164 results about "Palladium nanoparticles" patented technology

The invention discloses a flexible hydrogen sensor and a manufacturing method thereof, and the flexible hydrogen sensor comprises a flexible substrate which is made of a polyimide material; the gas sensitive layer is printed on the flexible substrate, and the gas sensitive layer is a graphene layer loaded with palladium nanoparticles and silver nanoparticles; the electrode layer is deposited on the gas sensitive layer; and the protective layer is formed on one side, deviating from the flexible substrate, of the electrode layer and the gas sensitive layer. The flexible hydrogen sensor can be flexibly installed in a new energy power battery pack, and hydrogen generated when the battery fails is sensitively detected.

The invention belongs to a photocatalysis technology, and particularly relates to a palladium-loaded gallium nitride nanowire photocatalyst as well as a preparation method and application thereof, and the palladium-loaded gallium nitride nanowire photocatalyst comprises a silicon substrate, a gallium nitride nanowire vertically grown on the silicon substrate and palladium nanoparticles uniformly loaded on the surface of the gallium nitride nanowire. Compared with the prior art, the problem that in the prior art, natural seawater cannot be used for photocatalytic decomposition for hydrogen and hydrogen peroxide is solved. According to the scheme, the limitation is solved by introducing the palladium-modified gallium nitride nanowire: the palladium nanoparticles serve as an efficient hole extractor, so that the adsorption of hydroxyl (* OH) is reduced, and the generation of hydrogen and hydrogen peroxide is accelerated; chloride ions in seawater further improve the catalytic performance by improving charge kinetics and reducing the energy barrier of the reaction.

A method of carbon dioxide fixation includes contacting a covalent organic framework material with a co-catalyst and an epoxide in the presence of carbon dioxide to form a cyclic carbonate. The covalent organic framework material includes reacted units of a 2,4,6-trimethyl-1,3,5-triazine, reacted units of a 4,4′-biphenyldicarbaldehyde, and palladium nanoparticles. The reacted units of the 2,4,6-trimethyl-1,3,5-triazine and the reacted units of the 4,4′-biphenyldicarbaldehyde form a COF-701, where the palladium nanoparticles are on an outer surface of the COF-701. The co-catalyst is n-tetrabutylammonium bromide.

The invention belongs to the technical field of pollutant treatment, and particularly relates to a method for treating a pollutant BDE-47 through electro-catalysis. According to the invention, BDE-47 is firstly dispersed in an emulsion system, so that the oil-water interface area is enlarged, and the mass transfer efficiency is improved; furthermore, the oil-water interface tension is reduced through polydopamine modified multi-walled carbon nanotubes, and palladium nanoparticles are loaded on the polydopamine modified multi-walled carbon nanotubes, so that the generation of oil-water interface electrocatalytic active hydrogen is realized. According to the invention, the palladium nanoparticle-loaded polydopamine modified multi-walled carbon nanotube is an emulsification-catalysis integrated catalyst, so that the synergistic regulation of catalytic activity and interfacial affinity can be realized, and the electrocatalytic degradation conversion efficiency of BDE-47 is improved.

The invention relates to a method for preparing a molecular sieve confinement active metal catalyst and application of the catalyst. According to the preparation method of the molecular sieve confinement active metal catalyst, a traditional organic structure directing agent is replaced with a seed crystal method, and a metal-molecular sieve catalyst is prepared in an in-situ confinement mode by directly adding molecular sieve seed crystals into a metal silicon-aluminum sol precursor. The metal-coated molecular sieve prepared by the method has metal species with smaller size, the synthesis method is simple and convenient, the use of an organic structure-directing agent is saved, and the cost of the catalyst is reduced. The metal scale of the metal-at-molecular sieve is monatomic, sub-nano, and nano-scale. The sub-nano palladium-coated molecular sieve catalyst is applied to catalysis of semi-hydrogenation reaction of phenylacetylene, has excellent catalytic performance, and shows accurate catalytic selectivity on alkyne molecules less than # imgabs0 #.

The application belongs to the technical field of sensitive materials, and discloses a high-performance TiO2@In2O3 / Pd sensitive film for a MEMS gas sensor, a synthesis method thereof and a MEMS gas sensor. The method comprises the following steps: synthesizing mesoporous TiO2 nanoparticle balls; mixing indium salt, an alkaline compound, a surfactant and the mesoporous TiO2 nanoparticle balls uniformly, and then performing hydrothermal reaction; centrifuging, washing and drying the product of the hydrothermal reaction, and then performing first annealing treatment in an air atmosphere to obtain In2O3-coated titanium dioxide nanoparticle balls TiO2@In2O3; modifying palladium nanoparticles to the nanoparticle balls TiO2@In2O3 by a solution method, centrifuging, washing and drying, and then performing second annealing treatment in a hydrogen atmosphere to obtain In2O3-coated titanium dioxide nanoparticle balls TiO2@In2O3 / Pd with Pd modification; and manufacturing the nanoparticle balls TiO2@In2O3 / Pd into a sensitive film. The sensitive film manufactured by the above method can improve the sensitivity of gas detection.

The invention discloses a Pd supported catalyst as well as a preparation method and application thereof, and belongs to the technical field of catalysts. The Pd supported catalyst is prepared according to the following steps: dissolving TEOS and MSDS in absolute ethyl alcohol, stirring, adjusting the pH value, aging at room temperature, and drying to obtain a mixture; and extruding the mixture into a long strip shape, calcining to prepare a TiO2-SiO2 composite carrier, dipping the TiO2-SiO2 composite carrier in a palladium nanoparticle solution, filtering, washing, and drying in vacuum to obtain the catalyst. The preparation method is simple and green in process, the reaction process is safe and easy to control, the prepared Pd supported catalyst is good in crystallization, high-dispersion nano-particle morphology, uniform in size and uniform in dispersion, and when the Pd supported catalyst is applied to co-production of methyl isobutyl ketone and methyl isoamyl ketone from mixed aldehyde and ketone, the isobutyraldehyde conversion rate can be effectively increased, and the yield of methyl isobutyl ketone and methyl isoamyl ketone can be effectively increased. The selectivity on methyl isoamyl ketone is good, and organic impurities in the product are few.

The invention belongs to the technical field of conductive materials, and particularly relates to a method for preparing and activating pyridine functionalized swelling polymer microspheres and a method for preparing core-shell structure polymer conductive microspheres. The preparation method comprises the following steps: by taking polystyrene microspheres as seeds, preparing pyridine functionalized polymer microspheres through an emulsion swelling method, then introducing Pd < 2 + > ions through coordination, preparing activated microspheres with palladium nanoparticles uniformly coated on the surfaces of the polymer microspheres through in-situ reduction, preparing nickel-plated microspheres with uniform metal coatings through chemical plating, and finally preparing the polymer microspheres with uniform metal coatings. And finally, preparing the core-shell structure gold-plated polymer conductive microspheres through in-situ reduction, and applying the core-shell structure gold-plated polymer conductive microspheres to preparation of anisotropic conductive films. Through an emulsion swelling method, not only can the polymer microspheres with adjustable sizes be prepared, but also the polymer microspheres with different morphologies can be prepared. The preparation method of the conductive microspheres has the advantages of being wide in raw material source, easy and convenient to operate and adjustable in metal coating thickness, and is suitable for high-precision packaging in the microelectronic industry.

The invention discloses a preparation method and application of a high-efficiency palladium catalyst for tandem ammonia borane dehydrogenation and nitro-aromatic hydrogenation reaction. The catalyst for the tandem ammonia borane dehydrogenation and nitro-aromatic hydrogenation reaction is a porous nitrogen-doped carbon material with palladium nanoparticles uniformly enriched in pore channels, the specific surface area of the catalyst is 120.18 m < 2 > / g, and the average pore size is 4-6 nm. The catalyst disclosed by the invention is applied to tandem ammonia borane dehydrogenation and nitro-aromatic hydrogenation reaction, water is used as a solvent in the reaction process, and the catalyst has the advantages of green synthesis, high activity, high selectivity and high stability.

The invention discloses a close-packed hexagonal-phase triangular-sheet-shaped nano-palladium catalyst and a preparation method thereof, and belongs to the technical field of nano-material preparation. According to the preparation method, palladium acetylacetonate is taken as a reactant, N, N-dimethylformamide is taken as a reaction solvent, hexadecyl trimethyl ammonium bromide is taken as a reducing agent and a crystal phase structure control agent, molybdenum hexacarbonyl is taken as a morphology control agent, and the close-packed hexagonal-phase triangular-sheet-shaped nano-palladium catalyst with regular morphology and controllable size is prepared through a simple liquid-phase thermochemical reduction method. The specific surface area of the two-dimensional sheet structure is large, the number of unsaturated atoms on the surface is large, interface charge transfer is fast, and improvement of the electro-catalytic performance is facilitated; and the triangular structure can provide more edge active sites, so that the catalytic activity can be further improved.

The invention provides a monatomic regulation and control chemiluminescence detection fluorine ion sensor, a preparation method and application, and relates to the technical field of chemiluminescence detection sensors, the monatomic regulation and control chemiluminescence detection fluorine ion sensor comprises a silicon dioxide coated monatomic copper-calcium oxide nanoparticle composite material, an F <->-containing aqueous solution reaction tank, a microwell plate and a chemiluminescence analyzer; dispersing the obtained palladium nanoparticle-calcium oxide nanoparticle composite material wrapped by silicon dioxide into F <->-containing aqueous solutions with different concentrations, heating to react for a set time, adding a proper amount of the mixed solution into a 96 microwell plate, putting the 96 microwell plate into a cassette of a chemiluminescence analyzer, adding a proper amount of luminol to initiate a reaction, and detecting the concentration of the palladium nanoparticle-calcium oxide nanoparticle composite material. The chemiluminescence intensity is recorded through a chemiluminescence analyzer, a working curve is drawn, and quantitative analysis of F <-> is achieved.

The application provides a preparation method of a metal-functionalized graphene film, and belongs to the technical field of nanofluid mass transfer. The preparation method comprises the following steps: firstly, dispersing a palladium precursor and graphene oxide in an alcohol solvent, and growing palladium nanoparticles on the surface of the graphene oxide in situ through first heating to obtain a first dispersion liquid comprising graphene oxide loaded with the palladium nanoparticles; then adding deionized water and a reducing agent to the first dispersion liquid, stirring and performing second heating, so that the graphene oxide in the first dispersion liquid is reduced to reduced graphene oxide to obtain a second dispersion liquid comprising reduced graphene oxide loaded with the palladium nanoparticles; and finally, preparing a film from the second dispersion liquid to obtain the metal-functionalized graphene film. In other aspects of the application, a metal-functionalized graphene film obtained by the aforementioned preparation method and an application of the metal-functionalized graphene film in an electrically controlled ion separation device are also provided.

The invention discloses a polyelectrolyte multilayer film loaded gold-palladium bimetallic nanoparticle catalyst, which is characterized in that cationic polyelectrolyte poly (diallyldimethylammonium chloride) PDDA and anionic polyelectrolyte sodium polystyrenesulfonate (PSS) are used as construction materials, a layer-by-layer self-assembly technology is adopted to prepare a polyelectrolyte multilayer film, and the polyelectrolyte multilayer film is marked as (PDDA / PSS) n + 0.5, and firstly loading gold nanoparticles on the multilayer film through an ion exchange-in-situ reduction method, and then loading palladium nanoparticles on the multilayer film to obtain the catalyst (PDDA / PSS) (n + 0.5 / a) AubPd for catalyzing the degradation of p-nitrophenol. According to the polyelectrolyte multilayer film loaded gold-palladium bimetallic nanoparticle catalyst disclosed by the invention, by selecting and designing the material and the layer number of the multilayer film carrier and the proportion of gold and palladium bimetallic, the synergistic catalysis of the polyelectrolyte film and the gold-palladium bimetallic nanoparticles is exerted; the catalytic efficiency and the degradation effect of the catalyst in the p-nitrophenol degradation process are obviously improved.

The invention discloses a preparation method of palladium-loaded high-crystalline carbon nitride and its application in catalytic dehydrogenation of dipentene. The preparation method of palladium-loaded high-crystalline carbon nitride comprises the following steps: calcining a nitrogen-containing precursor and mixing it evenly with an alkali metal halide salt, calcining and grinding to obtain a solid powder, and then washing, drying and grinding the obtained solid powder to obtain a high-crystalline carbon nitride; and then loading metal palladium on the high-crystalline carbon nitride by a chemical reduction method to obtain a palladium-loaded high-crystalline carbon nitride catalyst. The obtained palladium-loaded high-crystalline carbon nitride has an ordered crystal structure, nanosheet morphology, pore structure and nitrogen-rich micro-heterocyclic structure, so that the binding force between the high-crystalline carbon nitride and palladium nanoparticles is stronger, the palladium nanoparticles are small in size, uniformly dispersed and stable, and the catalytic dehydrogenation performance of dipentene is improved. The catalyst is applied to the reaction of preparing p-cymene by catalytic dehydrogenation of dipentene to obtain a high-quality p-cymene product.

The invention discloses an immersion plating method for a nano-palladium layer on the surface of a bonded oxygen-free copper wire and a palladium-plated bonded oxygen-free copper wire. Relates to the technical field of palladium-plated copper wires. According to the dip plating method for the nano-palladium layer on the surface of the bonded oxygen-free copper wire, the bonded oxygen-free copper wire is soaked in ethyl alcohol to be cleaned and dried for standby application; the preparation method comprises the following steps: dissolving a surfactant, benzotriazole and rosin in an organic solution; adding nano palladium powder to obtain a dip plating solution; carrying out dip plating treatment on the bonded oxygen-free copper wire in the dip plating solution, drying after dip plating, and carrying out vacuum annealing; the surfactant is prepared from methyl amyl alcohol, trimethylsilyl glucoside, sodium dodecyl diphenyl ether disulfonate, a carbon nano tube and deionized water. The surface active agent is added, so that nano palladium particles can be uniformly dispersed in the plating solution, the palladium particles are prevented from being agglomerated, a more uniform and compact palladium plating layer can be obtained, the quality of the plating layer is improved, and the corrosion resistance is better.

The application belongs to the technical field of wastewater treatment, and provides an electrochemical anode-cathode combined system, wherein a diaphragm divides an electrolytic cell into an anode chamber and a cathode chamber, the anode chamber is provided with a counter electrode and filled with activated carbon, the cathode chamber is provided with a working electrode and a reference electrode, the working electrode comprises a conductive base and a modified electroactive biofilm arranged on the surface of the conductive base, and the modified electroactive biofilm comprises an electroactive biofilm and palladium nanoparticles loaded on the electroactive biofilm.In the application, H* generated on the surface of the palladium nanoparticles on the electroactive biofilm can attack the carbon-halogen bond in PFASs, meanwhile, the electroactive biofilm can reduce nitrate by using electrode electrons, and then the activated carbon particles passing through the anode can be adsorbed and further purified and filtered, so that the electrochemical anode-cathode combined system provided by the application can effectively remove perfluoro / polyfluoroalkyl compounds and nitrate in wastewater at the same time.

The invention belongs to the technical field of hydrogen sensors, and particularly relates to a palladium nanoparticle-graphene composite structure, a preparation method and application thereof and a hydrogen sensor. The preparation method comprises the following steps: plating a palladium nano-film on a substrate coated with a graphene film, and then sequentially carrying out heat treatment and activation treatment, or plating a palladium nano-film on a polymer microsphere array on the surface of a graphene composite film, and then carrying out heat treatment; or plating a palladium nano film on the polymer microsphere array on the surface of the graphene composite film, and then sequentially carrying out heat treatment and activating treatment to obtain the palladium nano particle-graphene composite structure. The palladium nanoparticle-graphene composite structure has high sensitivity, selectivity, recovery speed and repeatability on hydrogen detection under the action of dual mechanisms of optimizing a hydrogen diffusion path by an oxygen-containing group on a contact interface of the graphene film and the palladium nanoparticles and improving hydrogen diffusion efficiency by the palladium nanoparticles with high coverage rate; the detection of ppb-grade hydrogen can be realized at room temperature, the accuracy is high, and the safety is good.

The invention provides a nano array for exposing a SnO2 high-activity crystal face, a preparation method of the nano array and application of the nano array in hydrogen sensing. The preparation method of the Pd-SnO2 nanowire array comprises the following steps: (1) synthesizing a SnO2 nano array on the surface of a substrate; and (2) loading the Pd nano particles on the SnO2 nano array, so as to obtain the Pd-SnO2 nanowire array. The palladium nanoparticle-loaded SnO2 nanowire array can rapidly and sensitively detect hydrogen under a low-temperature condition, has excellent sensitivity, shows excellent selectivity and reliable stability, has a detection lower limit reaching a ppm level, and is high in response speed and good in reproducibility. When the palladium nanoparticle loaded SnO2 nanowire array is used for preparing a hydrogen sensing device, the energy consumption is reduced, and the hydrogen sensing device is safer and more environment-friendly.

The invention belongs to the technical field of preparation of supported noble metal catalysts, relates to a palladium-carbon catalyst, and discloses a high-dispersion zero-valent palladium nanoparticle carbon-based catalyst and a preparation method thereof. The Pd / C catalyst comprises a main active component, a stabilizer and a carrier, the main active component is Pd, and the stabilizer is PVA (polyvinyl alcohol); the carrier is mesoporous active carbon; wherein in the palladium nano-particle carbon-based catalyst, the loading amount of Pd is 5.5-6.5 wt.% in terms of the mass sum of Pd and a carrier being 100%. According to the preparation method, PVA is adopted as a stabilizer, palladium nanoparticles are fixed on mesoporous activated carbon in a colloid form, agglomeration of the palladium nanoparticles in the heating reduction process is effectively avoided, and the stability of metal is improved; mesoporous activated carbon with high pore volume and high mesopore ratio is selected, so that the distribution space of the main active component Pd in mesopore channels is wider, and the dispersity of the active component Pd is further improved.

The invention belongs to the technical field of nano-catalyst antibiosis, and particularly relates to a zinc-based nitrogen-doped carbon-loaded metal palladium nano-enzyme as well as a preparation method and application thereof. The ZnNC-loaded metal palladium nano-enzyme is prepared by adopting a deposition-precipitation method which is simple to operate, taking ZnNC as a carrier and taking metal palladium nano-particles as an active center. The nano-enzyme has excellent oxidase-like activity, can catalyze O2 to generate hydroxyl free radicals (. OH), singlet oxygen (< 1 > O2) and superoxide anion free radicals (O2 <->) so as to kill bacteria and achieve an antibacterial effect, and has a remarkable antibacterial effect on escherichia coli under an acidic condition.

The present invention discloses a preparation method of a hydrogen sensor based on a two-dimensional material modified by a platinum-palladium dispersion, comprising: first reducing nano-palladium particles and loading them on two-dimensional layered Ti3C2T X MXene, and then centrifuging and drying to form a Ti3C2T X MXene material modified with palladium particles. Then, reducing platinum nano-materials and loading them on the Ti3C2T X MXene material modified with palladium particles, and then centrifuging and drying to obtain a Ti3C2T X MXene hydrogen-sensitive material modified by a platinum-palladium dispersion. Finally, depositing the Ti3C2T X MXene powder modified by a platinum-palladium dispersion on interdigitated electrodes to complete the preparation of the hydrogen sensor. The present invention can be used in places such as nuclear power plants, hydrogen storage bottles, and hydrogen fuel cell vehicles to effectively detect whether hydrogen leaks.

The invention provides a palladium-based catalyst as well as a preparation method and application thereof. The palladium-based catalyst comprises a carrier and active components loaded on the carrier, the active components comprise metal Pd, metal Au and alkali metal acetate, the metal Pd contains Pd nano-particles with the average diameter being smaller than 5 nm, and the Pd nano-particles with the average diameter being smaller than 5 nm account for 1%-20% of the total weight of the metal Pd. The method for preparing the palladium-based catalyst comprises the following steps: (1) dipping a carrier loaded with metal Pd (0) and metal Au (0) in a nano-palladium dispersion liquid to obtain a catalyst precursor IV; and (2) dipping the catalyst precursor IV in a solution containing alkali metal acetate to obtain the palladium-based catalyst. The palladium-based catalyst provided by the invention has excellent catalytic activity and selectivity in a vinyl acetate preparation reaction.

This invention belongs to the field of catalyst materials technology, specifically relating to a Pd-UiO-66 particle electrode, its preparation method, and its application. The Pd-UiO-66 particle electrode uses a zirconium-based metal-organic framework UiO66 as a support. Palladium nanoparticles are obtained by reducing palladium salts with sodium borohydride. The palladium nanoparticles are then reacted with the hydroxyl groups on the polyvinyl alcohol molecules. 2+ The coordination between the components and the steric hindrance effect of the long-chain molecules of polyvinyl alcohol regulate the dispersion of palladium nanoparticles, allowing palladium nanoparticles to be loaded onto UiO66 to obtain Pd-UiO-66. The Pd-UiO-66 particle cathode in this invention avoids the aggregation of palladium nanoparticles, greatly increasing the electrode area / solution volume ratio and helping to provide more active sites for dechlorination.

The invention relates to a nitrogen-rich acylhydrazone covalent organic framework material as well as a preparation method and application thereof, 5 '-(4-(hydrazinocarbonyl)-3-methoxyphenyl)-3, 3'-dimethoxy-[1, 1 ': 3', 1 '-terphenyl]-4, 4'-dicarboxylic acid dihydrazide, 1, 3, 5-tri (2-formyl pyridine-5-yl) benzene and 4, 4 ', 4' '-(1, 3, 5-triazine-2, 4, 6-triyl) tribenzaldehyde are used as construction units, and the nitrogen-rich acylhydrazone covalent organic framework material is prepared by a one-step method. The compound is synthesized by Schiff base reaction. The nitrogen-rich acylhydrazone covalent organic framework material disclosed by the invention has good chemical stability and can be used as a carrier to load palladium nanoparticles through metal coordination to obtain a composite material, and the composite material shows excellent catalytic activity and substrate universality in catalysis of Heck reaction; the method has potential application value in the fields of biological medicine, green chemistry and the like.

This invention provides a hydrogen sensor based on nanoparticles, its preparation method, and its application, belonging to the field of hydrogen sensor technology. The nanoparticle-based hydrogen sensor provided by this invention includes a substrate and at least one pair of electrodes spaced apart on the surface of the substrate. The substrate surface between the electrodes is covered with nanoparticles, and the electrode surfaces and nanoparticle surfaces are covered with a thin film layer. The nanoparticles include one or more of palladium nanoparticles, platinum nanoparticles, and alloy nanoparticles, wherein the alloy nanoparticles contain palladium and / or platinum. The material of the thin film layer includes one or more of polymethyl methacrylate, naphthol, silica, alumina, polytetrafluoroethylene, diamond-like carbon film, silicon nitride, and silicon carbide. The nanoparticle-based hydrogen sensor provided by this invention has high sensitivity and excellent stability, enabling rapid and accurate determination of hydrogen in an air environment.

This invention relates to the field of catalyst technology, and discloses a catalyst for the preparation of chloroaromatic amines, comprising palladium-based nanomaterials co-modified with an organophosphorus ligand and a metavanadate. The palladium-based nanomaterials consist of palladium nanoparticles and a carbon support. The palladium nanoparticles include zero-valent palladium and positive-valent palladium. Phosphorus in the organophosphorus ligand forms a palladium-phosphorus coordination bond with the zero-valent palladium, and metavanadate ions in the metavanadate form a vanadium-oxygen-palladium chemical bond with the positive-valent palladium. The catalyst provided by this invention exhibits high conversion and high selectivity in the catalytic hydrogenation of chloronitroaromatic hydrocarbons to prepare chloroaromatic amines, with virtually no formation of byproducts such as chlorohydroxyaromatic amines, azo compounds, and dechlorination products, and the reaction conditions are mild.

The present invention discloses an anode catalyst, system and method for preparing glycolic acid from ethylene glycol by electrocatalysis, wherein the anode catalyst comprises a foam metal and a metal hydroxide nanosheet grown in situ on the foam metal; the metal hydroxide nanosheet is loaded with metal palladium nanoparticles. The anode catalyst provided by the present invention can exhibit excellent performance in preparing glycolic acid from ethylene glycol by electrocatalysis, specifically, when the industrial grade current density (600mA / cm 2 ), the operating voltage is only 1.15V; when the ethylene glycol conversion is 93.2%, the selectivity of glycolic acid is as high as 91.6%; in addition, the catalyst can achieve stable electrolysis for more than 200 hours, which is better than all current palladium-based catalysts.

The invention relates to a nano MoS2 and PtPd combined BN / Au film sensor as well as a preparation method and application thereof, and belongs to the technical field of biosensors. According to the sensor, a glassy carbon electrode serves as a substrate, a boron nitride nanosheet, a gold film and a primary antibody are sequentially modified, a molybdenum disulfide composite material loaded with platinum-palladium nanoparticles and a secondary antibody are coupled to serve as a signal amplification probe, and thionine serves as an electron mediator. The preparation method comprises the steps of electrode pretreatment, BN / Au film modification, antibody fixation, nano composite probe preparation and the like. The sensor solves the problems that an existing detection method is complex in operation, depends on large-scale equipment and is difficult to meet POCT requirements, has the advantages of being high in sensitivity (the detection limit reaches 0.86 pg / mL), high in specificity, good in stability and suitable for rapid detection of serum samples, and provides an effective tool for early diagnosis of tumors.

A method for producing a nano-Pd catalyst supported on a nitrogen-doped hierarchical porous carbon, characterized in that it comprises: 1) Preparation of a nitrogen-doped hierarchical porous carbon, 2) Mixing the nitrogen-doped hierarchical porous carbon produced in step 1) with water and adjusting the pH of the mixed solution to alkaline. 3) Mixing the mixture solution prepared in step 2) with the aqueous solution of Pd metal precursors, adding reducing agent and obtaining the nano-Pd catalyst supported on the nitrogen-doped hierarchical porous carbon after reduction.

The invention provides a preparation method of a tetrahydrofuran hydrogenation catalyst, and belongs to the field of tetrahydrofuran catalysts. The method comprises two main steps of in-situ synthesis of a functionalized metal organic framework carrier and microwave-assisted palladium nanoparticle loading. The functional MOF carrier with abundant active sites is synthesized by introducing a specific organic ligand and an auxiliary agent; and uniformly loading palladium nanoparticles on the surface of the carrier by adopting a microwave-assisted technology to form the efficient hydrogenation catalyst. The catalyst shows excellent catalytic activity, selectivity and stability in a tetrahydrofuran hydrogenation reaction, and has a good industrial application prospect.