17 results about "Defective graphene" patented technology

The invention discloses a hydrogen energy fuel cell catalyst carrier based on a graphene graft polymer, which is characterized in that two-dimensional graphene is used as a substrate, the surface of the two-dimensional graphene is modified with an oxygen-containing functional group, and a functional polymer branch chain containing nitrogen, sulfur or phosphorus heteroatoms is covalently grafted to form a local three-dimensional network winding structure; the carrier is loaded with platinum, palladium, ruthenium and other metal or alloy nanoparticles, the particle size is 2-8 nm, the loading capacity is 10%-40%, and the particles are anchored to polymer functional sites or reduced in situ to a graphene defect area through coordination. A polymer branch chain has pH responsiveness and can adjust the local proton transmission efficiency; the grafting density is 3-15 grafting points per 100 carbon atoms, so that high dispersion and stable anchoring of metal particles are effectively realized; the specific surface area of the carrier is 400-800m < 2 > / g, the electrochemical active area is not less than 80m < 2 > / g, and the activity retention rate is greater than 80% after 5000 circles of accelerated durability tests. The activity, the stability and the proton conduction performance of the catalyst are remarkably improved, and the catalyst is suitable for high-performance fuel cells.

The invention relates to the technical field of new energy materials, in particular to a method for simulating hydrogen evolution performance of Co and Fe double-metal atoms on the surface of defect-state graphene, and aims to simulate the electronic structure performance and reaction mechanism of Co and Fe double-atom hydrogen evolution under modification of Co, Fe and N on the surface of the defect-state graphene by optimizing a modified material structure. A density functional theory of a first principle and a molecular dynamics analogue simulation method are adopted, and the relationship between the structure and hydrogen evolution performance of defect-state graphene metal diatoms and N-modified metal diatom modified materials is studied; the interaction rule between pi electrons in the carbon material under the defect and outer layer electrons of Co and Fe double atoms and Fe, Co and N three atoms is disclosed; therefore, a Co and Fe diatom and Co, Fe and N triatom-graphene two-dimensional material high-efficiency hydrogen evolution mechanism is disclosed, and a theoretical foundation is laid for developing a novel high-efficiency hydrogen evolution material.

This invention relates to the field of functional materials technology, and particularly to a floating defective g-C3N4 / PDI composite thin-film photocatalyst, its preparation method, and its application. The preparation method of the floating defective g-C3N4 / PDI composite thin-film photocatalyst provided by this invention includes the following steps: mixing defective graphene carbon nitride, N,N'-bis(3-aminopropyl)perylene-3,4,9,10-tetracarboxylic acid diimide (PDI), an organic base, and water to obtain a first suspension; mixing the first suspension with a monohaloacetic acid to undergo a protonation reaction, followed by solid-liquid separation to obtain a protonated composite material; mixing the protonated composite material with a thermoplastic resin solution to obtain a second suspension; and forming the second suspension into a film and then drying it to obtain the floating defective g-C3N4 / PDI composite thin-film photocatalyst. This photocatalyst is recyclable after use, does not cause secondary pollution to the environment, and exhibits excellent photocatalytic performance.

The invention discloses a preparation method of high-strength and high-toughness graphene-doped composite copper foil, which comprises the following steps: S1, treating graphene by adopting a high-energy ball milling method to obtain nano-sized defective graphene; s2, preparing a composite electrolyte containing the defective graphene, and adding the composite electrolyte into an industrial electrolytic cell after ultrasonic dispersion; s3, adding a compound additive into the electrolytic bath, and uniformly mixing through air blowing and ultrasound; s4, direct current is introduced, so that graphene and copper ions are co-deposited on the surface of the cathode roller to prepare a composite copper foil; and S5, carrying out acid pickling, water washing, drying, stripping and rolling on the composite copper foil. According to the invention, through doping of nano-scale defective graphene, on one hand, active sites are provided for copper deposition so as to refine grains, increase grain boundaries and hinder dislocation motion; on the other hand, due to the fact that the size of the defective graphene is matched with the height of copper grains, the strength can be improved through dislocation pinning and back stress strengthening, meanwhile, a multi-slip system is activated, dislocation storage is promoted to improve plasticity, the balance dilemma of the strength and the ductility of the copper foil is broken through finally, the copper foil has the high-strength and high-toughness characteristics, and the design requirement for the high energy density of the lithium ion battery is met.

The invention relates to the technical field of functional materials, in particular to a floating type defect g-C3N4 / PDI composite film photocatalyst as well as a preparation method and application thereof. The preparation method of the floating type defect g-C3N4 / PDI composite film photocatalyst provided by the invention comprises the following steps: mixing defect type graphene carbon nitride, N, N '-bis (3-aminopropyl) perylene-3, 4, 9, 10-tetracarboxylic diimide (PDI), organic alkali and water to obtain a first suspension; mixing the first suspension with halogenated acetic acid, carrying out protonation reaction, and then carrying out solid-liquid separation to obtain a protonated composite material; and mixing the protonated composite material with a thermoplastic resin solution to obtain a second suspension, forming a film from the second suspension, and drying to obtain the floating type defect g-C3N4 / PDI composite film photocatalyst. The photocatalyst can be recycled after being used, does not cause secondary pollution to the environment, and has excellent photocatalytic performance.

This invention discloses a defective graphene-reinforced battery composite electrode and its preparation method, comprising a current collector, a defective graphene conductive coating, and an electrode active material layer; the defective graphene conductive coating is disposed on both sides of the current collector; the electrode active material layer is coated on the defective graphene conductive coating on both sides or on one side; and / or the electrode active material layer is doped with defective graphene nanosheets, or the composite electrode is in the form of a self-supporting electrode, composed of multilayer stacked defective graphene conductive films, the films containing nanopores and defect sites. This invention fully utilizes the high chemical activity of graphene defect sites, enabling it to have the triple functions of conductive additive, bonding bridge, and active lithium storage medium, synergistically optimizing the electrode microstructure and interface performance.

This invention discloses an electrochemical sensor, its preparation method, and its application. By using DMF to modify the surface of a SnO2 / Gr / GCE electrode, the carbonyl (C=O) and amino (-N(CH3)2) groups in the DMF molecules interact weakly (hydrogen bonding and van der Waals forces) with hydroxyl (-OH) groups on the SnO2 surface or graphene defect sites, effectively reducing the electrode interface resistance and enhancing conductivity. The electrode exhibits an electron transfer kinetic resistance as low as 4.78Ω, making it suitable for the detection of 6-BA in plants or the environment.

The application discloses a controllable preparation method of a graphene film containing topological structure defects, and comprises the following steps: selecting a carbon source precursor molecule containing one or more non-six-membered ring topological structure units in a molecular skeleton; placing a metal substrate in a reaction furnace and heating to a growth temperature; introducing the vaporized carbon source precursor molecule into the reaction furnace from a carrier gas, pyrolyzing, nucleating and growing a graphene film on the surface of the metal substrate, and in-situ retaining the non-six-membered ring topological structure units in a graphene lattice to form topological defects; controlling the density and distribution of the topological defects; and obtaining the defective graphene film after cooling. The application realizes the engineering controllable regulation of the defect density of graphene on a macroscopic scale, is the first in the field of molecular template guided graphene defect engineering, and can be used for preparing graphene functional materials with on-demand designed performance, and has a wide application prospect in the fields of sensing, catalysis, energy storage and electronic devices.

The invention relates to a high-compaction lithium iron phosphate positive electrode material, a preparation method thereof and a lithium ion battery, and belongs to the technical field of batteries, the method adopts a two-step synthesis method, the first step adopts ferrous phosphate high-grinding sintering to prepare first-sintering large particles, and adopts in-situ doped iron phosphate low-grinding to prepare first-sintering small particles; 2, performing high grinding on the first-fired large particles, performing low grinding on the first-fired small particles, accurately controlling the sizes of the small particles, and stripping C3N4 through grinding to form g-C3N4; the large and small particles are mixed according to a certain mass ratio, and then secondary sintering is carried out to prepare the high-compaction high-capacity long-circulation lithium iron phosphate material, the advantages of different precursors are utilized, the particle composition is optimized, and the roundness of the large and small particles is better; meanwhile, the nitrogen-doped carbon layer is prepared by taking defect-type graphene and high-molecular organic nitride which are converted from C3N4 in a secondary sintering process as carbon sources, so that the conductivity and the cycle performance of the material are improved.

This invention discloses a method for on / off modulation of the hydrogen evolution reaction (HER) by defect-induced ferroelectric-antiferroelectric transition in graphene and its application. The method constructs a bilayer system of defective graphene (D-graphene) containing g-C₃N₄-like vacancy pores and g-C₃N₄ layers, with the layers coupled by van der Waals forces. A reversible ferroelectric-antiferroelectric phase transition is achieved through interlayer slip, and the HER is precisely modulated using changes in polarization intensity and direction. The defective graphene bilayer can form an ON-OFF ferroelectric switch, with the Gibbs free energy ΔG for ferroelectric hydrogen adsorption. H * Approaching the optimal value, the catalysis is in the on state; however, excessive hydrogen adsorption in the antiferroelectric state leads to catalysis shutdown. The g-C₃N₄ bilayer can achieve three-level regulation (ON-OFF-ON) through ferroelectric-paraelectric-ferroelectric polarization switching, with the ferroelectric polarization state significantly enhancing HER activity. This invention is free of precious metals, has a low interlayer sliding barrier, and exhibits catalytic performance comparable to platinum-based catalysts. It provides a new strategy for the design of highly efficient intelligent electrocatalysts and novel catalytic switching devices, and has significant application value in the field of clean energy.

This invention relates to the field of catalysts for the hydrogenation of nitrobenzene to aniline, specifically disclosing a magnetically separable carbon-supported platinum cluster catalyst, its preparation method, and its applications. The magnetically separable carbon-supported platinum cluster catalyst comprises platinum nanoparticles as the active component and a nickel-coated nitrogen-doped graphene composite material as the support. The nickel-coated nitrogen-doped graphene composite material has a core-shell structure, with platinum nanoparticles uniformly loaded in clusters on the surface of the nitrogen-doped graphene, bonding with carbon and nitrogen atoms on graphene defects. The high utilization rate of platinum atoms enables efficient hydrogenation of nitrobenzene even at low loading levels, while also making the catalyst structure more stable. The support surface has abundant carbon defects and oxygen-containing functional groups, which facilitates the anchoring of platinum nanoparticles to the support surface through strong interactions between the metal and the support. The magnetic nickel nanoparticles impart a certain degree of magnetism to the catalyst, allowing for dispersion and recovery of the catalyst simply by removing and applying a magnetic field.

This invention provides a preparation method and application of a novel memristor for neural network visual perception. Using ultrasonic atomization deposition, molybdenum disulfide nanosheets are asymmetrically deposited on a defective graphene electrode through a mask on a silicon dioxide substrate. Heating then induces partial oxidation of the graphene and molybdenum disulfide, forming an asymmetric photovoltaic-effect graphene oxide / oxygen-doped molybdenum sulfide / graphene oxide device, which serves as a novel memristor for neural network visual perception. This invention proposes a novel device, preparation method, and application that modulates the photoresponsivity of devices at both ends by memorizing the electrical flux flowing through the device.

The invention relates to a high-conductivity graphene / copper thin film material based on a plasma processing technology and a preparation method thereof. The high-conductivity graphene / copper thin film material comprises an insulating substrate, a copper thin film and a graphene thin film which are sequentially stacked, the graphene film has graphene defects prepared through a plasma processing technology. Graphene defects are regulated and controlled by adjusting plasma etching time and radio frequency power supply power, interface bonding of graphene and a copper matrix can be further enhanced, and therefore the conductivity of the composite material is improved.

The invention relates to the technical field of semiconductor optoelectronic device preparation, in particular to a multi-dimensional mixed Micro / Nano LED array and a preparation method thereof. The substrate comprises a substrate from bottom to top; a defective graphene film; the two-dimensional transition metal compound graphic array is positioned at a defect site of the defective graphene film; the co-metal electrode is located in the area, not covered by the two-dimensional transition metal compound pattern array, of the defective graphene film; the nitride Micro / Nano-LED array is only stacked on the two-dimensional transition metal compound pattern array; the metal top electrode is positioned on the upper surface of the nitride Micro / Nano-LED array; the photosensitive composite filling layer is located in a gap which is not covered by the nitride Micro / Nano-LED array, and the photosensitive composite filling layer and the top end of the array are kept at the same height. The method has the advantages that the device array size is controllable; the metal nanoparticles provide a scattering path for lateral propagation light; the luminous efficiency is improved.

The invention provides a method for rapidly repairing laser-induced graphene defects, a strain sensor and a preparation method of the strain sensor. The method for rapidly repairing the laser-induced graphene defect comprises the following steps: performing flash Joule heating on a laser-induced graphene material to obtain flash Joule heated laser-induced graphene, and completing the repair of the laser-induced graphene defect. The strain sensor comprises a flexible substrate layer, a flash Joule heating laser-induced graphene layer arranged on the flexible substrate layer, and electrode connection areas arranged at the two ends of the flash Joule heating laser-induced graphene layer. The preparation method of the strain sensor comprises the following steps: preparing a laser-induced graphene material on a polyimide substrate; and performing flash Joule heating on the laser-induced graphene material to obtain the strain sensor. According to the method, the inherent topological defect in the LIG can be rapidly repaired, and meanwhile, the macroscopic pattern integrity and the microcosmic porous structure of the LIG can be kept.

The application discloses a kind of low-defect few-layer graphene water-based conductive paste and its preparation method and application, belong to conductive paste technical field;Low-defect few-layer graphene water-based conductive paste of the application, by weight fraction, including 1~3 mass fraction low-defect few-layer graphene, 100 mass fraction ultrapure water, 0.8~1.2 mass fraction conductive additive;The low-defect few-layer graphene is first to graphite powder at room temperature intercalation, then chemical expansion is carried out, and then water phase stripping is obtained using 5 '-adenine nucleotide salt aqueous solution;The conductive additive is amphiphilic polythiophene;The amphiphilic polythiophene is treated to obtain using hydrogen bromide and anhydrous acetic anhydride after polymerization with 2,5-dibromo-3-triethylene glycol monomethyl ether thiophene, 3-[10-(4-methylphenyl ether) decyl)] thiophene as monomer;The low-defect few-layer graphene water-based conductive paste prepared by the application has less graphene defects, good dispersibility and good conductivity.

The invention discloses a graphene / copper composite film layer-by-layer stacked high-conductivity copper film and a preparation method and application thereof.The preparation method comprises the following steps that S1, an insulating substrate is provided, a high-purity copper source serves as a material, and a copper film with the thickness ranging from 50 nm to 800 nm is deposited on the surface of the substrate through a physical vapor deposition technology; s2, growing a layer of graphene film with the coverage rate of 60%-90% on the surface of the copper film by adopting a chemical vapor deposition process to prepare a graphene / copper composite film; and S3, repeating the process of the steps S1 to S2 to obtain the product. According to the method, the conductivity of the metal copper film is improved by alternately and repeatedly depositing the copper and the defective graphene, so that the conductivity of the prepared copper film is greatly improved and even reaches 115.33% IACS (International Annealed Copper Standard), the fusing current is relatively high, the conductivity of the copper film is remarkably improved by the method, and the method is suitable for industrial production. The problem of low conductivity of copper materials in the field of integrated circuits can be effectively solved.