2242 results about "Solvothermal reaction" patented technology

The invention discloses a method for repair and regeneration of waste lithium iron phosphate battery cathode materials, which allows a lithium-source solution or a suspension to react with a recovered waste lithium iron phosphate battery material by a hydrothermal reaction or a solvent-thermal reaction, or allows the recovered waste lithium iron phosphate battery material to be processed by solid-phase ball-milling and calcination with the lithium source, performs liquid-phase or solid-phase direct lithium-supplementing repair of delithiated waste lithium iron phosphate, and then performs pertinent repair and regeneration by coating conductive agents or coating conductive agents and doping metal ions. The invention adopts a direct repair and regeneration method; the repaired waste lithium iron phosphate battery cathode material has excellent performance, and the specific capacity can reach above 90% of the specific capacity before discard; the method not only can effectively reduce environmental pollution of waste batteries, but also can make full use of waste resources and changes waste into valuables.

The invention takes ferric ion salt as raw material, which is taken solvent thermal reaction under 200-300deg.C to form Fe3O4 nanometer magnetic bead. At same reaction condition, through adding one or more kind of divalent soluble metal ion salt to make reaction with ferric ion salt and controlling the level of addition, the mol ration between the divalent soluble metal ion salt and ferric ion, the ferrite nanometer magnetic bead and the compound ferric ion nanometer magnetic bead are formed.

The invention discloses a modulating method of LiFePO4 particle shape, which comprises the following steps: blending one or more composition with lithium ion, ferric ion and phosphate radical ion; adding solvent and certain quantity of crystal growing inhibitor; proceeding solvent heat reaction under certain temperature; washing; filtering; drying; sintering to improve crystallizing property; obtaining the product with regular shape and size.

The invention provides an electrocatalyst with a cobalt-based multi-stage nano-composite structure for oxygen production by electrolysis of water and a preparation method of the electrocatalyst. The preparation method comprises the following steps: dissolving cobalt nitrate hexahydrate, urea and ammonium fluoride in deionized water to obtain a precursor solution; transferring the precursor solution into a hydrothermal reactor; adding carbon fiber paper; enabling basic cobalt carbonate nanowires to grow on the carbon fiber paper through solvothermal reaction; after finish of reaction, naturally cooling; then taking out a product; washing and drying to obtain a carbon fiver paper loaded basic cobalt carbonate nanowire composite structure; by taking powdered sulfur as the raw material, preparing a carbon fiber paper loaded cobalt sulfide nanowire composite structure through low-temperature sulfuration reaction under the condition of an inert gas; and finally, electroplating the surface of the carbon fiber paper loaded cobalt sulfide nanowire composite structure with a layer of cobalt hydroxide nanosheets by use of the electrochemical deposition method so as to obtain the electrocatalyst with the cobalt-based multi-stage nano-composite structure for oxygen production by electrolysis of water. As the sulfide and the hydroxide of transition metal cobalt are adopted as the catalyst, in comparison with noble metals, the cost of the catalyst is lowered.

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 discloses a magnetic biochar adsorbing material and a preparation method thereof. The preparation method comprises the following steps: (1) preparation of biochar: by using powder obtained by treating plant biomass as a raw material, roasting under oxygen-free conditions to obtain porous biochar; (2) preparation of ferric iron precursor liquid: by using ethanediol as a dispersing agent, adding a solid-state ferric iron salt, continuing adding sodium acetate and a surfactant into the ethanediol, and stirring to form a disperse system which is the ferric iron precursor liquid; and (3) solvothermal reaction: uniformly mixing the biochar and ferric iron precursor solution to obtain a mixture, putting the mixture into a teflon hydrothermal reaction kettle, and carrying out solvothermal reaction to obtain the magnetic biochar adsorbing material. The pretreatment technique of the key biomass raw material and the specific conditions of solvothermal reaction in the preparation method are improved, thereby effectively solving the problem of poor connection stability between the magnetic biochar material magnetic particles and biomass.

The invention discloses a three-dimensional porous cobalt-based/graphene composite material and a preparation method thereof. The composite material mainly comprises a cobalt-based material and graphene, wherein the graphene forms a porous three-dimensional conductive network; and the cobalt-based material is coated in the conductive network to form the three-dimensional porous cobalt-based/graphene composite material. The preparation method comprises the following steps of: dispersing the graphene and a cobalt salt precursor in a solvent by adopting a solvothermal in-situ one-step synthesis method; and placing in a reaction kettle for carrying out solvothermal reaction, freezing and drying to obtain the three-dimensional porous cobalt-based/graphene composite material. The composite material is used in a lithium ion battery, so that a constant-current charging and discharging test is carried out when the current density is as high as 6400mA/g, and reversible capacity after 30 circulations is still stabilized to 400mAh/g or higher. The three-dimensional porous cobalt-based/graphene composite material has the advantages of being cheap and easily available in material, low in cost, high in yield, simple and safe in operation process, environment-friendly, stable in product structure and suitable for large-scale industrial production.

The present invention relates to a transition metal-doped carbon fluorescent quantum dot preparation method, which comprises: dissolving a metal chelating agent and a transition metal salt in an organic solvent, carrying out a solvothermal reaction, and carrying out concentration purification after the reaction to prepare the transition metal-doped carbon fluorescent quantum dots having good water solubility. According to the present invention, the operation of the method is simple, the metal ion doping on the carbon fluorescent quantum dots can be achieved without harsh reaction conditions or large instruments, such that the characteristic that the long wavelength fluorescence emission is not easily achieved by the general carbon dots can be achieved; the obtained carbon fluorescent quantum dots have characteristics of good water solubility, wide fluorescence emission range, and maximum emission wavelength change along with concretion change; and with the characteristics of the preparation method, the prepared transition metal-doped carbon fluorescent quantum dots provide great application values in the fields of biological labeling sensing and medical imaging, photoelectricity, light-emitting device preparation, and the like.

The invention relates to a molybdenum disulfide/carbon black composite hydrogen-evolution electrocatalytic material and a preparation method therefor and belongs to the field of electrocatalytic hydrogen evolution. According to the preparation method, firstly, a carbon black oxide with low degree of oxidation is prepared by adopting an improved Hummer method; and then, the molybdenum disulfide/carbon black composite hydrogen-evolution electrocatalytic material is prepared through one-step solvothermal reaction at the temperature of 220 DEG C in a manner of taking sodium molybdate crystals as a molybdenum source, taking sulfourea as a sulfur source and taking dimethylformamide as a solvent. According to the method provided by the invention, the carbon black oxide with low degree of oxidation is simple in preparation process and high in yield; the molybdenum disulfide/carbon black composite hydrogen-evolution electrocatalytic material is prepared by adopting a simple, convenient and mild one-step solvothermal method, the cost is low, the repeatability is high, and large-scale synthesis is facilitated. When the molybdenum disulfide/carbon black composite hydrogen-evolution electrocatalytic material is applied to electrocatalytic hydrogen evolution reaction, excellent catalysis performance is shown, the reduced current density reaches 25.0mA/cm<2> when tested overpotential is 200mV, and the reduced current density reaches 36.2mA/cm<2> when tested overpotential is 226mV; the molybdenum disulfide/carbon black composite hydrogen-evolution electrocatalytic material has good electrocatalytic stability.

The invention discloses a preparation method of a metallic oxide/N-doped carbon nano tube composite material. The preparation method comprises the following steps of: (1) ultrasonically dispersing an N-doped carbon nano tube in a mixed solution of water and alcohol to obtain a solution A; (2) under the condition of stirring, dripping a solution B into the solution A, and stirring to obtain a mixed solution, wherein the solution B is water and/or alcoholic solution containing metal ions; and (3) carrying out solid-liquid separation on the mixed solution, and washing, drying and roasting to obtain the metallic oxide/N-doped carbon nano tube composite material. The invention also provides the composite material obtained through the method and an application thereof. According to the preparation method disclosed by the invention, as a method of solution phase synthesis under the condition of room temperature is adopted, hydrothermal reaction and solvothermal reaction with high temperature and high pressure are avoided, and the composite material with tighter combination of the metallic oxnide and the /N-doped carbon nano tube can be obtained. By adopting the preparation method, the preparation cost is low, the operation is simple, the preparation condition is mild, and the reaction period is also short.

The invention discloses a preparation method of a metal doped lithium manganese phosphate/graphene/carbon composite material. By adopting the method, the graphene is added in the preparation process of the lithium manganese phosphate to replace partial conductive carbon black; and a precursor which is a mixture of three solutions is transferred to a reaction tank and is subjected to solvothermal reaction at 160-300 DEG C for 1-20 hours to obtain the graphene in-situ composite lithium manganese phosphate material. According to the preparation method disclosed by the invention, the surface-contact compounding of graphene and lithium manganese phosphate is achieved by taking advantage of the flexibility characteristic of graphene, and the electronic conductivity of the lithium manganese phosphate is improved by taking advantage of the extremely high conductivity of graphene. By adopting the preparation method disclosed by the invention, not only is the intrinsic electronic conductivity of the composite material improved, but also a graphene film layer with extremely high conductivity is uniformly coated on the surface of the lithium manganese phosphate material, the graphene and the conductive carbon black together form a three-dimensional conductive network, and therefore the electrochemical performance of the lithium manganese phosphate material is obviously improved, and the composite material can be used as the anode material of a lithium ion battery.

A spinel-type lithium titanium oxide/graphene composite and a method of preparing the same are provided. The method can be useful in simplifying a manufacturing process and shortening a manufacturing time using microwave associated solvothermal reaction and post heat treatment, and the spinel-type lithium titanium oxide/graphene composite may have high electrochemical performances due to its excellent capacity and rate capability and long lifespan, and thus be used as an electrode material of the lithium secondary battery.

The invention discloses a method for preparing grapheme/ ceramic nanocrystalline particle composite material with an electrospinning-hydrothemal method. The method comprises the following steps: firstly, preparing ceramic/ polymer composite fiber by electrospinning; then, dissolving the composite fiber into a solvent for dissolving polymers; dismembering the fiber into tiny ceramic nanocrystalline seeds while the polymers in the composite fiber are dissolved; then, adding graphene oxide; carrying out hydrothermal or solvothermal reaction; and after reaction ends, adding a reducing agent to reduce the graphene oxide into grapheme. The ceramic/ polymer composite fiber is weaved by the electrospinning, and the hydrolysis speed of the metallorganics of a ceramic material precursor is controlled by controlling the moisture, electrospinning flow rate and the like in the electrospinning environment. The electrospinning method and the hydrothemal method are both simple and easy to implement and can be used for industrially producing and preparing nanofiber materials. The combination of the electrospinning method and the hydrothemal method creates convenience for industrial production of materials.

The invention relates to a preparation method of a foamed nickel composite material. The method comprises the following steps that oxidized graphene and a surfactant are added to a water and methanol mixed solution, and ultrasonic processing is carried out to obtain a oxidized graphene solution; nickel nitrate and cobalt chloride are added into the oxidized graphene solution and stirred and mixed to form a uniform suspension; and the uniform suspension is poured into a hydro-thermal reactor kettle, foamed nickel is immersed into the suspension, solvothermal reaction is carried out at 100-200 DEG C, the oxidized graphene is changed to graphene by reduction while nickel and cobalt hydroxide is generated at the surface of the foamed nickel in situ, and thus, the foamed nickel composite material whose surface is covered with a graphene and nickel-cobalt hydrotalcite like layer is obtained. The invention also relates to the obtained foamed nickel composite material and application thereof. The preparation method is simple, easy to control and low in cost, and the obtained foamed nickel composite material which serves as electrode material of a super capacitor has higher specific capacitance and high cycle stability.

The invention discloses a method for preparing a multiwall carbon nanotube-supported titanium dioxide catalyst, which belongs to the field of photochemical catalyst materials. The method comprises the following steps: adding multiwall carbon nanotubes and titanium sulfate into methanol respectively, and dispersing by ultrasonic waves and magnetic stirring; performing a solvothermal reaction, namely preparing a nano composite material by a solvothermal process to obtain the multiwall carbon nanotube-supported titanium dioxide catalyst; repeatedly washing the multiwall carbon nanotube-supported titanium dioxide catalyst, and drying under vacuum to obtain supported catalyst solid powder; dispersing the solid powder by ultrasonic waves and magnetic stirring, and preparing TiO2/MWCNT by a hydrothermal process; and repeatedly washing the obtained TiO2/MWCNT to obtain the multiwall carbon nanotube-supported titanium dioxide catalyst. In the TiO2/CNT prepared by the method, the TiO2 is selectively and uniformly loaded on the surface of CNT. The method combining the solvothermal and hydrothermal processes has the advantages of simplicity, high maneuverability and the like.

Disclosed in the invention is a preparation method of a Ni-MOF electrode material. A nicdel nitrate aqueous solution with the total concentration of 0.0075 to 0.43mol/l is added into a PTA/DMF solution with the total concentration of 0.005 to 0.03 mol/l, wherein the adding speed is 2 to 5ml/min and the volume ration of the nicdel nitrate aqueous solution to the terephthalic acid solution is 1.5-3 :1; after dissolution stirring of 1 to 2 hours, a precursor solution is obtained; solvothermal reaction is carried out on the precursor solution for 12 to 48 hours in a hydro-thermal kettle with the temperature of 120 to 200 DEG C, centrifugal washing and filtering are carried out on an obtained green precipitate respectively by DMF and absolute ethyl alcohol, and drying is carried out under the temperature of 80 DEG C, thereby obtaining a Ni-MOF electrode material. According to the preparation method, the specific capacitance of the material can be up to 1500F/g; after 3000-times charging and discharging circulation, 90% of specific capacitance still can be kept. The method is simple and can be controlled easily; the conditions are mild; and the production cost is low.

The invention discloses a nanometer material with controllable particle sizes and silicon dioxide hollow spheres and a method for preparing nanometer material. TEOS (tetraethyl orthosilicate) is used as an organic silicon source, CTAB (cetyl trimethyl ammonium bromide) is used as a structure directing agent, water, ethyl alcohol and cyclohexane are used as solvents, and PVP (polyvinyl pyrrolidone) is used as a stabilizer. The method includes carrying out heat reaction by the aid of the solvents to form precursors of the SiO2 hollow spheres; calcining the precursors and removing organic matters so as to obtain the SiO2 hollow spheres. The nanometer material and the method have the advantages that the silicon dioxide hollow spheres prepared by the aid of the method are excellent in dispersibility and have the adjustable particle sizes (of 220-430 nm), large pore diameters (of 10-12 nm) and uniform shell thicknesses, and cavities are large and can be used for storing large quantities of guest molecules; the nanometer material is high in chemical stability and packaging capacity and can be widely applied to the fields of enzymatic catalysis, substance adsorptive separation and the like; the method includes simple synthesis processes, is clean and is free of pollution and low in cost, and preparation procedures are good in repeatability.

The invention discloses a preparation method of an MIL-53(Fe)/g-C3N4 nanosheet composite photocatalysis material, and belongs to the field of preparation of photocatalysis materials. The preparation method comprises the following steps: carrying out a copolymerization reaction on urea used as a precursor at a high temperature to synthesize g-C3N4, carrying out ultrasonic peeling on the g-C3N4 in order to obtain nanosheets, mixing the nanosheets with an MIL-53(Fe) precursor, and carrying out a solvothermal reaction to obtain the MIL-53(Fe)/g-C3N4 nanosheet composite photocatalysis material. The above catalyst has the advantages of high photocatalysis activity, environmental protection, good reusability, realization of high-efficiency degradation of heavy metal Cr (VI) pollutants in water under a visible light condition, and wide application prospect.

The invention discloses a method for controlling morphology and performance of a ferriferrous oxide and belongs to the technical field of inorganic materials. The method comprises the following steps of: dissolving ferric trichloride hexahydrate in ethylene glycol to prepare a solution of which the ferric trichloride concentration is 0.15-0.35mol/L; then, adding urea and a surface active agent; fully dissolving to obtain a homogeneous solution; transferring the homogeneous solution into a high-pressure reaction kettle with a polytetrafluoroethylene lining; performing a solvent thermal reaction at the temperature of 170-230 DEG C for 6-72 hours; performing centrifugal separation after the reaction is ended; washing deposits by using deionized water and alcohol; and then, drying in a drying oven to obtain a finished product. The method for controlling the morphology and the performance of the ferriferrous oxide has the advantages that the production cost is low; the preparation technology is safe and simple; the product controllability is strong; and toxic and harmful substances are not generated in the preparation process. The obtained ferriferrous oxide is high in purity and centralized in particle size distribution, and the morphology can be mutually converted among a spherical structure, a microporous structure and a hollow structure.

The present invention discloses a phenyl triazine ligand that is used for the complexes of a metal organic framework and has a structural formula as shown in the formula (1). In the formula, R1 is carboxyl, hydrogen or methyl; R2 is hydrogen, methyl or carboxyl. At first, the derivative of aminobenzoic acid is used for synthesizing the aromatic nitrile intermediate; then the aromatic nitrile intermediate has trimerization reaction to prepare the carboxyl-containing triazine ligand. The synthetic method has the advantages of simple process, low cost, high yield, easily available raw materials and mild reaction conditions. The phenyl triazine ligand can coordinate with metal ions through the thermal reaction of the solvent so as to form the complexes of the metal organic framework. And the phenyl triazine ligand can practically applied in the small-molecule detection, catalysis, hydrogen storage and other fields.

The invention discloses a preparation method of a metal-organic framework material for adsorbing separation of carbon dioxide/ methane. The preparation method comprises the following steps of: (1) mixing 0.46-1.16mol/L cupric nitrate water solution and 0.23-0.58mol/L trimesic acid ethanol solution, fully stirring, then adding into a stainless steel reaction kettle provided with a polytetrafluoroethylene inner liner for sealing, and carrying out solvent thermal reaction while controlling the crystallization temperature to be 60-150 DEG C and the crystallization time at 12-24h; (2) opening the stainless steel reaction kettle, filtering, sequentially washing by methyl alcohol and deionized water, and drying at the temperature of 80-105 DEG C to obtain blue crystal; and (3) vacuumizing the blue crystal at the temperature of 150-200 DEG C to obtain the Cu-containing metal-organic framework material.

The invention provides high-conductivity aluminum-doped nano-zinc oxide powder and a preparation method thereof. The method of the invention comprises the steps that aluminum-doped zinc oxide nanocrystals are first prepared by solvothermal reaction and then sintered in the atmosphere of hydrogen to obtain nanometer-degree quasi-spherical conductive powder. The conductive powder is white and slightly gray and is non-toxic, light in weight and environment-friendly and also has less conglobation, good dispersity and repeatability and uniform size distribution; in addition, the particle size of the powder synthesized in different solvents is different and the minimum resistivity of the powder can reach 15 Omega cm and can be suitable for the various demands of products. The preparation method of the invention is simple in operation, short in period and low in cost, needs no surface active agents and templates and can be applied to mass production. The nanometer-degree conductive powder obtained by utilizing the method can be taken as conductive filler to be widely applied to fields such as paints, rubber, plastics and fibers, etc., for carrying out electrostatic prevention and electromagnetic shielding.

The invention discloses a ternary positive-electrode material prepared by a solvothermal method and a preparation method thereof. The preparation method includes: dissolving nickel cobalt manganese salt in a solvent, adding a surfactant and hydrolysis auxiliaries, sufficiently stirring, transferring into a reaction kettle, performing solvothermal reaction under certain temperature for 2-24 hours,cooling to room temperature, using a suction filtration method to separate out a nickel cobalt manganese ternary product, washing, drying, and pre-calcining in air to obtain a precursor; grinding andmixing the precursor and a lithium compound, and calcining to obtain the ternary positive-electrode material. The ternary positive-electrode material and the preparation method thereof have the advantages that the ternary oxide precursor prepared by the solvothermal method is small in particle size, uniform in particle distribution and controllable in morphology as compared with a ternary precursor prepared by a conventional precipitation method, so that the finally prepared ternary material is small in granularity, uniform in particle size distribution and controllable in morphology and has excellent electrochemical performance, and the capacity and stability of the prepared ternary material are better than those of a ternary positive-electrode material prepared by the precipitation method.

The invention discloses a preparation method of a skutterudite group thermoelectricity lump material, which adopts the combination of solvent thermosynthesis and vacuum melting. In the skutterudite MSb3, M equals to Co, Rh, and Ir, comprising the skutterudite MSb3; M bits or Sb bits-doped MSb3; Ag, Cu, Zn, Cd, Pb, Sn, Ga or In-filled MSb3; doped and filled MSb3 and MSb3 which is compounded with a second phase. The preparation method comprises the steps of: material blending, thermal reaction of the solvent, washing, thermal treatment and sealing melting. The invention discloses a preparation method of a skutterudite group thermoelectricity lump material compounded with the second phase, when adopting the method, second phase nano powder such as ZrO2 with the mass percentage of 0.05 percent to 5 percent is added for supplement in the step of the material blending. Compared with the existing commonly used spark plasma sintering or hot pressed sintering after simple substance mechanical alloying, or the plasma sintering or the hot pressed sintering after long-time high temperature solid phase reaction of the simple substance materials, the obtained materials are more compact and lower in cost.