2559 results about "Temperature treatment" patented technology

The invention provides a method of producing a through-hole, a substrate used to produce a through-hole, a substrate having a through-hole, and a device using such a through-hole or a substrate having such a through-hole, which are characterized in that: a through-hole can be produced only by etching a silicon substrate from its back side; the opening length d can be precisely controlled to a desired value regardless of the variations in the silicon wafer thickness, and the orientation flat angle, and also regardless of the type of a silicon crystal orientation-dependent anisotropic etchant employed; high productivity, high production reproducibility, and ease of production can be achieved; a high-liberality can be achieved in the shape of the opening end even if temperature treatment is performed at a high temperature for a long time; and a high-precision through-hole can be produced regardless of the shape of a device formed on the surface of a substrate.

A method and corresponding software for automatically validating a computer platform thermal solution. An application program is employed to selectively execute thermal stress code to cause the platform's processor to dissipate an amount of power corresponding to a predetermined value, such as a thermal design power dissipation value specified by the processor's manufacturer. In one embodiment, tests are performed while operating at this power dissipation level to determine if a thermal overload condition exists, which may be determined by the processor's temperature, an indication that the processor is throttled, or a signal provided by the processor indicating the processor has detected a thermal overload condition. In another embodiment, a thermal resistance value is calculated based on the processor power dissipation, the temperature of the processor, and the ambient temperature of the test environment. In one embodiment the entire validation process is automatically performed by the application program without requiring any extraneous test equipment or temperature probes.

The invention surprisingly finds that when a suitable binder including a suitable filler is used during the high temperature treatment of a curing process, the coating materials of the invention change in such a manner that electrically conducting reactive layers are formed that allow welding and especially spot welding together with the metal substrate even after treatment at temperatures of more than 800 DEG C.

The present invention provides a method for dielectric passivating the surface of a solar cell by accumulation of negative fixed charges of a first type at the interface between semiconductor material and a passivating material. According to the invention the passivating material comprises an oxide system, for example a binary oxide system, comprising Al₂O₃ and at least one metal oxide or metalloid oxide which enhances the tetrahedral structure of Al₂O₃, for example, an (Al₂O₃)_x(TiO₂)_1-x alloy. In this way it is possible to combine the desirable properties from at least two different oxides, while eliminating the undesirable properties of each individual material. The oxide system can be deposited onto the semiconductor surface by means of a sol-gel method, comprising the steps of formation of the metal oxide and/or metalloid oxide sol and the aluminum solution and then carefully mixing these together under stirring and ultrasonic treatment. Thin films of the oxide system can then be deposited onto the semiconductor surface by means of spin coating followed by a temperature treatment.

The invention discloses a method for recovering polysilicon ingots, carborundum powder and polyethylene glycol from cutting waste mortar. The recovering method comprises the following steps shown as an attached diagram, wherein the high temperature purification comprises the following steps of: mixing the prepared silicon micro powder with a fluxing agent according to the weight ratio of 1: 0.5-5 into lumps, carrying out high temperature treatment in a high temperature vacuum furnace with the treatment temperature range of 1450-1800 DEG C and the treatment time range of 1-10h; and then carrying out directional solidification on melting-state high purity silicon subjected to the high temperature treatment to obtain the polysilicon ingots; wherein the fluxing agent is selected from one or any mixture of silica, alumina, calcium oxide, magnesium oxide, potassium oxide, sodium oxide, calcium fluoride, magnesium fluoride, sodium fluoride, sodium chloride, potassium chloride and calcium chloride. The invention has the advantages that: the yields of carborundum and polyethylene glycol are high and can reach more than 70-80 percent; and the recovered polysilicon ingots reach the purity of 6-7N and completely satisfy of the requirement for preparing silicon slices of silicon solar cell.

The invention provides a preparation method of a silicon/carbon multi-component composite negative electrode material. The preparation method comprises the following steps: (1) preparing a carboxyl carbon nano-tube by using acid and a carbon nano-tube, or preparing an aminated carbon nano-tube by using the carboxyl carbon nano-tube; (2) oxidizing the surface of nanometer silicon so as to generate a layer of silicon oxide, or aminating slightly oxidized nanometer silicon by using ammonia-containing organosilane under the condition of heating reflux; (3) adding the carboxyl carbon nano-tube and the aminated nanometer silicon, or the carboxyl carbon nano-tube and the slightly oxidized nanometer silicon to an organic carbon source-containing solvent, dispersing and carrying out spray drying-pyrolysis; (4) mixing a material obtained in the step (3) with asphalt, and sequentially carrying out low-temperature, constant temperature and high-temperature heat treatments, thus obtaining a secondary silicon-carbon nano-tube/amorphous carbon composite negative electrode material; and (5) carrying out airflow crushing, grading, adding to the organic carbon source-containing solvent, carrying out spray drying-pyrolysis or spray pyrolysis, and carrying out high-temperature treatment, thus obtaining the silicon/carbon multi-component composite negative electrode material. The silicon/carbon multi-component composite negative electrode material prepared by the method has the advantages of large reversible capacity, designable capacity, good cycle performance, high tap density and the like.

The invention discloses a preparation method of an anode material for a power lithium ion battery. The preparation method comprises the following steps: by adopting petroleum coke ground until the grain size is 1-6mu m, calcined petroleum coke or needle coke as a raw material, adding additives, adding a mixture to a reaction kettle to carry out first high-temperature carbonization coating under the protection of the inert atmosphere, then grinding the mixture with a grinder until the grain size is 5-13mu m, then carrying out superhigh-temperature graphitization at a temperature above 3200 DEG C, adding one or a mixture of petroleum asphalt, coal asphalt and resin to a material obtained after graphitization, and then enabling the mixture to enter a carburization furnace to undergo second coating under the protection of the inert atmosphere to obtain the anode material for the power lithium ion battery, namely a spheroidal artificial graphite material which is formed through bonding after being coated with granules and undergoes two-time coating and three-time high-temperature treatment. The preparation method has the advantages that the discharge rate property of the anode material is improved, the low temperature properties of the anode material are improved, and the latest requirements of the market for the product are further met.

The invention discloses a method for preparing a carbon/carbon-silicon carbide composite material for bearings. The preparation method comprises the following steps: preparing a carbon fiber integral felt of 0.15-0.30g/cm<3> from polyacrylonitrile preoxidized fibers through puncture carbonization, or preparing a non-woven cloth carbon fiber integral felt of 0.4-0.6g/cm<3> from non-woven cloth and a mesh tyre through puncture carbonization in an alternating lamination manner; preparing C/C porous preform with density of 1.35-1.75g/cm<3> by adopting a chemical vapor infiltration (CVI) and resin precursor infiltration and pyrolysis (PIP) comprehensive process, and performing a high-temperature treatment at 2,250-2,600 DEG C in the Ar gas protective atmosphere; and vacuumizing, then introducing Ar gas, heating to 2,200-2,350 DEG C to perform liquid silicon infiltration, and preserving heat for 1.5 hours. The method is a preparation method of the carbon/carbon-silicon carbide (C/C-SiC) composite material with little residual silicon and low abrasion rate for bearings.

The invention relates to a method for pretreating fibers, comprising the following steps of: performing surface activation on fibers by a dopamine hydrochloride biomimetic modification method, and then performing impregnation treatment on the fibers by using impregnation solution composed of rubber latex and phenolic resin, aiming to improve the interface adhesion property of the fibers with rubber so that the fibers are more suitable for tyres, conveyor belts, high-pressure rubber tubes and transmission belts. The method solves the experimental problem caused by high toxicity of isocyanate and avoids damage on the fibers caused by high-temperature treatment; and the process flow is simplified and the production cost is reduced.

The invention belongs to the technical field of nanometer material preparation, and relates to a method for loading nanocrystalline metal oxide or nanocrystalline metal materials by porous carbon. Urea derivatives, saccharides and metal salt can form the characteristics of even mixed solutions at certain temperature, the porous carbon is formed in situ after dehydration and carbonization, and then the nanocrystalline metal oxide or the nanocrystalline metal materials loaded by the porous carbon are prepared through high temperature treatment. According to the method, the raw material ratio, response time, heat treatment temperature and other synthesis condition are changed, and carrying type nanometer materials with the carrying amount, the size of the particle diameter, the crystalline phase and components simultaneously controllable can be obtained. The whole process has the advantages of being easy to operate, environmentally friendly, low in cost and the like, the obtained nanocrystalline metal oxide or nanocrystalline metal materials loaded by the porous carbon have wide application prospects in industrial catalysis, water treatment, electrochemistry and other aspects.

The invention discloses an energy storage battery management system. A distributed three-layer management system is adopted in the system, wherein the management system comprises a bottom BMU (Battery Measurement Unit), a middle BCMS (Battery Cluster Management System) and a top BAMS (Battery Array Management System). The bottom BMU comprises a voltage and temperature measuring module and a charging/discharging balancing module; the middle BCMS is the core of the battery management system and comprises a voltage temperature treatment module, a balance control module, a relay control module, an AD (Analog and Digital) collecting module and a core parameter calculating module; and the top BAMS comprises a battery information gathering module, a system alarm information treatment module, a BAMS-PCS (Battery Array Management System-Process Control System) communicating module and a BAMS-PCS-upper monitoring system communicating module. Information transmission in the three layers of structures in the system is realized by using a CAN2.0B communication protocol; and the communication between the BAMS and an energy conversion PCS system and an upper monitoring system is realized by using a Modbus TCP (Transmission Control Protocol). On account of the special requirement on the battery management system in the field of energy storage, the invention provides the energy storage battery management system which is high in reliability, complete in function, real-time and stable in communication and relatively complete in management system structure.

The invention discloses a preparation method for an ordered mesoporous carbon/tungsten carbide composite material and a supported catalyst thereof. In the method, an organic matter and a tungsten salt are separately used as a carbon source and a tungsten source, and the carbon source and the tungsten source are mixed with a surfactant; and a precursor of the ordered mesoporous carbon/tungsten carbide is synthesized by a solvent-evaporation induced self-assembly method, and then the precursor is subject to high-temperature treatment in the inert atmosphere to form the ordered mesoporous carbon/tungsten carbide composite material. The ordered mesoporous carbon/tungsten carbide composite material prepared by the method has the characteristics of high degree of order, narrow aperture distribution, large specific surface area (greater than 500 m<2>/g) and the like. The invention further comprises a supported catalyst prepared by supporting active components on the ordered mesoporous carbon /tungsten carbide composite material which is prepared by the method; and because of the synergistic effect and the structure effect of the ordered mesoporous carbon/tungsten carbide composite material, the catalyst has higher methanol electro-oxidation catalytic activity than a commercial carbon platinum-ruthenium catalyst.

The invention discloses a molybdenum disulfide-carbon hollow ball hybrid material. The molybdenum disulfide-carbon hollow ball hybrid material has a hollow ball structure; and the hybrid material formed by embedding a single layer of molybdenum disulfide nanosheet or a few of layers of molybdenum disulfide nanosheets into a carbon material is a shell layer of the hollow ball. The invention further discloses a preparation method of the molybdenum disulfide-carbon hollow ball hybrid material. The method comprises the following steps: with amino-modified silica particles as a template, coating the template with an organic pyrolytic carbon material and ammonium tetrathiomolybdate through solvothermal reaction; carrying out high-temperature treatment in an inert atmosphere; and finally removing a silicon dioxide template, so as to obtain the molybdenum disulfide-carbon hollow ball hybrid material disclosed by the invention. The initial lithium insertion capacity of the molybdenum disulfide-carbon hollow ball hybrid material disclosed by the invention is close to 1010mAh/g; and the specific capacity can still be kept at 662mAh/g after 40 repeated charge and discharge cycles.

The invention provides a treatment method of oily sludge, which comprises the steps of: introducing overheated vapor into a high temperature treatment groove to roast the oily sludge so as to evaporate the liquid containing oil and water in the oily sludge to gas; separating the solid granules from the oily sludge and contained in the gas in a gas-solid separator, and conveying the solid granules to a drying machine to be dried and burnt so as to be discharged; condensing the gas separated from the gas-solid separator to liquid state oil and water, separating the liquid state oil and water in an oil-water separator to be respectively recycled, wherein the oily sludge is introduced into the high temperature treatment groove in a pumping manner, the overheated vapor is introduced into the high temperature treatment groove by supersonic jet flow and is vertically collided with the oily sludge. The invention further provides a treatment apparatus of oily sludge for executing the method; the treatment method and treatment apparatus provided by the invention have the advantages of guaranteeing high crude oil recovery, and small water content and oil content of finally generated dry residues.

The invention discloses a pyrolysis amorphous carbon material and a preparation method and application thereof. The pyrolysis amorphous carbon material is shaped as particles, the average grain size of the particles is 1-100 micrometers, a d<002> value is between 0.35 nanometer and 0.44 nanometer, an L<c> value is between 0.5 nanometer and 4 nanometers, and an L value is between 3 nanometers and 5 nanometers. The preparation method comprises the following steps of: adding a hard carbon precursor and a soft carbon precursor into a solvent and fully mixing to obtain a slurry; drying the slurry and crosslinking and curing the slurry for 0.5 to 5 hours in an inert atmosphere with a condition of 200-600 DEG C; carrying out high-temperature treatment for 0.5 to 10 hours in the inert atmosphere with a condition of 1,000-1,600 DEG C; and cooling to obtain the pyrolysis amorphous carbon material. The material is wide in application, and particularly serves as an anode material of a sodium ion secondary battery or a lithium ion secondary battery.

The invention relates to a method for preparing a work hardening insulation quilt for a high temperature furnace, which comprises the following steps of: 1, cutting, pre-impregnating and airing a soft quilt; 2, adhering the soft quilt by using an adhesive; 3, pressing and curing for forming; 4, performing carbonization treatment; 5, performing high temperature treatment; 6, machining; 7, performing coating treatment; and 8, performing chemical vapor deposition treatment and high temperature treatment, or directly performing high temperature treatment to obtain the work hardening insulation quilt for the high temperature furnace. The method has the advantages of simple technological process and suitability for mass production; and the prepared work hardening insulation quilt has the heat conductivity of less than or equal to 0.5W/m.K, the ash content of less than or equal to 2,000ppm, high mechanical properties and high-temperature dimensional stability and excellent processability, does not generate volatile matters when used in the high temperature furnace, cannot pollute the product, and has important significance for prolonging the service life of the insulation quilt in the high temperature furnace.

The invention relates to the technical field of synthesizing of graphene materials and provides a preparation method of nitrogen-doped graphene. The preparation method includes: using an improved Hummers method to prepare continuous large-piece graphene oxide; using a hydrothermal method to prepare the graphene oxide into graphene of a porous three-dimensional structure; ultrasonically dispersing the graphene of the porous three-dimensional structure into an acid solution with the pH being 1-5, adding aniline, well mixing, adding ammonium persulfate, well mixing, and transferring the obtained mixed liquid into a teflon container for hydrothermal reaction so as to obtain a porous three-dimensional graphene-polyaniline compound; performing high-temperature treatment under nitrogen protection to allow polyaniline to decompose out nitrogen sources so as to obtain the nitrogen-doped porous three-dimensional graphene. The method has the advantages that the nitrogen-doped graphene with high nitrogen content can be prepared, the structure of the three-dimensional graphene can be kept, the obtained nitrogen-doped porous three-dimensional graphene is good in electrochemical performance and quite suitable for being used for producing a super capacitor, and the method is convenient to operate and beneficial to industrial popularization.

The present invention relates to a method for production of electrodes for Li-primary and Li-ion batteries based of using two types of binder. The first binder is soluble in organic solvent and second binder is insoluble in organic solvent during the process of slurry preparation. Combination of the slurry composition and conditions of the electrode temperature treatment decrease the cathode production complexity, improve electrochemical characteristics of the electrode, increase adhesion properties and flexibility of coating, and reduce the interface resistance between the current collector and electrode mass.

The invention belongs to the technical field of additive manufacturing, and relates to a hot isostatic pressing three-control method suitable for additive manufacturing parts. The method comprises the steps that design of the hot isostatic pressing treatment technology is firstly carried out according to the materials and defect conditions of parts, in order to prevent deformation of the parts in complex shapes, the low-temperature and high-pressure treatment technology is selected, and auxiliary tools are matched to guarantee the shapes and size precision of the parts. In addition, in the hot isostatic pressing treatment process, according to the requirement of the phase control technology of the parts, heat treatment is selected to be carried out while hot isostatic pressing high-temperature treatment is carried out, or heat treatment is carried out in the cooling process after hot isostatic pressing treatment is finished, phases and structures are regulated and controlled, and the additive manufacturing parts with the needed performance are obtained. Control over the shapes of the additive manufacturing parts, improving of the performance of the additive manufacturing parts and phase control of the additive manufacturing parts are combined, shape control, performance control and phase control are achieved in the short procedure in the hot isostatic pressing technology process, cost can be better reduced, and industrial production can be achieved.

HF-originated radicals generated in a plasma-forming chamber are fed to a treatment chamber via feed holes, while HF gas molecules as the treatment gas are supplied to the treatment chamber from near the radical feed holes to suppress the excitation energy, thereby increasing the selectivity to Si to remove a native oxide film. Even with the dry-treatment, the surface treatment provides good surface flatness equivalent to that obtained by the wet-cleaning which requires high-temperature treatment, and further attains growth of Si single crystal film on the substrate after the surface treatment. The surface of formed Si single crystal film has small quantity of impurities of oxygen, carbon, and the like. After sputtering Hf and the like onto the surface of the grown Si single crystal film, oxidation and nitrification are applied thereto to form a dielectric insulation film such as HfO thereon, thus forming a metal electrode film. All through the above steps, the substrate is not exposed to atmospheric air, thereby suppressing the adsorption of impurities onto the interface, and thus obtaining a C-V curve with small hysteresis. As a result, good device characteristics are obtained in MOS-FET.

The invention discloses a SiO2 antireflection thin film. The SiO2 antireflection thin film comprises a photovoltaic glass substrate, and a first SiO2 dense layer in the thickness of 10nm-30nm and a SiO2 nano hollow granular layer in the thickness of 50nm-300nm, which are sequentially coated on the photovoltaic glass substrate, as well as second SiO2 dense material filled in pores among SiO2 nano hollow granules in the SiO2 nano hollow granular layer; and the filling total amount of the second SiO2 dense material is equivalent to the amount of the SiO2 dense material in the first SiO2 dense layer in the thickness of 5nm-30nm. The thin film has excellent antireflection performance, resistance to wiping and durability. The invention further discloses a preparation method of the SiO2 antireflection thin film, and the preparation method comprises the following steps: preparing the first SiO2 dense layer on photovoltaic glass, further preparing the SiO2 nano hollow granular layer, filling the second SiO2 dense material and performing high-temperature treatment to obtain the SiO2 antireflection thin film. The method is simple to operate and suitable for industrial large-scale application.

The invention discloses a preparation method of an oil absorption material which is ultra-light in weight and has magnetic field response performance. The method comprises the following concrete preparation processes: dispersing magnetic nanoparticles, a porous material and a functional polymer into a dispersion medium; ultrasonically dispersing, and then drying by a freeze-drying method or a supercritical fluid drying method, and carrying out high-temperature treatment so as to obtain the magnetic oil absorption material which is very low in mass and has a porous structure. The method has the characteristics of being simple in preparation process, simple and feasible in reaction condition, and easy to achieve large-scale production; the prepared material can be applied to treatment of marine oil leakage, and separation of hazardous organic compounds in industrial sewage. The ultra-light magnetic oil absorption material floats on water to adsorb crude oil or organic matters when being used due to light weight, and quick magnetic separation and enrichment can be achieved after adsorption is ended.

The invention relates to a heat-resisting silica aerogel material and a preparation method thereof. SiO2 sol is prepared by adopting a sol-gel method, modified liquid is innovatively led to a supercritical drying process by ageing and solvent replacement through adopting a supercritical modification process, so as to obtain bulk aerogel which is high in mechanical strength and easy to process, and then the SiO2 aerogel of which linear contraction just is 5%, and the specific surface area can be up to 530m<2>/g after high-temperature treatment at 1000 DEG C can be obtained by high-temperature pretreatment at 800 DEG C and gas-phase modification of hexamethyldisilazane. By adopting the synthetic method, application of the SiO2 aerogel in high-temperature fields such as high-temperature catalysis, a catalyst carrier and high-temperature heat preservation and insulation is greatly facilitated.

The invention discloses a recovery method of anode materials for lithium-ion batteries, comprising the following steps: 1) stacking up pole pieces in a metal container in a dense manner and covering the surfaces of the pole pieces with a layer of metal foils, placing the pole pieces in a high-temperature furnace at 400-600 DEG C to be baked for 5-50min, so that the adhesives are decomposed and lose adhering effects and all the anode powder naturally sheds from the current collector; and drying the size at low temperature and then baking the size in the high-temperature furnace for certain time; and 2) sieving the mixture baked at high temperature and recovering the qualified anode powder. In the method, through high-temperature treatment of the pole pieces, the adhesives are decomposed and lose adhering effects and all the anode materials can naturally shed from the current collector, and through sieving and detection, the recovered anode powder is proved to have electrochemical performance similar to that of the raw materials and can be directly put on production.

The invention discloses a lithium ion battery cathode material and a preparation method thereof, which lower the cost of the lithium ion battery cathode material and improve the high-energy density thereof. The lithium ion battery cathode material takes more than one of natural crystalline graphite, natural cryptocrystalline graphite and natural crystalline vein graphite as matrixes, a non-graphitic carbon material is coated outside the matrixes, and the coated particles are compounded with a conductive material. The preparation method of the lithium ion battery cathode material comprises the following steps of mixing and drying a liquid phase, carbonizing, carrying out high-temperature treatment and compounding. Compared with the prior art, the graphite with lower carbon content is taken as a raw material to greatly reduce the raw material cost; by adopting a hot air drying mode, the preparation process is simplified and a coating layer is more solid and compact; and by adopting lower carburizing temperature and the temperature for high-temperature heat treatment, energy consumption is reduced, and product cost is further lowered.

A high-resistance silicon wafer is manufactured, in which a gettering ability and economical efficiency is excellent and an oxygen thermal donor is effectively prevented from being generated in a heat treatment for forming a circuit, which is to be implemented on the side of a device manufacturer. In order to implement the above, a high-temperature heat treatment at 1100° C. or higher is performed on a carbon doped high-resistance and high-oxygen silicon wafer in which specific resistivity is 100 Ωcm or more and a carbon concentration is 5×10¹⁵ to 5×10¹⁷ atoms/cm³ so that a remaining oxygen concentration becomes 6.5×10¹⁷ atoms/cm³ or more (Old-ASTM). As this high-temperature treatment, an OD treatment for forming a DZ layer on a wafer surface, a high-temperature annealing treatment for eliminating a COP on the surface layer, a high-temperature heat treatment for forming a BOX layer in a SIMOX wafer manufacturing process and the like can be used.

The present invention provides a ceramic filter to be used at a high temperature, and it contains a substance having preferential reactivity with an ash component contained in materials captured by the ceramic filter and not removed by a high temperature treatment such as combustion over the principal component of the ceramic filter; the reaction between said ash component being not removed by a high temperature treatment such as combustion of the filter and remaining accumulated and the filter component to cause melting of the filter being suppressed to attain a long period of service.

A novel method and system for storing high purity hydrogen into a salt cavern is provided. Particularly, the storage process involves storing high purity hydrogen into a salt cavern without seepage or leakage of the stored hydrogen through the salt cavern walls, by creating a permeation barrier along the salt cavern walls. The cavern pressure is monitored and controlled to ensure formation and maintenance of the permeation barrier. Optional temperature treatments may also be incorporated as desired.

A Platinum temperature sensor comprises a ceramic substrate and a platinum thin-film resistor applied to said ceramic substrate, a ceramic cover layer and a connecting layer generated from a ceramic green layer by pressure and temperature treatment. The ceramic cover layer is connected with the ceramic substrate in such a way via the connecting layer that the platinum thin-film resistor is sealingly encapsulated with regard to the environment.

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.