1920 results about "Doped graphene" patented technology

The invention discloses a doped graphene and a preparation method thereof. The doped graphene is prepared by adopting a chemical vapor deposition method, which comprises the steps as follows: a substrate with catalyst is put into a reaction kettle without oxygen, with the temperature of the substrate being 500 DEG C to 1200 DEG C; then material with carbon element and doped elements is piped into the reaction kettle, and the doped graphene is obtained; the catalyst is metal or metallic compound. The doped graphene prepared by the invention has good quality, and the preparation method is simple and feasible and can be conveniently operated and used for large-scale production.

The invention relates to a method for preparing nitrogen-doped graphene, in particular to a novel simple, convenient and scale method for preparing nitrogen-doped graphene at high temperature under the protection of inert gas by taking melamine as a nitrogen source. In the method, graphene oxide and the melamine are taken as raw materials, wherein the melamine is taken as the nitrogen source and the graphene oxide is taken as a carbon source; high temperature annealing is carried out in the atmosphere of inert gas, and the reduction of the graphene oxide and the nitrogen doping of graphene are realized; and by controlling reaction conditions such as temperature, time, the ratio of the raw materials and the like, graphene products with different nitrogen doping ratios can be prepared. The preparation method is simple and practicable; catalysts are not needed; the reaction process is easy to control; special requirements on equipment do not exist; the cost is low; and the method is easy to promote and use.

The invention provides preparation and application of a nitrogen doped graphene fuel cell catalyst, wherein a preparation method of the nitrogen doped graphene fuel cell catalyst is characterized by comprising the following steps: dispersing graphene oxide into a solvent, and carrying out ultrasonic treatment, thereby obtaining a graphene solution; dispersing at least one of non-noble metal salt as well as hydrate thereof and nitrogenous small organic molecules into the solvent, thereby obtaining a mixed solution; dropping the graphene oxide solution into the mixed solution, drying the solvent by distillation, thereby obtaining a nitrogen doped graphene precursor, warming to 600-1000 DEG C under the protection by inert gases, keeping the temperature for 1-4 hours, and cooling naturally, thereby obtaining the doped graphene catalyst. The nitrogen doped graphene preparation process provided by the invention is simple; required raw materials are low in cost, high in yield, can achieve industrial production easily, have very high oxygen reduction catalytic activity, can be applied to the fields of fuel cells, metal-air cells as well as microorganism fuel cells and the like.

The invention relates to a method for preparing sulfur-doped graphene films. The sulfur-doped graphene films are prepared with chemical vapor deposition. The method comprises the following steps: a metal substrate is put in a reactor and preheated in heating and reduction protective atmosphere, then the metal substrate is heated to 900-1000 DEG C, the reduction protective gas is stopped to blow in the reactor, the vacuum degree of the reactor reaches 10-2 Torr to 10-3 Torr, then mixed liquid carbon source and sulfur source are introduced into the reactor in gas state, the required sulfur-doped grapheme films are grown on the metal substrate, a post-treatment is carried out, and the sulfur-doped graphene films are transferred to a substrate material.

A transparent electrode on at least one surface of a transparent substrate may include graphene doped with a p-dopant. The transparent electrode may be efficiently applied to a variety of display devices or solar cells.

A composition including graphene; and a dopant selected from the group consisting of an organic dopant, an inorganic dopant, and a combination including at least one of the foregoing.

The invention relates to the field of graphene electrode materials, and in particular relates to a doped graphene electrode material, a macro preparation method as well as an application of the doped graphene electrode material in a high-capacity high-multiplying-power lithium ion battery. In the invention, graphene is taken as a raw material. The preparation method comprises the following steps: controlling the temperature rising speed rate through shielding gas; introducing gas containing nitrogen or boron elements in different concentrations at high temperature so as to realize the doping of heteroatoms of the graphene, and get the nitrogen or boron doped graphene; mixing the doped graphene, conductive carbon black and a bonding agent; adding a solvent; coating the mixture on a current collector after grinding; taking the mixture after drying, shearing and tabletting as a working electrode; adding electrolyte containing a lithium salt by taking a lithium plate as a counter electrode / reference electrode; assembling into a button-type lithium ion half-battery in a glove box; and carrying out constant current charge and discharge tests under the condition of high current density. According to the invention, the electrode stability of the material under the condition of high current density is improved, and the fact that the doped graphene has higher specific capacity and excellent cycle performance in a shorter time is realized.

The invention relates to a method for forming graphene quantum dots, and in particular, to doped graphene quantum dots. The graphene quantum dots are co-doped with nitrogen and sulfur. The co-doped elements introduce a new type and high density of surface state of graphene quantum dots, leading to high yield and excitation-independent emission.

A ceramic capacitor comprising at least a dielectric ceramic layer and at least a graphene electrode layer deposited on the ceramic layer, wherein the graphene electrode layer has a thickness no less than 2 nm and consists of a graphene material or a graphene composite material containing at least 0.1% by weight of a graphene material dispersed in a matrix material or bonded by a binder material, wherein the graphene material is selected from (a) a plurality of single-layer or multi-layer pristine graphene sheets having less than 0.01% by weight of non-carbon elements, or (b) one or a plurality of a non-pristine graphene material having at least 0.01% by weight of non-carbon elements, wherein the non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof.

Provided is an integral 3D graphene-carbon hybrid foam composed of multiple pores and pore walls, wherein the pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1 / 100 to 1 / 2, wherein the few-layer graphene sheets have 2-10 layers of stacked graphene planes having an inter-plane spacing d002 from 0.3354 nm to 0.40 nm and the graphene sheets contain a pristine graphene material having essentially zero % of non-carbon elements, or a non-pristine graphene material having 0.01% to 25% by weight of non-carbon elements wherein said non-pristine graphene is selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof. Also provided are a process for producing the hybrid form, products containing the hybrid foam, and its applications.

Disclosed is a facile and cost effective method of producing nano silicon powder or graphene-doped silicon nano powder having a particle size smaller than 100 nm. The method comprises: (a) preparing a silicon precursor / graphene nano composite; (b) mixing the silicon precursor / graphene nano composite with a desired quantity of magnesium; (c) converting the silicon precursor to form a mixture of graphene-doped silicon and a reaction by-product through a thermal and / or chemical reduction reaction; and (d) removing the reaction by-product from the mixture to obtain graphene-doped silicon nano powder.

The invention provides a nitrogen-doped graphene catalyst and a preparation method and application thereof. The nitrogen-doped graphene catalyst is characterized by being prepared by roasting a nitrogen-doped graphene precursor; the nitrogen-doped graphene precursor is prepared from the raw materials including at least one of non-precious metal salt and hydrate thereof, graphite oxide and nitrogen-containing small organic molecules; in the raw materials, the mass percent of the graphite oxide is 10-89wt%, the mass percent of the nitrogen-containing small organic molecules is 10-89wt%, and the mass percent of at least one of non-precious metal salt and hydrate thereof is 1-10wt%. The preparation process of the nitrogen-doped graphene provided by the invention is simple, the process is easy to operate, the activity is high, the cost is low, and industrial production is easy to implement; the nitrogen-doped graphene can be applied to the fields of fuel cells, metal-air cells, microbial fuel cells and the like.

The present disclosure relates to roll-to-roll doping method of graphene film, and doped graphene film.

An infrared photoconversion device comprising a collector with at least an active layer made of a single sheet of doped single-layer, bilayer, or multilayer graphene patterned as nanodisks or nanoribbons. The single sheet of doped graphene presents high absorbance and thus, the efficiency of devices such as photovoltaic cells, photodetectors, and light emission devices can be improved by using graphene as the central absorbing or emitting element. These devices become tunable because their peak absorption or emission wavelength is changed via electrostatic doping of the graphene.

The invention provides a preparation method of nitrogen doped graphene and an application of the nitrogen doped graphene in super capacitors. The preparation method of the nitrogen doped graphene specifically comprises the following steps: putting a carbon material and a compound containing active nitrogen elements in an enclosed container, and heating to a temperature of 100 to 300 DEG C so as to obtain the nitrogen doped graphene. In the preparation process of the nitrogen doped graphene, under a heating condition, nitrogen elements in the compound containing active nitrogen elements are mixed into the carbon material so as to obtain the nitrogen doped graphene. The nitrogen doped graphene preparation method mentioned above avoids adopting a high reaction temperature, and has the advantages of mild preparation conditions and low production cost. The prepared nitrogen doped graphene is used as an electrode material of a super capacitor, and the specific capacity of the super capacitor can reach 190 F / g, when the electric current density is 5 A / g. The capacity retention ratio is 96.3% after 10000 times of circulation.

The invention discloses a double-functional catalyst of carbon-based non-noble-metal oxygen electrode and a preparation method thereof. The catalyst is a composite material composed of metal, metal oxide grains, N-doped graphene, carbon spheres and nanotubes. The preparation method of the catalyst comprises the following steps of: 1) weighing graphite oxide or graphene oxide, the carbon spheres, a metal compound and a nitrogen-containing heterocyclic compound according to ratios; carrying out ultrasonic treatment on the raw materials in a solvent; uniformly agitating and sufficiently drying to obtain a precursor; and 2) carrying out high-temperature pyrolysis in a precursor inert atmosphere to obtain a composite material catalyst. The catalyst provided by the invention not only has the advantages of high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic performances, good stability and excellent CH3OH / CO tolerance, but also the cost of the raw materials is low, and the preparation method is simple and is easy to operate.

The invention provides a preparation method of three-dimensional porous heteroatom-doped graphene. The preparation method comprises the following steps: (1) uniformly dispersing graphene oxide, a heteroatom precursor, a non-noble metal salt and a template agent into a solvent, thereby obtaining a precursor after heating, stirring and drying; (2) performing high-temperature roasting treatment on the precursor in the presence of inert gases, thereby obtaining solid products; and (3) treating the solid products by a blended solution of hydrofluoric acid and hydrochloric acid, removing the template and metals by one step, and then, re-heating to obtain the three-dimensional porous heteroatom-doped graphene. The invention further provides a method adopting the three-dimensional porous heteroatom-doped graphene to prepare a membrane electrode combined body. The three-dimensional porous heteroatom-doped graphene disclosed by the invention has a high specific surface area, and has a good application prospect in the fields such as fuel batteries, metal-air batteries as well as supercapacitors.

The invention relates to a novel composite material, and particularly relates to a preparation method and application of a nitrogen-doped graphene and cobaltosic oxide hollow nanosphere composite material. The novel composite material comprises a doped graphene substrate and cobaltosic oxide hollow nanospheres which is attached to the surface of the doped graphene substrate. Melamine resin is taken as a cross-linking reagent for integrating graphite oxide with Co<2+> into a single coordination precursor. The preparation method comprises the following steps: in a pyrolysis process of the precursor, taking the melamine resin as a new nitrogen source to uniformly dope the graphene with nitrogen, fixing cobalt oxide which is generated in situ, and finally preparing the nitrogen-doped graphene / Co3O4 hollow nanosphere composite material with a sandwich structure. The composite material has a graded porous structure, is high in specific surface area, more in active sties, good in electron conductivity and ion conductivity, and good in application prospect in the field of new energy resources and catalysis.

The invention discloses a method for preparing boron doped grapheme, which is characterized in that reactive metal is used for reacting with low carbon halogenated hydrocarbon and boron source, in-situ boron doped grapheme can be realized under specific reaction condition. Compared with grapheme prepared by chemical vapor deposition and arc discharge method, the method of the invention has the advantages of simple operation, safety, no toxicity, low cost, less defect, good conductivity, high quality boron doped grapheme. The obtained grapheme possesses wide application prospect in the fields of solar energy batteries of photoelectric devices such as copper indium gallium selenium, cadmium telluride and dye sensitization, flat display, super capacitor, field emission material and lithium ion battery.

The invention discloses a three-dimensional nitrogen-doped graphene composite material as well as a preparation method and an application thereof to electrochemical biosensors. By means of the characteristics such as high specific surface area, good biocompatibility and high conductivity of the three-dimensional nitrogen-doped graphene, the three-dimensional nitrogen-doped graphene composite material is constructed; the preparation method comprises the following steps: obtaining substrate-containing three-dimensional nitrogen-doped graphene by taking a foam material as a substrate and utilizing a chemical vapor deposition (CVD) method in the presence of inert gas, hydrogen, a carbon source and a nitrogen source, and obtaining the three-dimensional nitrogen-doped graphene composite material by etching and cleaning the three-dimensional nitrogen-doped graphene. By compounding the three-dimensional nitrogen-doped graphene with enzyme / non-enzyme materials, corresponding three-dimensional nitrogen-doped graphene composite materials can be obtained; the three-dimensional nitrogen-doped graphene composite materials are prepared into electrodes and have the characteristics of being high in current corresponding sensitivity, good in stability and wide in application range when being used for detecting a plurality of molecules such as glucose, dopamine, paracetamol and the like.

The invention relates to a chemical preparation method for a nitrogen-doped graphene quantum dot, belonging to the technical field of nano materials. The invention particularly relates to a preparation method for the nitrogen-doped graphene quantum dot. The method comprises the following steps: firstly, by taking graphite oxide as a carbon source and glycine as a nitrogen source, preparing a nitrogen-doped graphene sheet under a high-temperature annealing condition; then, cutting the deeply oxidized nitrogen-doped graphene sheet into an oxidized nitrogen-doped graphene nano sheet; preparing the nitrogen-doped-graphene quantum dot with super-strong blue fluorescence by way of a hydrothermal reaction. The synthetic method of the nitrogen-doped graphene quantum dot provided by the invention is simple in synthetic process, all raw materials are cheap and easy to get in the market, and the prepared nitrogen-doped graphene quantum dot is high in purity and yield, mono-dispersible and good in water solubility, has a very strong blue fluorescence performance and has a very good application prospect in the application fields of lithium batteries, micro supercapacitors, biological fluorescent labels, solar batteries and the like.

The invention relates to a method for preparing a low-temperature nitrogen-doped graphene supported nano Pd hydrogenation catalyst. The method comprises the following steps: ultrasonically stripping graphite oxide, thereby obtaining an aqueous solution of highly dispersed graphite oxide; selecting different nitrogen sources, and synthesizing nitrogen-doped graphene at low temperature through a hydrothermal method; and performing ultrasonic treatment on the nitrogen-doped graphene, adding a certain amount of PdCl2 solution, and adding a reducing agent, thereby preparing the highly dispersed supported nano Pd hydrogenation catalyst by a chemical reduction method. Because nitrogen atoms, which contain lots of lone pair electrons and can achieve a coordination effect with metal nanoparticles, are mixed into a carbon skeleton of graphene, runoff and conglomeration of the metal nanoparticles are effectively avoided, and the dispersity of the metal nanoparticles on the surface of graphene is improved. The catalyst is used for a hydrogenation reaction of olefins and has extremely high catalytic activity and high reusability. The catalyst is simple in preparation method and low in cost, the nitrogen content is high, doped nitrogen is controllable, and industrial production is easily realized.

Provided is a lithium or sodium metal battery having an anode, a cathode, and a porous separator and / or an electrolyte, wherein the anode contains an integral 3D graphene-carbon hybrid foam composed of multiple pores, pore walls, and a lithium-attracting metal residing in the pores; wherein the metal is selected from Au, Ag, Mg, Zn, Ti, Na, K, Al, Fe, Mn, Co, Ni, Sn, V, Cr, or an alloy thereof and is in an amount of 0.1% to 50% of the total hybrid foam weight or volume, and the pore walls contain single-layer or few-layer graphene sheets chemically bonded by a carbon material having a carbon material-to-graphene weight ratio from 1 / 200 to 1 / 2, wherein graphene sheets contain a pristine graphene or non-pristine graphene selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof.

Provided is a lithium or sodium metal battery having an anode, a cathode, and a porous separator and / or an electrolyte, wherein the anode contains a graphene-metal hybrid foam composed of multiple pores, pore walls, and a lithium- or sodium-attracting metal residing in the pores; wherein the metal is selected from Au, Ag, Mg, Zn, Ti, Na (or Li), K, Al, Fe, Mn, Co, Ni, Sn, V, Cr, or an alloy thereof and is in an amount of 0.1% to 90% of the total hybrid foam weight or volume, and the pore walls contain single-layer or few-layer graphene sheets, wherein graphene sheets contain a pristine graphene or non-pristine graphene selected from graphene oxide, reduced graphene oxide, graphene fluoride, graphene chloride, graphene bromide, graphene iodide, hydrogenated graphene, nitrogenated graphene, doped graphene, chemically functionalized graphene, or a combination thereof.

The invention provides a transition metal nitride / nitrogen-doped graphene nanometer composite material and a preparation method and application thereof. In the composite material, transition metal nitride nanoparticles with sizes being 5-20 nanometers are embedded into a nitrogen-doped graphene framework, and the composite material is relatively large in specific area, contains mesopores uniformlydistributed and has favorable electrical conductivity. The preparation method of the composite material comprises the steps of (1) mixing a template precursor, a carbon source and a metal source to obtain a mixed material; and (2) placing the mixed material of the step (1) in an atmosphere furnace, and performing calcination in a non-oxidization atmosphere to obtain the transition metal nitride / nitrogen-doped graphene nanometer composite material. The composite material is used for the supercapacitor, a fuel cell or a lithium ion battery and has excellent application prospect. Compared with the prior art, the preparation method of the composite material is simple in process, low in equipment requirement and low in energy consumption, the raw material is low in cost, and mass production iseasy.

The invention provides a preparation method of high-nitrogen-doped graphene nanoparticles and application of the high-nitrogen-doped graphene nanoparticles as a negative material of a lithium ion battery. The corresponding method comprises the following steps: slowly dropwise adding a preset quantity of zinc nitrate (Zn(NO3)) methanol solution into a methanol mixed solution which is prepared from a preset amount of 2-methylimidazole (C4H6N2) and a preset amount of polyvinylpyrrolidone (PVP), magnetically stirring and standing for preset time, carrying out centrifugal separation to obtain ZIF-8(a complex formed by zinc and 2-methylimidazole) nanoparticles; and putting the obtained ZIF-8 nanoparticles in a high-temperature furnace and calcining at 600-1,000 DEG C for preset time in the nitrogen atmosphere to obtain the high-nitrogen-doped graphene nanoparticles. The preparation process of the high-nitrogen-doped graphene nanoparticles is simple, and the high-nitrogen-doped graphene nanoparticles are uniform in shape, relatively large in specific surface and high in content of nitrogen, and have great application potentials in aspects of lithium ion batteries, electrochemical energy storage, catalysis and the like. The preparation method of the high-nitrogen-doped graphene nanoparticles is simple and efficient, safe and liable to implement, short in synthesis cycle, is capable of preparing a large quantity of high-nitrogen-doped graphene nanoparticles and is expected to be popularized and industrially applied.

The invention discloses a graphene fiber and a preparation method thereof, wherein the graphene fiber is a composite fiber obtained by doping graphene fiber with metal nanowires, the composite fiber comprises the main components of graphene and the metal nanowires, wherein the mass ratio of the metal nanowires is 0.1% ~ 50%, the graphene is in lamellar morphology, and the metal nanowires and the graphene layers are parallelly and simultaneously arranged along the axial direction of the graphene fiber. The metal nanowire doped graphene fiber is a new high performance and multifunctional fiber material, by doping of the metal nanowires, fiber conductive rate is greatly improved, meanwhile the graphene fiber exhibits good tensile strength and excellent toughness, has the very strong potential application value in many fields such as use as lightweight flexible wires and the like.

The invention relates to a method for preparing a doped graphene or graphene-like compound, and belongs to the fields of preparation of nanomaterial and preparation of fuel cell nano electrocatalyst. The method comprises the steps: with a nano-oxide or carbon as a carrier, or without use of a carrier, a mixture of one or more than two of nitrogen-containing organic molecules, boron-containing organic molecules, phosphorus-containing organic molecules, sulfur-containing organic molecules, and nitrogen-boron, sulfur-nitrogen or nitrogen-phosphorus containing organic molecules is used as a precursor, iron, cobalt, nickel and other transition metals or platinum, palladium, gold, silver and other precious metal salts are added, sintering is carried out by a microwave heating method, and thus the doped graphene or graphene-like product is obtained. The prepared hetero atom doped graphene or graphene-like product and the hetero atom doped graphene or graphene-like product loaded with iron, cobalt, nickel and other transition metals or platinum, palladium, gold, silver and other precious metals and alloys thereof can be used as a fuel cell catalyst.

The invention discloses a preparation method of a nitrogen-doped graphene loaded platinum nano-particle catalyst. The preparation method comprises the following steps of: firstly, preparing graphene oxide (GO); secondly, preparing polyaniline / graphene oxide (PANI / GO) through a liquid-liquid interface polymerization method; thirdly, drying the PANI / GO, transferring the dried PANI / GO into a tubular furnace, and performing high-temperature treatment for 2 hours at 800 DEG C to prepare NGs (nitrogen-doped graphenes); and finally, ultrasonically dispersing the NGs into an aqueous solution, uniformly mixing the NGs with chloroplatinic acid according to a certain mass ratio, slowly adding sodium borohydride (NaBH4) into the mixed solution, and performing magnetic stirring for 8 hours to prepare the NGs loaded platinum nano-particle catalyst (Pt / NGs) which takes the NGs as a catalyst carrier to uniformly load platinum nano-particles to the surfaces of the NGs without any chemical modification. The nitrogen atoms which are doped into molecular structures of GNs not only provide a large amount of active sites for PtNPs loading, but also enhance the interaction between the PtNPs and an NGs carrier and improve the catalytic stability and catalytic activity of a nano composite material.