3168 results about "Hydrothermal treatment" patented technology

The invention belongs to the fields of material synthesis and energy technology, and especially relates to a graphene/metal oxide composite cathode material for lithium ion batteries and a preparation method thereof. Grapheme is dispersed into various metal oxide precursor salt solutions; a graphene/metal oxide compound is obtained directly by a hydrothermal method, or an graphene/metal oxide compound is obtained by a liquid in-situ polymerization method or a coprecipitation process; and the graphene/metal oxide compound is obtained by heat treatment or hydrothermal treatment. In the invention, the novel three-dimensional composite cathode material of graphene-coated metal oxide or graphene-anchored metal oxide is prepared by carrying metal oxide particles with graphene as a carrier. The obtained composite material can be used as a lithium ion battery cathode, which has a high specific capacity, excellent cycle stability and rate capability, and is expected to be used as a lithium ion battery cathode material with a high energy density and a high power density.

The process for preparing tubular titanium oxide particles comprises subjecting a water dispersion sol, which is obtained by dispersing (i) titanium oxide particles and/or (ii) titanium oxide type composite oxide particles comprising titanium oxide and an oxide other than titanium oxide in water, said particles having an average particle diameter of 2 to 100 nm, to hydrothermal treatment in the presence of an alkali metal hydroxide. After the hydrothermal treatment, reduction treatment (including nitriding treatment) may be carried out. The tubular titanium oxide particles obtained in this process are useful as catalysts, catalyst carriers, adsorbents, photocatalysts, decorative materials, optical materials and photoelectric conversion materials. Especially when the particles are used for semiconductor films for photovoltaic cells or photocatalysts, prominently excellent effects are exhibited.

Disclosed is a hydrothermal treatment process for conversion of a carbon-based energy carrier material. The process comprises a step for sensitizing or activating the carbon based energy carrier material to increase its susceptibility to hydrothermal conversion. As a result of the sensitization step, the hydrothermal conversion step itself may be carried out under relatively mild conditions.

The process comprises the steps of sensitizing the carbon-based energy carrier material to increase its susceptibility to hydrothermal conversion; and subjecting the sensitized carbon-based energy carrier material to hydrothermal conversion at a temperature of less than 300 degrees centigrade in a hydrothermal treatment reactor.

The invention discloses microcrystal NaY-type molecular sieves and a preparation method thereof. In the microcrystal NaY-type molecular sieves, the molar ratio of SiO2 to Al2O3 is 4.0 to 6.0, and the average particle size is 100 to 700 nanometers. The microcrystal NaY-type molecular sieves are prepared by a method combining low-temperature synthesis directing agent, low-temperature synthesis gel and two-stage variable-temperature dynamic crystallization. The NaY-type molecular sieves have a relative crystallinity of over 80 percent after being roasted in the air at 600 DEG C for 3 hours or after undergoing hydrothermal treatment with vapor at 650 DEG C for 1 hour, as well as high thermostability and hydrothermal stability.

The present invention relates to the preparation of hyperstable Y-type RE molecular sieve for the catalytic cracking of heavy oil and containnig vanadium resisting component. The preparation uses NaY-type molecular sieve as main material and chemical aluminum-eliminating complex containing oxalic acid and/or oxalate and its mixture and through introducing RE ion in the late stage of chemical aluminum elimination reaction to from RE precipitate and hydrothermal treatment to realize hyperstabilizing and introduce RE ion and independent phase Re oxide. The formed precipitate RE precursor includes RE oxalate. Compared with conventional REY, REHY and REUSY, the molecular sieve preparing process is simple and high in RE utilization, and has homogeneously distributed aluminum, more secondary pores high hydrothermal stability, high activity and high vanadium contamination resisting capacity.

The invention discloses a hydrodewaxing catalyst and its preparation method. With the weight of the catalyst as the reference, the catalyst contains the following components of: by weight, 5-10% of tungsten oxide, 1-5% of nickel oxide, 40-50% of nanometer ZSM-5 molecular sieve, 10-40% of macroporous alumina and the balance being a binder. The catalyst is prepared by the following steps of: firstly kneading the nanometer ZSM-5 molecular sieve, macroporous alumina and the binder to prepare a carrier, dipping loaded active metal, and finally carrying out hydrothermal treatment. The hydrodewaxing catalyst provided by the invention has a good shape-selective catalysis function and simultaneously has a good hydrofinishing function, and is especially suitable for the hydrofinishing and pour point reduction processes of a waxy hydrocarbon oil material containing high content of impurities such as sulfur, nitrogen and the like.

The present invention discloses a method for preparing a wide aperture mesoporous silica molecular sieve fiber. An industrialized nonionics or cationic surfactant is adopted as a template. An organic or inorganic silicon source is adopted as a precursor. In the state where various auxiliary reagents, such as inorganic salt, alcohol and the like, are added, the fiber is synthesized through the cooperative assembly between a surface active agent and inorganic species and a hydrothermal treatment process. The mesoporous silica molecular sieve fiber is between 3 and 20 nm in aperture, between 0.3 and 2.5 cm^3/g in pore volume, and between 600 and 1200 cm^2/g in specific area. The material is easy to obtain, the technical requirements are comparatively simple, and the operation is feasible. The method has a very wide application range in terms of the preparation of composite fortifying fiber and semiconductor porous nanometer tube and nanometer wire in the fields of nanometer microelectrode and aviation material.

The invention discloses a method for preparing fewer-layer graphene on the basis of biomass waste, which comprises the following steps: carrying out hydrothermal treatment on the biomass waste, and carrying out carbonization by heating and calcination, thereby obtaining a carbonization material; immersing the carbonization material in an acid solution to remove impurities, thereby obtaining biomass carbon; and quickly heating the biomass carbon in an argon atmosphere, and carrying out high-temperature graphitization to obtain the biomass fewer-layer graphene. The hydrothermal process is combined with the high-temperature graphitization to directly strip the biomass waste, and the carbonization and high-temperature graphitization are carried out. Thus, the prepared biomass fewer-layer graphene has the advantages of fewer layers (2-10 layers), fewer defects, fewer oxy groups, high electric conductivity and small carbon layer interval. The method is simple to operate, has the advantages of low cost and high graphene yield, and can easily implement industrialized large-scale production. The prepared biomass fewer-layer graphene can be used in the fields of lithium ion batteries, supercapacitors and the like, is beneficial to green production of battery industry, and has important practical value and favorable application prospects.

The invention discloses a preparation method for a multi-hole carbon nitride photocatalytic material doped with sulphur, belonging to the technical field of synthesis of photocatalytic materials. The preparation method comprises the following steps of preparing a super-molecule polymer through simple hydro-thermal treatment by taking melamine and trithiocyanuric acid as a raw material and taking water as a solvent, and burning in an inert atmosphere so as to obtain a three-dimensional network sulphur-doped multi-hole carbon nitride photocatalytic material. The preparation method provided by the invention has the advantages that simplicity and easiness in preparation are achieved, a method for burning a super-molecule polymer is adopted, any template agent and a surface active agent do not need to be added, a reaction system is simplified, the cost is low, the pollution of a reagent is slight, the reaction repeatability is good, a preparation condition is mild, the time consumption of a synthetic process is short, and the requirement on equipment is high; the multi-hole carbon nitride photocatalytic material doped with sulphur has excellent catalytic activity in a catalyzing hydrogen production reaction, and the hydrogen production rate of the material is 8.3 times and 5.2times that of a product obtained by burning melamine and trithiocyanuric acid under the same condition.

The invention relates to linear alkanes dehydrogenation catalyst carrier technics used in petrochemical industry. Its aperture distribution can be adjusted through producing macroporous alumina globule. Then add surface active agent in globule dropping process. Finally conduct hydrothermal treatment in supporter producing process. On base of self-research, globule dropping technics is designed by self to make product cost reduce remarkably. Using self produced macroporous alumina dropping globule, side pressure intensity of alumina globule can reach more than 20N per grain. Using self-researched macroporous gamma-Al2O3 with binocular construction, reaction performance of linear alkanes dehydrogenation catalyst can reach conversion>12-13 percent and selectivity>90 percent. Compared with international like products, its stability is better.

The invention discloses a method for preparing a low-carbon olefin catalyst by high-activity-stability carrier-type iron-based synthetic gas. Silica gel is taken as a carrier, and a metal promoter and an active component Fe are loaded by adopting an immersion method, wherein the used silica gel carrier is firstly subjected to hydrothermal treatment, and the condition for the hydrothermal treatment is that 50%-100% water vapor is used for carrying out the hydrothermal treatment for 0.5-20h at the temperature of 150-600 DEG C. After the silica gel carrier used in the method disclosed by the invention is subjected to the hydrothermal treatment, the strong interaction between the carrier and the active component is overcome, and thus, the activity and the selectivity of the catalyst are improved. The catalyst prepared by the method disclosed by the invention is applicable to the reacting processes of preparing the low-carbon olefins, such as ethylene, propylene, butylene and the like, from the synthetic gas.

The invention discloses a preparation method of a mesoporous-microporous composite molecular sieve. The preparation method comprises the following steps of adding a microporous molecular sieve subjected to hydrothermal treatment into a mixed system of a silicon source, an acid solution and a surfactant, then carrying out crystallization, filtration and washing, and then carrying out drying and calcination to obtain the mesoporous-microporous composite molecular sieve. The preparation method fully utilizes non-framework aluminum falling from the microporous molecular sieve, avoids an aluminum source used by the conventional molecular sieve preparation technology, is conducive to improvement of a silica-alumina ratio of the mesoporous-microporous composite molecular sieve, realizes a high degree of crystallization, and improves hydrothermal stability and thermostability of the mesoporous-microporous composite molecular sieve. The mesoporous-microporous composite molecular sieve is suitable for the field of macromolecule catalysis, is conducive to improvement of a reaction conversion ratio and reaction selectivity, and is especially suitable for being used in a cracking catalyst for maximum-degree production of middle distillate from heavy oil as a raw material.

The invention discloses bismuth vanadate powder and a preparation method thereof. The method comprises the following steps: firstly, bismuth-bearing compounds and vanadium-bearing compounds are respectively dissolved in a nitric acid, mixed and then added with a hexadecyl trimethyl ammonium bromide solution, the mol ratio of bismuth to vanadium to the nitric acid to hexadecyl trimethyl ammonium bromide is 1 to 1 to 2.5 to 0.025, and the mixture is stirred for 1 to 2 hours by magnetic force so as to form a bismuth vanadate precursor; the bismuth vanadate precursor is placed in a reaction kettle, undergoes hydrothermal treatment for 70 to 75 hours at a temperature of between 80 and 200 DEG C, cooled, centrifugally separated, and then added with a saturated sodium chloride solution of anhydrous ethanol and deionized water; ion-exchange is performed after the bismuth vanadate precursor is completely immersed, and then centrifugal separation is performed; and finally the bismuth vanadate precursor is washed for 3 to 5 times by mixture of the deionized water and ethanol, then the bismuth vanadate powder with microspheric and/or micro-flaky particles is prepared. The method has simple operation and mild conditions; and bismuth vanadate powder particles prepared are uniform, have large specific surface area, have the characteristics of good visible light response and high photocatalytic activity, and are suitable for industrialized production.

The invention discloses a gahnitem, zinc oxide and nickel zinc nano-composite photocatalytic material which has a high specific surface area and a mesoporous structure and is prepared by roasting at high temperature by taking ternary hydrotalcite as a precursor. The material is used for the adsorption and the degradation of organic pollutants. The photocatalytic material is prepared by taking zinc nitrate, nickel nitrate, aluminum nitrate, sodium carbonate, sodium hydroxide and the like as raw materials; preparing the raw materials into salt solutions and alkali solutions respectively; mixing the solutions by using a constant-flow pump at the temperature of 80 DEGC with magnetic stirring, transferring the mixed solution into a hydrothermal reaction kettle; performing hydrothermal treatment at 130 to 180 DEG C; performing suction filtration, washing and drying to the precursor; roasting the precursor in Muffle furnace for 2 to 6 hours at the temperature of 400 to 600 DEG C to obtain the product, wherein the specific surface area is greater than 150 m<2>.g<-1>. The photocatalyst disclosed by the invention has regular shape, large specific surface area, and super-high capacity for adsorbing and degrading organics, and can be reused; the raw materials for preparing the composite photocatalyst are abundant, the cost is low, and the process is simple.

The invention discloses a method for preparing a multi-level porous titanium-silicon molecular sieve, which comprises the following steps: (1) After mixing the silicon source, the structure-directing agent, the titanium source and water uniformly in a certain proportion, directly adding a silylating agent or first After pre-crystallization, a silylating agent is added to obtain a reaction mixture containing a silylating agent; (2) the reaction mixture containing a silylating agent is crystallized under certain conditions in a pressure-resistant airtight container, and then recovered to obtain a crystallized product; (3) the recovered crystallized product is roasted and then treated with alkali to obtain an alkaline mixture; (4) the alkaline mixture is hydrothermally treated in a pressure-resistant airtight container, and the product is recovered. The hierarchically porous titanium-silicon molecular sieve obtained by the technical scheme has the advantages of high crystallinity, high macromolecular reactivity and selectivity, and adjustable pore structure.

The invention relates to a method for preparing a carbon nanoparticle/two-dimensional layered titanium carbide composite material. The method includes the steps that a two-dimensional layered titanium carbide nano material MXene (Ti3C2/Ti2C) is prepared through hydrofluoric acid corrosion; the material MXene (Ti3C2/Ti2C) and monosaccharide are processed through ultrasonic treatment, vacuum impregnation, hydrothermal treatment and other steps, so carbon nanoparticles are generated between layers and on the surface of the MXene (Ti3C2/Ti2C) material, and the carbon nanoparticle/two-dimensional layered titanium carbide composite material is obtained. Raw materials which are not toxic and easy to obtain are adopted, the preparation process is simple, the technology is controllable, cost is low, repeatability is good, the layered structure of the prepared two-dimensional layered MXene (Ti3C2/Ti2C) is uniform and complete, the carbon nanoparticles are evenly distributed between the layers and on the surface of the MXene (Ti3C2/Ti2C) material, and the prepared composite material has the advantages of being large in specific surface area, good in conductivity, good in hydrophilic property and the like and can be used in the fields such as functional ceramic, wave-absorbing materials, supercapacitors and ion batteries.

The invention relates to a method for preparing extrafine anatase titanium dioxide nano rods, which comprises that: (1) titanium containing inorganic substances are hydrolyzed, the temperature is raised to be between 20 and 100 DEG C, inorganic base solution is added for heat preservation and hydrolysis and neutralizes pH to between 7 and 8, and precipitation of hydrous titanium dioxide is obtained; (2) the precipitation is repeatedly washed, added with oxyful, stirred and subjected to ultrasonic dispersion, the temperature is raised to be between 0 and 50 DEG C and the heat is preserved for 1 to 24 hours; and (3) water solution of pertitanic acid is diluted by deionized water, then filled into a hydrothermal reaction kettle, subjected to hydrothermal treatment at a temperature between 100 and 250 DEG C for 2 to 48 hours, and cooled to room temperature. The preparation method is simple; the obtained sol does not contain organic stabilizer; and the titanium dioxide in the sol is anatase, has a rod-shaped structure and high length-diameter ratio, and can form extrafine rod-shaped nanocrystal titanium dioxide.

The invention discloses a preparation method of biomass pomelo peel derived activated carbon serving as an electrode material of a super capacitor. The preparation method comprises the following steps: a pomelo peel is subjected to hydrothermal treatment for mild carbonization firstly, a pomelo peel adopting a porous structure is obtained, a hydrothermal product of the pomelo peel and potassium hydroxide are mixed for soaking, so that potassium hydroxide sufficiently diffuses into the pomelo peel, a mixture is calcined at a high temperature finally, carbon balls are activated by potassium hydroxide, and a honeycomb activated carbon material adopting leveled hole structures is prepared. Honeycomb activated carbon prepared with the method has rich leveled hole structures and larger specific surface area, the electrode capacity is as high as 300 F/g when the activated carbon serves as the electrode material of the super capacitor, and the method has the characteristics of simplicity in process operation, high repeatability and low cost.

The invention relates to a synthesis method of nano-molybdenum carbide. The synthesis method comprises the following steps: dissolving a molybdenum precursor in hydrogen peroxide, dissolving carbohydrates in water, mixing the molybdenum precursor with the carbohydrates, stirring, loading a mixed solution into a hydrothermal kettle, and performing hydrothermal treatment to obtain a black product; cooling the black product, then washing and performing suction filtration on the product, drying, baking in a passivation gas atmosphere, replacing with passivation gas when the temperature is reduced to room temperature, and performing passivation treatment to obtain the nano-molybdenum carbide. The synthesis method provided by the invention has the advantages of simplicity, easiness in control, economical efficiency, reasonableness and large specific surface area with mesoporous structure.

The invention discloses a preparation method of a mesoporous SiOx/C composite negative material of a lithium-ion battery, and belongs to the fields of new materials and electrochemistry. The preparation method comprises the following steps of: taking polyvinylpyrrolidone as an auxiliary template agent, taking an organic surface active agent as a template agent and organic silicon as a silicon source, obtaining mesoporous silica precursor by hydrothermal treatment, adding a carbon source, and preparing SiOx/C composite negative material with a mesoporous structure by carbothermic reduction reaction occurring in the process of high-temperature thermal treatment. The preparation method disclosed by the invention has the advantages that the specific capacity of the material is high, the structure is novel, and simultaneously the cycling stability is good; the yield is high; and the prepared SiOx/C composite material is fine in particle, uniform in particle size and component distribution, high in specific capacity and good in cycling stability, is an ideal composite negative material of the lithium-ion battery, and can be widely applied in the fields such as various portable electronic equipment, electric vehicles and aerospace.

The invention discloses a preparation method of calcium sulfate hemihydrate crystal whiskers high in length diameter ratio. The method includes firstly subjecting soluble inorganic calcium salt and inorganic sulfate to coprecipitation at the temperature of 10-90 DEG C, activating for 1-6 hours at the temperature of 40-150 DEG C to obtain a precursor after filtering and washing, adding the precursor into a hydrothermal medium with crystal form control agent for hydrothermal treatment for 2-10 hours at the temperature of 80-180 DEG C, washing, filtering and drying hydrothermal products, and then obtaining calcium sulfate hemihydrate crystal whiskers in the diameter of 0.1-4 micrometers, the length of 20-3000 micrometers and the length diameter ratio of 50-1000, uniform in shape and identical in size. The preparation method is simple, mild in conditions and low in cost of materials which are easy to obtain, and is easy to industrially popularize. The main content of the calcium sulfate hemihydrate crystal whiskers prepared by the preparation method is larger than 98%, and the calcium sulfate hemihydrate crystal whiskers are uniform in shape and diameter and high in additional value and can be expectedly used as high-performance reinforcing materials for the industries of ceramics, plastics, rubber and paper making and the like.