42results about How to "Increased electrochemical active sites" patented technology

The invention discloses a method for preparing a three-dimensional ordered porous lead dioxide membrane electrode by a template electro-deposition method. The method comprises the steps of preparing an antimony-doped tin dioxide intermediate layer on a porous titanium matrix via a sol-gel method, assembling a polystyrene sphere mono-dispersion serving a template agent to the intermediate layer via natural settlement, then preparing a lead dioxide active layer in the gap of the template agent via an electro-deposition method, and finally dissolving the template agent to obtain the lead dioxide membrane electrode with a porous structure. The lead dioxide membrane electrode has three-dimensional ordered porous structure, large specific surface area, many electrochemical active sites and large filtration flux, overcomes the defects that the traditional lead dioxide electrode has a compact structure and cannot be applied to a filtering electrochemical system, and has great application value in the electrochemical catalysis field.

The invention discloses a preparation method for nitrogen-doped graphene, which belongs to the technical field of carbon materials. The preparation method comprises the following steps: dispersing hard template montmorillonite in water to form a suspension and adjusting a pH value to 1 to 5; dissolving nitrogen-containing organic micromolecules which are used as a carbon source in the suspension and adding a polymerization initiator to induce polymerization of the carbon source; subjecting a polymerization product to filtering and washing and drying and calcining a filter cake; and removing the hard template by using hydrofluoric acid and carrying out repeated washing by using deionized water so as to obtain the nitrogen-doped graphene. According to the invention, the cheap nitrogen-containing organic micromolecules are used as the carbon source, the parallel structural and the nanometer spatial confinement effect of the hard template are employed, so the nitrogen-doped graphene with few defects and high quality is formed in carbonization of organic matters; and the method has the advantages of simple operation, safety, no toxicity, short reaction time and low cost.

The invention provides a preparation method of a composite electrode material. The preparation method comprises the following steps of performing mixing on soluble divalent nickel salt, soluble divalent cobalt salt, hexamethylene tetramine, lanthanum manganate and a solvent to obtain a mixed liquid; adding foamy nickel into the mixed liquid to be subjected to a hydrothermal reaction to obtain a precursor; and performing drying and annealing on the precursor in sequence to obtain the composite electrode material. A core-shell nanometer flower structure is grown on the conductive substrate foamynickel to be directly used as an electrode, so that use of a conductive agent and a binder in the conventional coating method can be avoided, and extra contact resistance is lowered; and through a synergistic effect of NiCo<2>O<4> and LaMnO<3>, the potential window is expanded and the energy density of a supercapacitor is improved.

The invention provides a preparation method of a biomass-based porous carbon material based on platanus orientalis seeds. The method specifically comprises the following steps that the platanus orientalis seeds are crushed and screened to obtain platanus orientalis seed powder; 5-10 parts by weight of the platanus orientalis seed powder, 5-10 parts by weight of solid alkali and 80-90 parts by weight of water are placed in a hydrothermal reaction kettle for pretreatment, the mixture is taken out and dried, and pretreated powder is obtained; the pretreated powder is subjected to carbonization treatment under the protection of inert gas, and a carbonized product is obtained; the carbonized product is sequentially subjected to acid washing and water washing and dried to constant weight, and the biomass-based porous carbon material is obtained. According to the preparation method, an alkali water heat treatment and high-temperature carbonization process is utilized, the preparation processof the biomass carbon material is simplified, and the use amount of an activating agent, namely strong base and the pollution to the environment are reduced. The obtained porous carbon material is excellent in performance when used as an electrode material of a supercapacitor, and has wide market application prospects.

The invention belongs to the technical field of electrocatalytic electrode preparation, and particularly relates to a three-dimensional ordered porous ruthenium dioxide membrane electrode and a preparation method thereof. The membrane electrode comprises a porous titanium matrix and a three-dimensional ordered ruthenium dioxide active surface layer, wherein the three-dimensional ordered rutheniumdioxide active surface layer has a communicated structure formed by three-dimensional ordered spherical piling, and a porous channel for liquid flowing is formed among the piled spheres. According tothe ruthenium dioxide membrane electrode, emulsion containing polystyrene microspheres is dripped to the surface of a titanium plate, hydrate ruthenium dioxide grows in gaps in a template by an electrodeposition method, and the template is removed through high-temperature sintering and is dehydrated to obtain the three-dimensional ordered porous ruthenium dioxide membrane electrode. The electrodecan overcome the defect that a traditional ruthenium dioxide electrode has a compact structure, the utilization rate of ruthenium dioxide is not high and ruthenium dioxide cannot applied to a filter type electrochemical oxidation system, the contact area, mass transfer efficiency and filtration flux can be greatly improved, and meanwhile, the preparation cost and operation energy consumption can be reduced.

The invention discloses a metal phthalocyanine-MXene composite material as well as a preparation method and application thereof. The method for preparing the metal phthalocyanine-MXene composite material comprises the following steps of: (1) mixing metal phthalocyanine with a first solvent to obtain a metal phthalocyanine solution, and adding the metal phthalocyanine solution into water to obtaina metal phthalocyanine nano structure; and (2) mixing the metal phthalocyanine nano structure, an MXene material and a second solvent to obtain the metal phthalocyanine-MXene composite material. The method is simple in technological process and good in repeatability; the adopted materials are easy to synthesize and low in price; large-scale preparation is easy; and commercialization of the materials and devices is facilitated. With the method adopted, the metal phthalocyanine nano structure can be introduced between MXene layers to serve as an interlayer spacer, therefore, the restacking effect of the MXene is effectively prevented, electrochemical active sites on the surface of the MXene are increased, the ion mobility in an electrochemical oxidation reduction process is remarkably enhanced, and then the electrochemical response to charge storage can be improved.

The invention discloses a preparation method of a sulfur, nitrogen and phosphorus codoped porous carbon material for a supercapacitor, and belongs to the technical field of a new energy source. Ginkgoleaves are used as a carbon source; deionized water is used for cleaning and removing surface impurities; after cleaning and drying, crushing is performed; the crushed ginkgo leaves and complex alkali metal hydroxide are uniformly mixed; in inert gas, the temperature is raised at a speed rate of 5 DEG C/min to reach activation temperature; heat insulation is performed for 2h to obtain an activated product; finally, the activated product is subjected to acid washing neutralization; deionized water is used for cleaning until a neutral state is reached; drying, grinding and sieving are performedto obtain the porous carbon material for the supercapacitor. The ginkgo leaves are used as raw materials for preparing the carbon material for the supercapacitor; the energy is saved; the environmentis protected; the process is simple; the cost is low; the sulfur, nitrogen and phosphorus self doping can be realized, so that the electrochemical active sites are increased; the wettability with electrolyte is enhanced; the porous carbon material has wide market application prospects when being used as a supercapacitor electrode material.

The invention discloses a method for preparing a MnO@ nitrogen-doped porous carbon nanocomposite, comprising the steps of dissolving trimesic acid in deionized water at 80 degrees centigrade; maintaining a constant temperature in a water bath for a period of time; then dissolving manganese acetate in the deionized water; pouring a manganese acetate solution into a trimesic acid solution and stirring the two solutions at a constant temperature; after a constant-temperature reaction for a period of time, washing and centrifuging the reaction product to obtain a metal-organic framework, namely Mn-BTC powder; drying the Mn-BTC powder in a constant-temperature drying oven; and calcining the Mn-BTC powder in an ammonia atmosphere to obtain the MnO@ nitrogen-doped porous carbon nanocomposite. TheMnO@ nitrogen-doped porous carbon nanocomposite exhibits excellent electrochemical performance in lithium ion storage, and the porous carbon can alleviate the volume expansion of manganese oxide in alithiation process.

The invention relates to the field of nano composite materials, in particular to an MXene and carbon nanotube composite hollow nanosphere as well as an autocatalytic preparation method and applicationthereof. The method comprises the following steps: taking positively charged melamine formaldehyde resin (MF) microspheres as a template; coating the MF microspheres with negatively charged MXene nanosheets through electrostatic interaction; preparing melamino-formaldehyde resin and MXene composite nano microspheres, loading cobalt ions onto the melamino-formaldehyde resin and MXene composite nano microspheres by using an impregnation method, and finally calcining at high temperature to remove the melamino-formaldehyde resin, thereby obtaining the MXene and carbon nanotube composite hollow nano spheres. In the high-temperature calcination process, cobalt nanoparticles are used as a catalyst for an MF decomposition product, and carbon nanotubes are generated through a chemical vapor deposition method, so that the MXene-CNT hollow nanospheres are obtained.

The invention belongs to the field of material preparation and particularly discloses a preparation method of an N-doped microporous carbon sphere ORR catalytic material. The preparation method comprises the following steps: (1) reacting a raw material solution containing pyrrole, formaldehyde and a structure regulator to obtain gel, wherein the structure regulator is water-soluble salt of zinc, and the concentration of Zn<2+> in the raw material solution is 1 to 5 mol/L; and (2), dehydrating the gel and then pyrolyzing the gel at a temperature not lower than 700 DEG C, so as to obtain the N-doped microporous carbon sphere ORR catalytic material. The invention also discloses the material prepared by the preparation method an application of the material in air batteries. The method disclosed by the invention can be used to prepare the ORR catalytic material with uniform spherical morphology, rich microporous structure and rich pyridine nitrogen-doped morphology, and the material has better ORR catalytic performance and anti-catalytic poisoning effect.

The invention provides a cathode catalyst for hollow nano water electrolysis, and a preparation method thereof. The method comprises the following steps: 1, adding potassium ferricyanide into a mixedsolution of a cobalt salt and sodium citrate according to the molar ratio of the cobalt salt to the potassium ferricyanide of (0.1-1): (0.2-0.5), then standing still, separating an obtained product, and sequentially washing and drying to obtain a prussian blue-like compound; and 2, carrying out annealing treatment on the prussian blue-like compound and NaH2PO2 under a protective gas according to amass ratio of (0.2-0.4): (1-2) to obtain the cathode catalyst for hollow nano-electrolysis of water. The method is uniform in reaction heating, simple and easy to operate and easy to control, the used raw materials are low in cost, the target product is easy to obtain, and the prepared catalyst is of a hollow structure and has excellent electrocatalytic activity and cathode reaction stability.

The invention belongs to the field of electrode material preparation, and particularly relates to a preparation method of a high-performance cabbage-shaped heterostructure electrode material. The method comprises the following steps of pretreating foamed nickel, dissolving 2-3 mmol of nickel acetate, 4-5 mmol of cobalt acetate, 2-3 mmol of sodium molybdate, 30-40 mmol of ammonium fluoride and 2-5 g of urea into 60-100 ml of water, stirring, reacting, cooling, cleaning and drying to obtain a prepared sample, dissolving 8-9 mmol of sodium sulfide in 60-70 ml of deionized water, magnetically stirring for 45 minutes, transferring the prepared sample into the solution, transferring into a reaction kettle, keeping the temperature at 80-90 DEG C for 12 hours, naturally cooling to room temperature, cleaning for three times by using absolute ethyl alcohol and deionized water, keeping the temperature of the prepared sample at 60 DEG C for 6 hours, and drying to obtain a finished product. The problems that the material morphology is not uniform, the synthesis method cannot be accurately controlled, the conductivity is poor, and the adhesion with a current collector is poor are solved.

The invention belongs to the field of material and energy electrochemistry and relates to a graded porous carbon material, a synthesis method thereof and application thereof serving as supercapacitorelectrode material. The graded porous carbon material has three-dimensional micro-nano pores. The synthesis method includes: utilizing porous mineral as a formwork and organic matter as a carbon source, mixing for carbonization, and activating to obtain the graded porous carbon material. A preparation method is simple and easy to implement, high in yield and low in cost, and the carbon material prepared by the method has high specific capacity and rate performance under high current density when being used as the supercapacitor electrode material.

The invention discloses a preparation method of a stacked NiO micro-nano material. The method comprises the following steps: first, blending terephthalic acid, nickel nitrate hexahydrate, N,N-dimethylformamide and water and then carrying out hydrothermal reaction; second, centrifuging, washing and drying hydrothermal reaction products to obtain a stacked Ni-MOFs micron material; and third, carrying out heat treatment on the stacked Ni-MOFs micron material to obtain a stacked NiO micro-nano material. The invention further discloses application of the stacked NiO micro-nano material. By the characteristic that a Ni-MOFs organic ligand functional group framework is easily degraded after heating heated in a high-temperature environment, the stacked NiO micro-nano material is prepared, by stacked morphology of the material, mutual supporting effect is provided for interlayer, the circumstance of collapse of the surface or the internal structure of the material is avoided, and the electrochemical property of the material is ensured; and the stacked NiO micro-nano material is applied to an anode material of a lithium ion battery, and the specific capacity of the lithium battery is improved.

The invention discloses a method for preparing a NiCo hydrotalcite/foamed nickel composite material by using Co-MOF as a sacrificial template, which comprises the following steps: preparation of a Co-MOF/foamed nickel template: respectively preparing cobalt nitrate and 2-methylimidazole into aqueous solutions, mixing, placing treated foamed nickel in the mixed solution, reacting at a proper temperature for a period of time, washing with water, and drying to obtain the Co-MOF/foamed nickel template; the reacted foamed nickel is cleaned with deionized water and dried in a drying oven, and a Co-MOF/foamed nickel template is obtained; the preparation process of the NiCo hydrotalcite/foamed nickel composite material comprises the following steps: preparing nickel nitrate into an aqueous solution, putting Co-MOF/foamed nickel into the nickel nitrate solution, and reacting for a period of time at a proper temperature to obtain the target product NiCo hydrotalcite/foamed nickel composite material. The prepared composite material can be directly used as an electrode material, use of a binder is avoided, a large number of active sites are increased, the electrode conductivity can be improved, ion transmission is promoted, and the capacitive performance of the composite material is improved.

The invention relates to the technical field of supercapacitor materials, and particularly discloses a biomass porous carbon material, a preparation method thereof and a supercapacitor. The porous carbon material is prepared from gold imperial chrysanthemum and comprises carbon and doping elements, the specific surface area ranges from 1580 m < 2 >/g to 2100 m < 2 >/g, the average pore size ranges from 2.70 nm to 3.40 nm, and the pore volume ranges from 0.80 cm < 3 >/g to 1.10 cm < 3 >/g. The doping elements in the biomass porous carbon material are doped in the carbon material in situ, so that the biomass porous carbon material has the characteristic of uniform distribution of the doping elements, a stable porous structure is formed, and the biomass porous carbon material has a relatively large specific surface area, so that the biomass porous carbon material shows relatively excellent capacitive performance.

The invention discloses a preparation method of a spirulina-based carbon material for a supercapacitor. The method comprises the following steps: according to the mass ratio of potassium oxalate to spirulina being 1.5:1, stirring spirulina and potassium oxalate in water until the mixture is uniformly mixed, carrying out centrifugal separation, collecting a precipitate, carrying out freeze drying, then calcining the dried product in an air atmosphere at 200 DEG C, and then carbonizing the dried product in an N2 atmosphere at 500-800 DEG C to obtain the three-dimensional porous spirulina-based carbon material. According to the prepared spirulina-based carbon material, a more effective folded porous carbon structure is generated through simple stirring and reaction of potassium oxalate, rich active sites and smooth diffusion channels are provided, the charge migration rate is increased, the volume effect in the electrochemical energy storage process is relieved, and the spirulina-based carbon material can be used as an electrode material to be applied to supercapacitors.