaves, belonging to the technical field of catalytic materials. High pressure and high temperature generated by microwaves in a high-pressure reaction tank are utilized to treat an Au-Pt or Au-Pd composite nano colloid synthesized by a chemical coreduction method so as to induce the modification of the Au-Pt or Au-Pd bimetal nanoparticles; and the microwave-modified bimetal nanoparticles are deposited on the surface of the carbon support, thereby obtaining the carbon supported Au-Pt or Au-Pd catalyst with high activity. The carbon supported Au-Pt or Au-Pd catalyst has high electrocatalytic activity; the supporting rate of the Au-Pt or Au-Pd bimetal is high; the supporting amount of the Au-Pt or Au-Pd is controllable; and the method can be used for preparing the carbon supported Au-Pt or Au-Pd nano catalyst of which the mass ratio of Au-Pt or Au-Pd to carbon is 1-20%. The method provided by the invention has the advantages of low cost, simple technique and low facility request, and has wide industrial application prospects.

The invention relates to a preparation method and application of an electrochemical sensor for detection of heavy metal lead contaminants and belongs to the technical field of electrochemical detection. The preparation method is characterized by including; performing synthesis to obtain a Fe-MOFs nano material, reducing palladium-platinum bimetallic nanoparticles onto the Fe-MOFs nano material, and mixing a hairpin type DNA signal probe with the composite material to obtain a biological signal probe; performing layer-by-layer self-assembly through rGO-TEPA and avidin for fixing of '8-17'DNAzyme to obtain the electrochemical sensor for detection of the heavy metal lead contaminants. The sensor is successfully applied to detection of lead contaminants in the environment. The preparation method and application has the advantages of high flexibility, high specificity and rapid and convenient detection; experimental evidence is provided for research of lead contamination detection technology, and new concepts and new technology platforms are provided for monitoring the lead contaminants in the environment are provided.

The invention relates to graphene-loaded double-metal nano particles for methanol and ethanol fuel cells, and a preparation method for the graphene-loaded double-metal nano particles. The method comprises the following steps of: sequentially adding graphene oxide, polymeric dispersant, and anionic surfactant into a water-ethanol mixed solution, stirring, adding double-metal nano particles, and adding sodium borohydride to obtain black precipitate double-metal nano particle graphene; and performing centrifugal separation on precipitate by using a centrifugal machine, repeatedly washing by using secondary deionized water and ethanol to remove unreacted reactant, and then performing vacuum drying. According to the method, gold and silver which is low in price, and non-noble metal such as cobalt and nickel which is lower in price is used instead of noble metal such as platinum and ruthenium which is high in price, so cost is reduced. Methanol is catalyzed and ethanol is oxidized under thealkaline condition, so the condition that intermediate carbon monoxide poisons a catalyst under the acid condition so that the activity of the catalyst is reduced can be effectively overcome. The graphene-loaded double-metal nano particles can be directly used for methanol and ethanol fuel cells, formic acid fuel cells, and organic catalytic reaction.

The invention discloses a hydro-thermal synthetic method and application of Pt-Ru bimetal nanoparticles. The method includes: dissolving precursor platinum salt and precursor ruthenium salt in water, adding polyvinylpyrrolidone and formaldehyde prior to mixing, placing mixture in a sealed container, and heating the container to 150 to 170 DEG C to allow 4 to 8 hours of reduction reaction so as to obtain the Pt-Ru bimetal nanoparticles. The Pt-Ru bimetal nanoparticles can serve as a good catalyst for low-temperature (130 to 170 DEG C) aqueous-phase Fischer-Tropsch synthesis, with catalytic activity superior to Ru nanoparticles made by methods such as H2 reduction and NaBH4 reduction and far superior to Fe and Co nanoparticles.

The invention discloses a method for directly synthesizing Pt-Co bimetallic nanoparticles utilizing a water phase and application thereof. The method comprises the following steps of: dissolving a platinum precursor salt and cobalt (II) acetylacetonate hydrate in water, and simultaneously adding polyvinylpyrrolidone to mix; and then placing a mixture in a sealed container, filling 1-3 MPa hydrogen, heating to 60-100 DEG C, and carrying out reduction reaction for 4-8 hours to obtain the Pt-Co bimetallic nanoparticles. The Pt-Co bimetallic nanoparticles are isolated through a magnetic field action so as to be used as a good catalyst for low-temperature water-phase Fischer-Tropsch synthesis, and the catalytic activity of the catalyst is greatly superior to that of the traditionally synthesized alloyed Pt-Co nanoparticles and the Pt-Co nanoparticles of a core-shell structure.

The invention provides a dopamine electrochemical sensing electrode based on double-metal nanoparticle doped vanadium-containing heteropoly acid / carbon nanotubes, belongs to the technical field of electrochemical sensors and particularly relates to the dopamine electrochemical sensing electrode, aiming at solving the problems of an existing electrochemical sensor for detecting dopamine that the linear range is narrow, the detection limit is high and the responding time is slow. The dopamine electrochemical sensing electrode based on the double-metal nanoparticle doped vanadium-containing heteropoly acid / carbon nanotubes is prepared from an ITO (Indium Tin Oxide) electrode, a polyethyleneimine layer and a double-metal nanoparticle doped vanadium-containing heteropoly acid layer and a carbon nanotube layer; a polyethyleneimine layer / double-metal nanoparticle doped vanadium-containing heteropoly acid layer / polyethyleneimine layer / carbon nanotube layer is used as a circulating unit; and the circulating unit is circulated for n times. The dopamine electrochemical sensing electrode based on the double-metal nanoparticle doped vanadium-containing heteropoly acid / carbon nanotubes can be obtained by the invention.

The invention discloses a preparation method of a Ru-Ni bimetallic based ordered mesoporous carbon catalyst. The method is as below: reacting a template CTAB, a silicon source TEOS, a carbon source of 8-hydroxy quinoline modified chitosan and metal precursors of nickel salt and ruthenium salt under alkaline condition in an ethanol-water medium at room temperature, and conducting hydro-thermal treatment to obtain a cubic mesoscopic compound with uniformly dispersed metal chitosan complex; and then directly carbonizingat high temperature to remove the template, carbonize the chitosan and reduce Ru and Ni metal ions; and finally removing silica to obtain in situ ordered mesoporous carbon supported Ru-Ni bimetallic nanoparticle catalyst. The method provided by the invention has the advantages of economical steps, low cost, easy operation method and good universality, can simultaneously realize carrier ordering, dispersion of active components and the modulation and control of components, so as to obtain efficient bimetallic catalyst for levulinic acid hydrogenation.

The invention discloses a two-dimensional nanosheet composite photocatalyst with bimetallic nanoparticles as heterojunctions. The two-dimensional nanosheet composite photocatalyst is composed of a photocatalytic active component and the bimetallic nanoparticles uniformly distributed on the photocatalytic active component by virtue of a binding agent, wherein the photocatalytic active component is a two-dimensional g-C3N4 nanosheet, the binding agent is 0.1-5wt% Nafion perfluorinated resin solution, and the bimetallic nanoparticles are Pd-Ag bimetallic nanoparticles. Raw materials used by the composite photocatalyst are environment-friendly materials respectively, and the Pd-Ag bimetallic nanoparticle heterojunctions have surface plasma resonance effect and interface schottky effect and can more effectively utilize visible light and inhibit recombination of photo-induced electrons and holes, so that the composite photocatalyst disclosed by the invention has high activity and good stability when being applied to hydrogen production through photocatalytic decomposition of water.

The invention discloses a layered composite photocatalyst using bimetallic nanoparticles as heterojunctions. The composite photocatalyst consists of a photocatalysis active component and bimetallic nanoparticles, wherein the bimetallic nanoparticles are uniformly distributed on the photocatalysis active component through an adhesive; the photocatalysis active component is Ti3C2 with a layered structure or an oxidizing product TiO2-xCx, and the adhesive is 0.1-5wt% Nafion perfluorination resin solution, preferably 0.5wt%; the weight percentage of bimetallic nanoparticles and photocatalysis active component is 0.01 to 10.0%; the weight percentage of adhesive and photocatalysis active component is 0.01 to 5.0%. Compared with the prior art, the composite photocatalyst has the advantages that the visible light is more effectively utilized, and the compounding of photo-induced electrons and cavities is inhibited; when the composite photocatalyst is used for photocatalyzing to decompose water to produce hydrogen, the activity is high, and the stability is good.

The invention discloses a monatomic palladium-cobalt bimetallic nano-catalyst for efficiently catalyzing benzene oxidation, and belongs to the technical field of functional materials, wherein PdCo bimetallic nanoparticles are loaded onto a gamma-Al2O3 carrier, firing is performed to form a Pd1Co1 / Al2O3 catalyst, and the loading capacity of the metal palladium is 0.4 wt%. The preparation method comprises: in a dichlorobenzene system, simultaneously pyrolyzing and reducing palladium acetylacetonate and octacarbonyldicobalt by adopting an oil-phase one-step pyrolysis method to form PdCo bimetallic particles with uniform size, and loading the metal particles onto an Al2O3 carrier by adopting an impregnation method, wherein the Pd loading capacity is 0.4 wt%; and carrying out hydrothermal roasting on the supported catalyst at a temperature of 800 DEG C to form the Pd1Co1 / Al2O3 nano-catalyst. The Pd1Co1 / Al2O3 nano-catalyst prepared by the method is simple in preparation process, the double metals are in monatomic dispersion, and the Pd1Co1 / Al2O3 nano-catalyst has good application prospect in the field of catalysis.

The invention relates to a magnetic graphene-based platinum-nickel bimetallic catalyst and a preparation method of the magnetic graphene-based platinum-nickel bimetallic catalyst. Platinum-nickel alloy type bimetallic nanoparticles with the particle size being 10-20nm are loaded on a graphene carrier, the saturation magnetization of the catalyst at 15-35 DEG C is 8-13emu / g, and the bimetallic catalyst is prepared from the following ingredients by weight percent: 75-85wt% of graphene, 1.5-3.6wt% of platinum and 12.8-22.5wt% of nickel, and the sum of all percentages of all ingredients is 100%. The preparation method comprises the steps of preparing graphene oxide-tannic acid composite aqueous solution; adding nickel metallic ion solution to adjust the pH value to be 9-10, adding reducing agents and stirring for reaction, washing until the pH value of the supernatant liquid is 6.5-7, and taking precipitates at the lower layer to obtain the magnetic graphene-based platinum-nickel bimetallic catalyst. The magnetic graphene-based platinum-nickel bimetallic catalyst can be separated out of a reaction system thoroughly under an external magnetic field, and the recovery process is simple and efficient.

The invention relates to a mesoporous platinum-palladium bimetallic nanoparticle and a preparation method thereof. The particle size of the mesoporous platinum-palladium bimetallic nanoparticle is 30-100nm, and the surface of the nanoparticle has a porous structure whose aperture is uniform, and the aperture is 2-3nm. The preparation method is as follows: (1) sodium tetrachloropalladate, chloroplatinic acid and a surfactant are dissolved in water, the materials are stirred uniformly at 30-90 DEG C, and a mixed solution containing bimetal is obtained; (2) a reducing agent solution is added into the mixed solution containing bimetal obtained in the step (1), a reaction is continued to carry out for 2-5 hours, an obtained reaction solution is centrifugal and separated, and the mesoporous platinum-palladium bimetallic nanoparticle is obtained by post-treatment. The invention provides a simple method for synthesis of the mesoporous precious metal nanoparticle with simple process and short synthesis period; the synthesized mesoporous precious metal nanoparticle is used as a catalyst for an industrial nitrobenzene hydrogenation reaction with very high activity.

The invention provides a method for revealing a nano bi-metal CoNi adsorption mechanism based on the density functional theory and belongs to the technical field of chemical engineering. A nano adsorbent is prepared through simple reduction reaction under the room-temperature air, and the efficient adsorption mechanism of the adsorbent is deeply analyzed by applying a computer simulation auxiliary adsorption experiment result based on the density functional theory. The method comprises the following steps that 1, CoNi bi-metal nano particles are prepared; 2, the adsorption performance of the CoNi bi-metal nano particles is tested; 3, a CoNi bi-metal surface model is constructed; and 4, the surface property of the CoNi bi-metal surface model is calculated. According to the method for revealing the nano bi-metal CoNi adsorption mechanism based on the density functional theory, the method that density functional theory calculation and the experiment result are combined is adopted to illustrate that the adsorption performance of the CoNi bi-metal nano particles is superior to that of single metal (Co or Ni) on the molecule and atom level, and the efficient adsorption mechanism of the CoNi bi-metal nano particles is revealed by analyzing the surface energy, the work function, the state density, the surface atomic charge difference density and the d belt center of the surface model.

The invention relates to a temperature sensitive graphene-based gold-platinum core-shell bimetallic catalyst and a preparation method thereof. The catalyst is characterized in that a gold-platinum core-shell structured bimetallic nanoparticle with the particle size of 35-50nm is supported on a graphene carrier as an active site, sulfhydrylated polyisopropyl acrylamide grafted glucan is coated on the gold-platinum core-shell structured bimetallic nanoparticle as a temperature stimulation response factor, the catalyst concretely comprises 28-42.5wt% of graphene, 2.4-9wt% of gold, 2.4-9wt% of platinum, and 50-60wt% of the sulfhydrylated polyisopropyl acrylamide grafted glucan, and the sum mass percentages of all components is 100%. The method comprises the following steps: preparing a temperature sensitive graphene-based gold-platinum core-shell bimetallic catalyst precursor; preparing an aqueous solution of polyisopropyl acrylamide grafted glucan; and preparing the temperature sensitive graphene-based gold-platinum core-shell bimetallic catalyst. The catalyst has the advantages of high catalysis activity, good reusability, and realization of temperature control of the catalysis activity.

The invention relates to a PVDF (Polyvinylidene Fluoride) / Fe-Pd bi-metal nanoparticle hybrid membrane and a preparation method thereof. The preparation method comprises the steps of blending polymer microspheres and PVDF to prepare a membrane, and then, loading ferrum-palladium bi-metal nanoparticles to prepare the hybrid membrane with favorable catalytic reaction activity and separation performance. By using the PVDF / Fe-Pd bi-metal nanoparticle hybrid membrane, chlorine-contained organisms such as trichloro ethylene, monochloroacetic acid, dichlorinated biphenyl, dichlorphenoxyacetic acid and the like can be subjected to reductive dechlorination reaction, and chlorine atoms in the chlorine-contained organisms are converted into hydrogen atoms. In addition, the membrane can also be used for the catalytic reduction reaction of nitro in nitrobenzene molecules such as aminonitrobenzene, nitrobenzene, methylnitrobenzene and the like so as to convert the nitro into an amino group.

The invention discloses a hollow bimetal nanoparticle / titanium dioxide core-shell structure. Hollow bimetal nanoparticles are used as the core, titanium dioxide is used as the shell, and a gap is arranged between the hollow bimetal nanoparticles and titanium dioxide. The invention also discloses a preparation method of the core-shell structure and application of the core-shell structure in photocatalytic degradation of organic matters. The preparation method comprises the following steps: by using an amphiphilic block copolymer micelle as a reactor, preparing copolymer-coated nanoparticles, preparing hollow-structure bimetal nanoparticles by using the nanoparticles as a sacrifice template, coating titanium dioxide on the hollow-structure bimetal nanoparticles by a sol-gel process, and removing the block copolymer to obtain the product. The method implements uniform dispersion of the hollow-structure bimetal nanoparticles in the titanium dioxide, prevents the hollow-structure bimetal nanoparticles from accumulation, increases the interfacial area between the noble metal nanoparticles and titanium dioxide material, and obviously enhances the catalytic activity for ultraviolet degradation of organic matters.

The invention relates to a preparation method of a palladium-lead bimetallic catalyst with an eggshell structure. The method comprises the following steps: introducing a Pb species into an aluminum oxide carrier by adopting a method of firstly loading a Pb precursor and improving the loading amount of Pb, and then performing liquid phase reduction to prepare the Pd-Pb bimetallic catalyst, wherein Pd-Pb bimetallic nanoparticles in the obtained catalyst are distributed in an eggshell region at 20 mu m below the outer surface of the aluminum oxide carrier. The catalyst has high catalytic activity, product selectivity and stability in reaction for preparing methyl methacrylate (MMA) by alcohol aldehyde one-step oxidative esterification. Compared with the traditional Pd-Pb bimetallic catalyst, the novel Pd-Pb bimetallic catalyst with the eggshell structure has the advantages of simple preparation method, high Pd dispersion degree, easiness in control of composition of the catalyst and the like, so that the loading amount of the precious metal Pd can be reduced by about 150%, and the investment cost of the catalyst is significantly reduced.

The invention discloses a bimetal / carbon layered composite sphere and a simple and quick preparation method for the same. The preparation method is based on merits of microwave heating, and includes that mixed liquor containing metal ions {including positive ions such as [Ag(NH<3>)<2>]<+>, Pd<2+> and Au<+> and negative ions such as MCl<n>(wherein the M represents Au, Pd and Pt)} with different electric charges is used as a precursor, and different types of metal selectively are grown inside and outside a carbon sphere simultaneously, so that the bimetal carbon-doped layered composite sphere with nano-particles can be prepared. The bimetal / carbon layered composite sphere and the preparation method have the advantages that an integral preparation procedure only takes 2-10 minutes, and reaction parameters are adjusted, so that the sizes, the number density and the positions of the metal nano-particles can be controlled; the shortcoming of difficulty in growing more than two types of metal nano-particles inside a preliminarily prepared carbon sphere can be overcome, and the constraint that usually only alloy can be generated via co-reduction of mixed metal ions under the condition of traditional heating is broken through; devices applied in the preparation method are simple, operation is easy, the controllability is good, and the preparation method can be particularly popularized to controllable preparation for other bimetal doped multilayer composite materials with nano-particles.

The invention discloses a montmorillonite-loaded nano Pd / Cu catalyst and in-situ one-pot preparation and application thereof. The catalyst is prepared by taking montmorillonite as a carrier by taking absolute ethyl alcohol as a solvent and a reducing agent, and by adopting an in-situ one-pot method in one step under solvothermal conditions. The preparation and after-treatment of the catalyst are simple in steps, any surfactant is not needed to be added, the reaction system is green and environment-friendly, the problem that bimetallic nanoparticles are difficultly obtained in a solvent system is solved, and the shape, size and metal ratio of the catalyst are effectively controlled. The prepared catalyst can be used for efficiently catalyzing a Sonogashira cross-coupling reaction of aryl iodides and aryl terminal alkyne or alkyl terminal alkyne under a mild condition, the amount of the catalyst is small, the yield of the target product is high, and the catalyst can be applied to construction of Csp-Csp2 bond structures.

The invention relates to a preparation method of an electrochemical DNA biosensor for detection of LPL gene SNP (rs1801177), and belongs to the technical field of electrochemical detection. The preparation method is characterized by comprising the steps: firstly, the surface of a nitrogen-doped graphene (N-G) sheet is loaded with a large number of palladium-platinum bimetal (PdPt) nanoparticles, then polyaniline is formed on the surface of the nitrogen-doped graphene (N-G) sheet by in-situ polymerization to obtain a nano composite material, next, a single-stranded DNA signal probe is mixed with the composite material, and a redox probe is prepared; secondly, a capture probe is immobilized on the surface of a sensor by a C60 / PAMAM / Au nanocomposite material, and the electrochemical DNA biosensor for quantitative detection of rs1801177 is prepared. The biosensor is successfully applied to detection of single-base mutation of a lipoprotein lipase gene. The biosensor has the advantages of high sensitivity, strong specificity, and convenient and fast detection, provides a new method for detection of rs1801177, and provides a theoretical basis and an experimental basis for clinical diagnosis and prevention of cardiovascular diseases.

The invention belongs to the technical field of photochemistry organic synthesis, and particularly relates to a method for preparing a benzimidazole compound through a supported bimetallic catalyst at room temperature .The preparation method of the benzimidazole compound comprises the steps that o-phenylenediamine and reactant alcohol are used as initial reactants, a photocatalyst is used as a supported bimetallic nanoparticles, in an organic solvent and under the stirring condition and irradiation of ultraviolet light or visible light or sunlight, the o-phenylenediamine and the reactant alcohol are directly subjected to photocatalysis through light source irradiation to be converted into benzimidazole and a derivative thereof .According to the method, reaction conditions are mild, high-temperature reaction conditions are not needed, the reaction speed at room temperature is high, and the selectivity of the target product benzimidazole is 95% or above .

The invention discloses a platinum-ruthenium bimetal loaded zirconia nanotube composite material and a preparation method thereof and application in a thermocatalytic treatment of toluene. A SBA-15-OHmolecular sieve is taken as a template, zirconium oxychloride octahydrate is taken as a metal precursor, and a zirconia nanotube material is prepared through aging, calcination and etching; a certainamount of zirconia is taken as a carrier, and a certain amount of metal precursors such as chloroplatinic acid and ruthenium trichloride are added, and through ultrasonic stirring, a solvent is stirred for thermal evaporation and hydrogen reduction calcination is carried out to obtain a certain proportion of the platinum-ruthenium bimetal loaded zirconia nanotube composite material. The platinum-ruthenium bimetal loaded zirconia nanotube composite material synthesized through a series of steps has a good thermal catalytic effect on toluene gas, complete catalysis of low-concentration tolueneat a lower temperature can be achieved, and great research significance and certain application prospects for solving the toluene pollution gas in the air environment are achieved

The invention provides a novel method for preparing silver-rhodium nanoparticles and belongs to the technical field of nano synthesis methods. Graphene quantum dots are utilized to prepare the silver-rhodium bimetallic nanoparticles, the operation is simple, reaction conditions are mild, and the prepared bimetallic nanoparticles are very stable, small in particle size and good in monodispersity performance, wherein the particles size of the nanoparticles is just a few nanometers. The prepared silver-rhodium bimetallic nanoparticles have better catalytic performance than silver nanoparticles and rhodium nanoparticles. The stable bimetallic nanoparticles are prepared by using an aqueous solution of the graphene quantum dots first and then adding a sodium borohydride aqueous solution and a mixed aqueous solution of silver nitrate and rhodium nitrate. The prepared bimetallic nanoparticles are dispersed in a clear and transparent solution.

The invention relates to a method for preparing cis-pinane by catalyzing a hydrogenation reaction of alpha-pinene under the mild condition by taking palladium-nickel bimetallic nanoparticles with stable polyethylene oxide-polypropylene oxide-polyethylene oxide three-block copolymer (P123) micelle as a catalyst, and belongs to the field of catalyst preparation and application. According to the method for catalyzing the hydrogenation reaction of alpha-pinene by means of the palladium-nickel bimetallic catalyst in an aqueous medium, reacting under stirring is conducted for 3 h under the conditions of 0.7 MPa H2 and 50 DEG C, the conversion rate of alpha-pinene can reach 99.8%, and the selectivity of cis-pinane is 96.3%. The method is easy and convenient to operate and friendly to environment; especially, the bimetallic catalyst is adopted, the dosage of noble metal palladium is decreased, the catalyst cost is reduced, and the selectivity of cis-pinane is improved. An environment-friendly novel way is provided for selective preparation of cis-pinane.

The invention discloses a method for treatment of hexavalent chromium water with modified iron-copper bimetallic nanoparticles. The method includes the steps of: mixing the modified iron-copper bimetallic nanoparticles with hexavalent chromium water, and performing constant temperature treatment to complete treatment of hexavalent chromium water. Specifically, the modified iron-copper bimetallic nanoparticles include chitosan and iron-copper bimetallic nanoparticles, and the chitosan is coated on the surfaces of iron-copper bimetallic nanoparticles. The method for treatment of hexavalent chromium water with modified iron-copper bimetallic nanoparticles provided by the invention has the advantages of simple operation, low cost, short treatment period, high reaction efficiency and the like,can treat high concentration Cr (VI) polluted underground water, also has a wide pH application range, thus being a novel restoration method that has good application prospects and can effectively remove Cr (VI) from underground water.

The invention discloses a preparation method of gold-platinum (Au@Pt) bimetallic nanoparticles. The preparation method comprises the steps of enabling a chlorogenic acid aqueous solution to react witha chloroplatinic acid aqueous solution and a chloroauric acid aqueous solution at 80-100 DEG C, and obtaining the gold-platinum bimetallic nanoparticles. The green preparation method of the Au@Pt bimetallic nanoparticles is efficient and rapid. The preparation method adopts biologically active chlorogenic acid as a reducing agent and avoids the use of reducing agents with higher toxicity such assodium borohydride and the like. The preparation method does not need additional stabilizers or protective agents, and is simple and environmental-friendly in reaction conditions and short in reactiontime. The prepared Au@Pt bimetallic nanoparticles have good dispersibility, good scavenging effect on DPPH free radicals, good oxidation resistance and potential medical applicability.

The invention discloses a salicylic acid surface modified nano TiO2 magnetic composite material and a preparation method. The method includes: preparing Fe / Ni bimetallic nanoparticles by co-reduction deposition technique; coating Fe / Ni magnetic cores directly with an SiO2 gel precursor by direct coating technique; taking SiO2@Fe / Ni as the template, using sol-gel technique and a surface modification technology to synthesize the salicylic acid surface modified magnetic bimetallic / SiO2 / TiO2 core-shell nano composite photocatalytic new material. According to the invention, Fe / Ni is taken as the magnetic core, and is coated with SiO2 and TiO2 layer by layer, finally through surface modification, the TiO2 nano material can achieve magnetic recovery, the specific surface area is increased, the surface hydroxyl and other groups are increased to be conducive to adsorption, visible light response is realized through surface modification, at the same time Fe / Ni inhibits electron-hole pair compounding, thus synergetically enhancing visible light photocatalysis and adsorption capacity.

The invention discloses an HMS@NiPt@Beta core-shell structure catalytic material and a preparation method and application thereof. According to the catalytic material, a microporous Beta molecular sieve serves as a core, a mesoporous HMS molecular sieve serves as a shell, NiPt bimetallic nanoparticles are evenly distributed on the surface of the microporous Beta molecular sieve, the core of the microporous Beta molecular sieve is prepared through a hydrothermal synthesis method, niPt bimetallic nanoparticles are loaded on the surface of the microporous Beta molecular sieve through a low-temperature oxygen plasma treatment technology, the mesoporous HMS molecular sieve shell is prepared through a vapor phase crystal transformation method, and based on the total mass of the catalytic material, nickel accounts for 10-30 wt%, platinum accounts for 0.01-5 wt%, the microporous Beta molecular sieve core accounts for 40-60 wt%, and the balance is the mesoporous HMS molecular sieve shell. The catalytic material is applied to a reaction for catalyzing dehydrogenation coupling of pyridine to synthesize 2, 2'-dipyridyl, has the advantages of low dosage, few side reactions, short process and the like, and has a good application prospect in the fields of adsorption separation, petrochemical engineering, fine chemical production and the like.

The invention provides a multi-branched gold and silver composite nanomaterial having excellent surface enhanced Raman scattering characteristics and a preparation method thereof. The multi-branched gold and silver composite nanomaterial comprises the steps of dissolving silver nitrate and polysorbates 80 in deionized water, and performing ultrasonic dispersion; adding gold, and obtaining Ag@Au bimetallic nanoparticles through laser irradiation, centrifugation and drying; causing the obtained Ag@Au bimetallic nanoparticles to undergo ultrasonic dispersion into the deionized water, adding chloroauric acid aqueous solution and ascorbic acid aqueous solution, reacting for 2-3 min at indoor temperature, and obtaining initial multi-branched Ag@Au composite nanomaterial dispersion liquid; mixing the obtained dispersion liquid and ethanol solution of silver nitrate, and obtaining the multi-branched gold and silver composite nanomaterial through laser radiation, centrifugation, washing and drying. The preparation method is simple, controllable, green, environmentally friendly and low in cost, and the obtained composite nanomaterial is small in size (-50 nm) and has excellent performances in the aspect of surface enhanced Raman scattering.