2867 results about "Doped carbon" patented technology

The present disclosure relates to a carbon-based nanomaterial composition that may be formed from a gas mixture and a sulfur powder. The gas mixture may include a carbon based gas, an oxygen gas, and a hydrogen gas. The carbon-based nanomaterial composition may include sulfur doped nanospheres.

The invention relates to a preparation method and application of a manganese ion doped modified ferric sodium pyrophosphate positive electrode material, and belongs to the technical field of sodium ion battery positive electrodes. The preparation method comprises the following steps: adding a sodium source, a phosphorus source and a carbon source into ethanol, uniformly mixing to form a mixed solution, sequentially adding an iron source and a manganese source into the mixed solution, uniformly mixing to form slurry, and drying the slurry to obtain precursor powder; calcining in a protective atmosphere to obtain a manganese-doped carbon-coated ferric pyrophosphate sodium material; the calcining conditions are as follows: heating to the temperature of 300-350 DEG C at the heating rate of 2-3 DEG C / min, carrying out first-stage constant-temperature calcination for 2-3 hours, heating to the temperature of 500-550 DEG C at the heating rate of 5-8 DEG C / min, and carrying out second-stage constant-temperature calcination for 10-12 hours. By doping the manganese ions, the electronic conductivity and the ion diffusivity of the ferric sodium phosphate pyrophosphate composite material are improved, so that the discharge capacity of the ferric sodium phosphate pyrophosphate composite material at high rate is improved, and the battery has relatively high cycle stability.

The invention belongs to the technical field of crystal growth, and provides a low-resistivity silicon carbide single crystal growth method and system and a single crystal, silicon carbide powder is uniformly paved at the bottom of a graphite crucible, metal carbide material particles are uniformly paved on the surface of the silicon carbide powder, and silicon carbide seed crystals are adhered to the top of the graphite crucible; the graphite crucible is sealed, and the interior of the graphite crucible is vacuumized; heating the graphite crucible subjected to vacuumizing treatment, filling carrier gas into the graphite crucible, then slowly replacing the carrier gas with doped source gas, slowly increasing the growth pressure to a set pressure, and growing a buffer layer; after the growth of the buffer layer is completed, changing the growth condition to grow the heavily doped silicon carbide single crystal; and after the growth of the crystal is completed, cooling the graphite crucible subjected to vacuumizing treatment, so that the crystal is naturally cooled, and the low-resistivity silicon carbide single crystal is obtained. The doping concentration of the silicon carbide single crystal can be improved, and the resistivity of the silicon carbide material can be reduced.

The invention discloses a modified graphite felt electrode for an all-vanadium redox flow battery and a preparation method of the modified graphite felt electrode, and belongs to the technical field of redox flow battery electrode materials. The preparation method comprises the following steps: graphite felt electrochemical oxidation etching treatment; self-assembling a conductive layer on the oxidized and etched graphite felt to obtain the graphite felt attached with the conductive layer; and loading a metal and nitrogen-doped carbon (M and NC) nano catalyst layer on the graphite felt attached with the conductive layer to obtain the modified graphite felt electrode. Various properties of the graphite felt are comprehensively improved through matrix treatment, structure change and load catalysis, mild electrochemical oxidation etching is adopted, a carbon fiber structure is protected, a self-assembled net-shaped conductive layer forms a stable conductive channel, the specific surface area is remarkably increased, a nitrogen-doped carbon shell is adopted to wrap metal nanodots to form an M-NC catalytic layer, and the specific surface area is remarkably increased. The catalyst layer is not easy to dissolve out, the capacity fading rate is obviously improved, the loading capacity of the catalyst layer on the reticular structure conducting layer with a larger specific surface area is larger, and meanwhile, the process is simple and low in cost.

The present disclosure belongs to the technical field of back contact cells, and specifically relates to a back contact cell capable of reducing back parasitic absorption and a manufacturing method therefor. The back contact cell comprises a silicon wafer having a front surface and a back surface, and a first semiconductor layer provided on the back surface of the silicon wafer, the back surface of the silicon wafer being an inverted pyramid textured structure; the first semiconductor layer comprises a tunneling oxide layer and a first doped polycrystalline silicon layer; the inverted pyramid textured structure has alternate flat surfaces and pits sunken in the silicon wafer; the first doped polycrystalline silicon layer comprises a polycrystalline inner layer, a polycrystalline silicon middle layer and a polycrystalline silicon outer layer, the polycrystalline silicon inner layer, the polycrystalline silicon middle layer and the polycrystalline silicon outer layer all being doped with phosphorus, and carbon and / or oxygen; in the polycrystalline silicon inner layer, the polycrystalline silicon middle layer and the polycrystalline silicon outer layer, the amount of doped oxygen gradually decreasing, and the amount of doped carbon and the amount of doped phosphorus gradually increasing. The present disclosure can reduce the parasitic absorption of the back surface while ensuring passivation performance and conductivity, thereby helping to increase short-circuit current density and cell conversion efficiency.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a method for preparing a lithium ion battery negative electrode material from sulfur-doped black phosphorus-carbon. A carbon material and sulfur powder are subjected to ball milling, uniform mixing and vacuum high-temperature calcination to obtain a sulfur-doped carbon material; and uniformly mixing the sulfur-doped carbon material with black phosphorus, and performing high-energy ball milling in an inert atmosphere to obtain the sulfur-doped black phosphorus-carbon composite negative electrode material. According to the preparation method provided by the invention, the black phosphorus, the carbon material and the sulfur are well combined, so that the high capacity of the material is ensured, the structural stability of the composite material can be improved, the polarization of the material is reduced, and the cycling stability and the rate capability of the battery are improved.

The invention provides a ratio type molecular imprinting fluorescence sensing detection method based on a metal organic framework and nitrogen-doped carbon dots, the advantages of N-CDs, Eu-MOF and a molecular imprinting layer are fused, in the presence of target molecules, the blue fluorescence (430nm) of the N-CDs is effectively enhanced due to non-radiative recombination caused by the surface defect state of the CDs, and the red fluorescence (660nm) of the Eu-MOF remains unchanged. According to the ratio type molecularly imprinted fluorescent sensing detection method, while a fluorescent response signal is displayed, the color of the imprinted polymer changes along with different concentrations of the target molecules, and sensitive visual detection of the target molecules can be realized, so that specific sensitive detection of the target molecules in a complex sample is realized; the method has the advantages of high sensitivity, simplicity and convenience in operation, good reproducibility, strong anti-interference performance and the like. According to the method, rapid and sensitive detection of organophosphorus pesticides, toxic agents and other imprinted molecules can be realized by preparing imprinted polymers of different target molecules without fluorescence interference, and the method has a wide application prospect.

The invention discloses a modified carbon-coated sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material as well as a preparation method and application thereof, and relates to the technical field of new energy materials. The preparation method comprises the following steps: preparing MnFe-MOF from a manganese source, a first iron source and a first organic ligand under a hydrothermal reaction; a second iron source, the MnFe-MOF and a second organic ligand are subjected to a hydrothermal reaction, and MnFe-MOF / Fe-MOF is obtained; uniformly mixing with a sodium source and a phosphorus source, and sintering to obtain a positive electrode material; and carrying out high-temperature gas-phase etching treatment to obtain the fluorine-doped carbon-coated modified sodium manganese ferric phosphate pyrophosphate / sodium ferric phosphate pyrophosphate positive electrode material. The material disclosed by the invention has a coating modified structure, so that an interface side reaction caused by direct contact between sodium ferromanganese phosphate and an electrolyte can be effectively avoided, a manganese dissolution phenomenon is reduced, and the structural stability of the material is improved; and meanwhile, the material has high conductivity, excellent structural stability, excellent long cycle life and excellent rate capability.

The invention belongs to the technical field of batteries, and particularly relates to a lithium ferrite lithium supplement agent and a preparation method and application thereof. Compared with the prior art, a solid electrolyte coating layer is formed on the surface of the carbon-doped lithium iron oxide material through a low-temperature molten salt method, so that air can be effectively isolated, the air stability of the material is improved, the lithium removal phenomenon is reduced, and the structural integrity and lithium supplement performance of the material are kept; and the lithium ferrite lithium supplement agent combines the high theoretical lithium supplement capacity of Li5FeO4 and the excellent ionic conductivity of the solid electrolyte, so that the electrochemical performance of the material can be improved while the high lithium supplement capacity is maintained, and a new technical scheme is provided for commercial application of the high-energy-density lithium ion battery.

The invention discloses a graphite-doped negative electrode material as well as a preparation method and application thereof, and belongs to the technical field of rechargeable secondary battery negative electrode materials. The doped graphite negative electrode material comprises an inner core and a shell on the outer layer of the inner core, the inner core is an element-doped graphite-doped secondary particle; the doping mode of the doped graphite secondary particles is solid phase doping or liquid phase doping; the shell comprises an element-doped carbon coating layer formed by vapor deposition; and the total mass of the doped elements accounts for 0.5-10% of the mass of the doped graphite negative electrode material. According to the doped graphite negative electrode material provided by the invention, the graphite secondary particle core and the carbon coating layer are subjected to element doping treatment, the microstructure of graphite is improved by element doping, and active site defects are formed, so that the diffusion of a charge carrier is facilitated, and the dynamic performance of the material is improved; meanwhile, the graphite layer spacing is enlarged; the carbon coating layer isolates the graphite secondary particle inner core from being in direct contact with the electrolyte, so that the fast charging performance of the doped graphite negative electrode is comprehensively improved in an omnibearing and multi-angle manner.

The invention discloses a lithium ion battery modified graphite negative electrode material and a preparation method and application thereof, and belongs to the technical field of batteries, the negative electrode material is of a core-shell structure, an internal core is graphite particles, an external shell is a high electronegativity nonmetal / metal heteroatom co-doped carbon material of N, O, F and the like, the weight ratio of carbon doped in the shell part to graphite is X, and 2% < = X < = 20%. Compared with the prior art, the negative electrode material can form an SEI film which is more stable, compact and continuous and is rich in fluoride with high ionic conductivity, so that the SEI film can be effectively prevented from being broken and lost in the later charging and discharging process, and the service life of the negative electrode material is prolonged while the first-round coulombic efficiency of the negative electrode material is remarkably improved. And the cycle life and the high-current charge-discharge performance of the negative electrode material can be remarkably improved.

The invention discloses a high-entropy alloy / nitrogen-doped carbon nano catalytic material and a preparation method and application thereof.The nano catalytic material comprises a high-entropy alloy composed of five non-noble metals including Fe, Co, Ni, Cu and Mn and nitrogen-doped carbon synthesized with the assistance of MOF, the non-noble metal high-entropy alloy serves as a main body material, the nitrogen-doped carbon serves as a carrier material, and the nitrogen-doped carbon serves as a carrier material. A non-noble metal high-entropy alloy is loaded on nitrogen-doped carbon to construct a novel nano catalytic material, and the novel nano catalytic material is used for activating peroxydisulfate to remove antibiotics in a water body. The catalyst has the advantages of excellent chemical stability, good reusability and the like and is a novel nano catalytic material with efficient catalytic performance and environment-friendly characteristics, and the preparation method has the advantages of being simple in operation process, green, environmentally friendly, economical, feasible and the like and can be used for large-scale preparation.

The invention discloses a polypyrrole / cobalt / nitrogen-doped carbon composite material with a coaxial hollow structure and a preparation method thereof, and belongs to the technical field of advanced functional composite materials. The method comprises the following steps: firstly, synthesizing a hollow polypyrrole nanotube by a soft template method; secondly, cobalt / nitrogen-doped carbon is synthesized by adopting a template guiding method; and finally, secondarily coating the outer surface of the cobalt / nitrogen-doped carbon with a polypyrrole layer by adopting an in-situ oxidative polymerization method to construct the polypyrrole / cobalt / nitrogen-doped carbon composite material with a coaxial hollow heterostructure, and the polypyrrole / cobalt / nitrogen-doped carbon composite material has a coaxial sandwich structure: the inner core is a nitrogen-doped carbon hollow tube, the middle layer is a nitrogen-doped porous carbon matrix embedded with cobalt nanoparticles, and the outer surface of the cobalt / nitrogen-doped carbon composite material is a porous carbon matrix embedded with cobalt nanoparticles. And the outer layer is a conductive polypyrrole coating layer. The preparation method provided by the invention can successfully realize in-situ confinement growth and stable combination of ZIF-67, and has the advantages of high repetition rate, high yield and simple method; by adjusting the proportion of polypyrrole in the composite material, good impedance matching and large dielectric loss can be realized, and excellent electromagnetic wave absorption performance can be obtained.

The invention discloses a laser cladding preparation method for improving the wear resistance of a cladding layer by doping tungsten carbide. According to the method, cladding process parameters are preliminarily obtained based on finite element heat flow analogue simulation, cladding layer preparation is carried out, cladding quality characterization is carried out to obtain the optimal cladding process parameters, and finally the cladding layer with the wear-resistant characteristic is obtained. The method comprises the following steps: firstly, constructing a heat flow coupling three-dimensional model, carrying out grid division, establishing a heat source model, defining thermophysical parameters of tungsten carbide (10-15%) nickel alloy composite powder and a matrix, and determining simulated boundary conditions; setting a multi-factor process parameter combination to carry out numerical simulation calculation, and determining laser processing process parameters of laser power, scanning speed and light spot diameter; preparing a cladding layer on the surface of the nodular cast iron by using tungsten carbide (10-15%) nickel alloy composite powder through a laser cladding method; and carrying out microscopic morphology and microhardness experiments to carry out quality analysis verification on the cladding layer, determining the optimal process parameters of laser power, scanning speed and light spot diameter when the cladding layer has no obvious defect morphology and the hardness is higher than that of the raw material, and obtaining the laser cladding preparation method for improving the wear resistance of the cladding layer by doping tungsten carbide. The invention provides a new research method and a high-quality preparation approach for improving the wear resistance of the cladding layer by tungsten carbide, and can be widely applied to the fields of strengthening and repairing mining machinery, aerospace parts and the like.

The invention discloses a metal-doped carbon quantum dot as well as preparation and application of the metal-doped carbon quantum dot in a nano antibacterial agent, citric acid, urea and tea polyphenol are taken as precursors, metal salt is added, carbon dot synthesis and metal ion doping are synchronously completed in one step through a hydrothermal method, and the metal-doped carbon quantum dot is prepared; the surfaces of the metal-doped carbon quantum dots are negatively charged, and the metal-doped carbon quantum dots have peroxidase-like activity and catalase-like activity at the same time; the metal ions adopt any one of Fe < 3 + >, Cu < 2 + > and Ce < 3 + >; the metal-doped carbon quantum dots are in a sphere-like shape. The metal-doped carbon quantum dots prepared by the preparation method disclosed by the invention have peroxidase-like activity and catalase-like activity at the same time through precise doping of metal ions, and the two activities have a synergistic effect in an oral periodontitis microenvironment, so that a good antibacterial effect is achieved.

The invention discloses a MoS2-coated porous M-N-C monatomic catalyst and an application thereof in a lithium air battery, the MoS2-coated porous M-N-C monatomic catalyst is prepared by the following steps: chelating transition metal ions through a chelating agent, anchoring the transition metal ions on a porous carbon carrier, mixing the transition metal ions with a nitrogen source precursor, and calcining to obtain a material which takes porous nitrogen-doped carbon as a carrier and loads a transition metal monatomic M, thereby obtaining the MoS2-coated porous M-N-C monatomic catalyst. And wrapping the layered MoS2 nanosheets through a hydrothermal vulcanization method and high-temperature calcination to obtain the target catalyst material. The obtained composite material has higher mass transfer efficiency, has higher oxygen reduction activity and stability in acidic and alkaline media, has lower overvoltage, high specific discharge capacity and excellent cycle performance when being used as a lithium air battery catalyst, and has better research prospects.

The invention discloses a biochar / carbon nanotube / myristic acid composite phase change material as well as a preparation method and application thereof, and belongs to the technical field of heat storage. The meat biochar / carbon nanotube / myristic acid composite phase change material is prepared by adopting a vacuum impregnation method. The original biochar is modified by KOH, so that the specific surface area and pore volume of a sample are increased, the specific surface area of the modified KBC3 reaches 813.56 m < 2 > / g, and the loading capacity of the KOH modified biochar on MA is increased to 63%. The result shows that the MA sample is successfully loaded into the porous material, and the structure is kept intact. In order to further improve the loading rate and the leakage resistance of the phase change material, carbon nanotubes are doped in the KBC / MA phase change material, and when the loading rate of MA is improved to 75%, KBC1.5 / MA severely leaks in a shape stability performance experiment, and the mass loss rate reaches 8.5%. And KBC1.5 / CNT1 / MA only has little leakage in the thermal stability test process, so that the leakage resistance of the composite phase change material is greatly enhanced. Through BC modification and CNTs introduction, the heat conduction capability and the photothermal conversion capability of the composite PCMs are greatly improved.

On one hand, the invention relates to a sulfur-selenium doped carbon dot and Halicin synergistic antibacterial material which is prepared from an S, Se-CQDs solution and a Halicin solution in parts by weight as follows: 50-120 parts of the S, Se-CQDs solution, 0.1-0.3 parts of an EDC chemical reagent, 0.1-0.3 parts of an NHS chemical reagent, 125-300 parts of the Halicin solution and 12-35 parts of a NaOH solution, and on the other hand, the invention relates to a preparation method of the sulfur-selenium doped carbon dot and Halicin synergistic antibacterial material. The characteristics that the sulfur-selenium-doped carbon dots are uniform in size and easy to enter cells are utilized, the sulfur-selenium-doped carbon dots can cooperate with the Halicin to enter the cells to destroy the flow of protons on cell membranes, so that the sterilization and antibacterial effects are achieved, the sulfur-selenium-doped carbon dots and the Halicin synergistic antibacterial material can form a hydration layer on the surface of a wound by utilizing the oxidation resistance of the sulfur-selenium-doped carbon dots, and the antibacterial effect of the wound is improved. The adhesion of bacteria is prevented, so that the antibacterial effect is enhanced.

The invention relates to a preparation method of a copper-doped carbon nitride nano composite material and application of the copper-doped carbon nitride nano composite material in electrocatalytic carbon dioxide reduction. The preparation method comprises the following steps: firstly, preparing a carbon nitride precursor, taking salt of metal copper as a source of the metal copper to obtain a copper-doped carbon nitride nano composite material, and applying the copper-doped carbon nitride nano composite material to electrocatalytic reduction of carbon dioxide to obtain ethanol. Results show that in a wide voltage range, the catalytic performance of the catalyst is obviously improved, which is mainly characterized in that lamellar graphite carbon nitride is used as a substrate, existence of pyridine nitrogen is beneficial to activation of carbon dioxide to generate CO *, copper in a monatomic form can promote a C-C coupling process, and then a multi-carbon product ethanol is generated; and the lamellar morphology can utilize catalytic active sites to the greatest extent, so that the catalytic performance is greatly improved.

The invention provides an epitaxial growth process for improving doping uniformity of n-type doped silicon carbide, and relates to the technical field of semiconductors. The method is based on a chemical vapor deposition growth technology; 11 to 20 gt; the silicon carbide epitaxial growth is carried out by taking silicon carbide with a 4-degree silicon surface in the direction as a substrate, taking trichlorosilane (TCS) and ethylene (C2H4) as growth sources and taking ammonia gas (NH3) as a doping source. Ammonia gas is adopted as an n-type dopant, the decomposition efficiency of the n-type dopant is close to 100% at the temperature of 700 DEG C or above, and the energy of N-H bond breakage of ammonia gas molecules is 390 KJ / mo which is far lower than 946 KJ / mo needed by N-N bond breakage of nitrogen molecules. Therefore, compared with a traditional doping source such as nitrogen, the ammonia gas has higher doping efficiency, residues of excessive nitrogen-containing precursors in the reaction chamber can be reduced, the memory effect is reduced, and thus more excellent in-chip uniformity and stable inter-chip repeatability of the epitaxial wafer are obtained. The selection range of the doping source is widened, the accurate control of the doping concentration is realized, and the stability of the doping concentration in the continuous growth process is improved.

The invention relates to the technical field of electrode materials, in particular to a negative active material and a preparation method thereof, a negative pole piece, a secondary battery or capacitor and an electric energy storage system. The negative electrode active material provided by the invention comprises supported molybdenum disulfide and a carbon nanotube, the supported molybdenum disulfide comprises a reduced graphene oxide carrier and modified molybdenum disulfide loaded on the reduced graphene oxide carrier, the modified molybdenum disulfide comprises molybdenum disulfide and nitrogen-doped carbon, the molybdenum disulfide has a layered structure, and the nitrogen-doped carbon is inserted between layers of the molybdenum disulfide; wherein carbon nanotubes are filled between lamellas of at least part of the supported molybdenum disulfide; the reduced graphene oxide carrier and the carbon nanotubes are provided with etched holes. The negative electrode active material provided by the invention can effectively relieve the problems of volume change and structural collapse of the electrode material in the charge-discharge process, and improve the structural stability and conductivity, so that the capacity and cycle performance of the secondary battery can be effectively improved.

A supercapacitor including a negative electrode, a positive electrode, an electrolyte, and a separator. The separator is between the negative electrode and the positive electrode, and the electrolyte is present in and on the separator. The negative electrode and the positive electrode include a carbon material selected from a poly-anthraquinone sulfide activated carbon material and a poly-anthraquinone sulfide reduced activated carbon material.

The invention discloses a process for synthesizing ammonia by coupling low-temperature plasma with electro-catalysis in the field of clean energy and green chemical industry, which comprises the following specific steps: mixing air and water vapor, feeding the mixture into a dielectric barrier discharge reactor, filling the reactor with a multi-stage heterojunction gradient doped carbon coated catalyst, generating active gas containing NOx under pulse high voltage, and condensing and then entering an electrocatalytic reduction unit. And an electro-catalysis product enters a photo-thermal separation module integrated with a Janus type photo-thermal electrode, the temperature of the electrode is locally increased under visible light irradiation, NH3 desorption is promoted, and finally high-purity ammonia is obtained through polyimide membrane separation. The multistage heterojunction gradient-doped carbon-coated catalyst adopted in the process is prepared through multiple steps and contains gradient-doped boron, sulfur and Au nanoparticles on the surface, NOx adsorption, electron transport and sintering resistance are synergistically improved, and efficient ammonia synthesis under mild conditions is achieved.

The invention relates to a fluorine-nitrogen co-doped carbon-coated positive electrode material and a preparation method thereof, and the cycle performance of the positive electrode material is effectively improved by arranging a fluorine-nitrogen co-doped carbon-coated layer on the surface of a positive electrode active material. When the positive electrode material is applied to a battery system, the cycle life of the battery can be prolonged.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a nitrogen-doped carbon metal oxide composite material and a preparation method thereof, a negative electrode material, a negative electrode plate and a lithium ion battery. The nitrogen-doped carbon metal oxide composite material comprises Co2NiO4 with a hollow cubic structure, and a nitrogen element and a carbon element which are dispersed on the surface of the Co2NiO4. The material is good in conductivity, low in resistance and good in structural stability, volume expansion caused by Li < + > embedding in the circulation process can be relieved, the volume expansion effect in the material charging and discharging process can be inhibited, the electrode polarization effect can be reduced, and the charging and discharging specific capacity, the rate capability and the circulation stability of the material can be effectively improved.

The invention relates to the field of coating materials, and provides a high-wear-resistance stainless steel-based composite coating which is composed of dumbbell-shaped silver-doped silicon carbide, sea urchin-shaped titanium dioxide, 304 stainless steel powder, NiCrBSi nickel-based autolytic alloy powder and the like. The silver-doped silicon carbide is prepared through sol-gel, high-temperature carbonization and acid pickling, and the titanium dioxide filler is obtained through hydrothermal synthesis and calcination. Supersonic flame spraying deposition is adopted, the compactness and bonding strength are enhanced through laser remelting, and finally the wear resistance, the pollution resistance and the antibacterial performance are improved through vacuum annealing, mechanical polishing and hydrophobic coating modification. The design of dumbbell-shaped silver-doped silicon carbide and urchin-shaped titanium dioxide is adopted, high-wear-resistance, antibacterial and high-binding-force coating performance is achieved, the problems of wear resistance and bacteriostasis are solved, and the coating is suitable for the fields of cabinet door plates and the like.

The invention discloses a synthesis method and application of an iron-aluminum co-doped catalyst, and the synthesis method is characterized by comprising the following steps: S1, dissolving an aluminum metal salt and an iron metal salt in a beaker containing deionized water to obtain a solution A; s2, adding a phosphorus source into the solution A, and adjusting the pH to form a turbid liquid B; s3, biomass is added into the turbid liquid B to be stirred for 30 min, and a solution C is obtained; s4, adding a nitrogen source into the solution C, and drying the beaker in a water bath kettle; mixing the obtained dried product with an activating agent, and calcining under inert gas to obtain a catalyst crude product; and S5, grinding the catalyst crude product, washing with ethanol and deionized water, and carrying out vacuum drying to obtain the iron-aluminum co-doped catalyst. The preparation method is simple and low in equipment requirement. The invention discloses a novel nitrogen-doped carbon-coated zero-valent iron nanoparticle catalyst which can degrade pollutants by utilizing electron transfer of the pollutants and the catalyst under the condition of adding any oxidizing agent. Under the neutral room temperature condition, the catalyst has a very good removal effect on degradation of organic pollutants which are difficult to biodegrade, has very good stability, and is low in iron ion dissolution rate.

A nanocomposite electrode and a supercapacitor device including said nanocomposite electrode. The nanocomposite electrode includes a mixture of at least one binding compound, at least one conductive additive, and at least one molybdenum doped carbon material coated onto a substrate. The supercapacitor device includes two nanocomposite electrodes disposed facing one another, wherein the substrate of each nanocomposite electrode is coated with the mixture on an inside facing surface and the outer surfaces of the nanocomposite electrodes are not coated with the mixture, and the inside facing surfaces are separated by at least one electrolyte.

The invention provides a preparation method of a triazine / heptazine homojunction structure carbon-doped carbon nitride photocatalyst, which comprises the following specific steps: (1) placing mixed powder of melamine and 2, 4, 6-triaminopyrimidine in air, heating to 300-500 DEG C, and calcining for 2-6 hours to form a mixture of carbon-doped melamine and oligomer thereof; (2) placing the mixture obtained in the step (1) in water at 60-70 DEG C, performing ultrasonic dispersion, then slowly cooling to room temperature, oscillating for 12-36 hours, removing moisture through rotary evaporation, and further drying to obtain a solid supramolecular precursor; and (3) fully mixing the solid supramolecular precursor obtained in the step (2) with molten salt, calcining at 500-600 DEG C for 2-6 hours, cooling, fully washing with deionized water, removing mixed salt, separating solid residues, and drying to obtain the triazine / heptazine homojunction structure carbon-doped carbon nitride photocatalyst THCNx-t. The prepared carbon-doped carbon nitride photocatalyst is uniform in homojunction distribution, and has the characteristics of excellent photochemical properties, high photon-generated carrier separation efficiency and excellent photocatalytic benzyl alcohol selective oxidation performance.

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.