31results about How to "Uniform mesoporous structure" patented technology

The invention discloses a preparation method of a composite functional fresh-keeping paper based material with enhanced slow release function. The preparation method comprises following steps: 1, beta-cyclodextrin and essential oil are weighed to prepare essential oil microcapsules; 2, the essential oil microcapsules and a mesoporous molecular sieve are mixed, water is added, and high speed oscillation treatment is carried out so as to obtain a molecular sieve loaded with the essential oil microcapsules; 4, the molecular sieve loaded with the essential oil microcapsules, a starch solution, a chitosan solution, and an inorganic salt solution are mixed and stirred at a ratio, deionized water is added to adjust the solid content to be 5 to 10% so as to obtain a coating solution; 5, the surface of food package body paper is uniformly coated with the coating solution; and 6, the coated paper is dried fully at room temperature so as to obtain the functional fresh-keeping paper based material. The fresh-keeping paper prepared using the above preparation method is capable of prolonging the storage period of packaged products, and the service life of the fresh-keeping paper can be prolongedat the same time.

The invention discloses a precious metal methanation catalyst prepared by using a solution combustion method, which comprises the following components in percentage by weight: 1-10% of precious metal oxides and 90-99% of a carrier. The precious metal methanation catalyst disclosed by the invention has the advantages that the catalyst is applicable to a trace CO methanation process, and stable in catalytic performance.

The invention discloses a method for preparing high-specific-surface-area porous carbon with hemp stems as a carbon source, and belongs to the field of nano-carbon material preparing. According to the method, the agricultural waste hemp stems serve as the carbon source, and the method aims at solving the problem that existing hemp stem active carbon is low in specific surface area. The method includes the following steps that 1, hemp stem cores are pretreated into powder, and the hemp stem core power is obtained; 2, the hemp stem core powder obtained in the step 1 is added into a compounded catalyst solution, stirred under the condition of 80-100 DEG C till water is evaporated to be dry and dried, and a compound precursor is obtained; 3, the compound precursor prepared in the step 2 is subjected to high-temperature carbonization heat treatment in the inert gas atmosphere environment; 4, then acid cleaning is carried out, a product is centrifugally separated, then washed with water to be neutral and dried, and the porous carbon is obtained. The method has the advantages that cost is low, the technology is simple, and the high-specific-surface-area porous carbon can be prepared; the high-specific-surface-area porous carbon is used as a hydrogen storage material, a catalyst carrier, an electrode material and the like.

The invention discloses a method for preparing a carbon material with uniform pore sizes by a block polymer as a template. The method comprises 1) mixing an aqueous block polymer solution and an aqueous graphene oxide dispersion to obtain a polymer-mixed graphene oxide dispersion, 2) hydrothermally treating the dispersion for a reaction to obtain template-doped reduced graphene oxide aerogel, 3) dehydrating and drying the reduced graphene oxide aerogel under vacuum conditions to obtain graphene composite gel, 4) freeze-drying the reduced graphene oxide aerogel to obtain loose porous graphene aerogel, 5) tabletting the graphene aerogel to obtain graphene sheets and 6) carrying out heat treatment on the graphene composite gel and the graphene sheets to obtain a carbon material. The method has good controllability of the pore sizes. The carbon material can be processed into an all-solid-state electrode. The cylindrical carbon can be used as an adsorbent material.

The invention discloses a ZnO/In2O3 heterogeneous II type photocatalytic material with a hollow core-shell structure and a preparation method thereof. The preparation method comprises the following steps: step 1, dissolving zinc salt and indium salt into a mixed solution of water, ethylene glycol and polyethylene glycol; 2, adding urea and sodium citrate into the solution obtained in the step 1 while stirring to obtain a reaction system mixed solution; 3, transferring the reaction system mixed solution obtained in the step 2 to a high-pressure reaction kettle for hydrothermal reaction; and 4,cooling the hydrothermal reaction product obtained in the step 3 to the room temperature, performing centrifuging, washing, drying and calcining to obtain the ZnO/In2O3 heterogeneous II type photocatalytic material with the hollow core-shell structure. According to the method, the hollow shell-core structure and the heterogeneous II-type photocatalytic material are constructed at the same time through a simple one-step hydrothermal method, and the nanoparticles prepared through the method are small in particle size and can effectively inhibit in-vivo recombination of carriers, so that the photocatalytic efficiency is improved.

The invention discloses a defective metal organic framework photocatalyst and a preparation method thereof. The defective type metal organic framework photocatalyst is a defective MIL-53 metal organicframework photocatalyst. The preparation method comprises the following steps: with ferric trichloride hexahydrate and terephthalic acid as raw materials and N,N-dimethylformamide as a solvent, carrying out solvothermal reaction under the action of an acid regulator to prepare the defective metal organic framework photocatalyst. The photocatalyst has the advantages of being uniform in mesoporousstructure, high in specific surface area, wide in light absorption range, small in forbidden band width, large in photocurrent, small in impedance, high in photocatalytic activity and the like. The catalyst is a novel visible-light photocatalyst, which is novel in morphology and structure and excellent in photocatalytic performance, and has very good use value and application value. The preparation method has the advantages of simple process, convenience in operation, low cost and the like, is suitable for large-scale preparation and is beneficial to industrial application.

The invention discloses a preparation method of a cellulose-polyvinyl alcohol composite film based on phase inversion and a preparation method of a supercapacitor. The preparation method comprises thefollowing steps: preparing a cellulose solution from sodium hydroxide, urea and cellulose raw materials; mixing the cellulose solution and a polyvinyl alcohol solution in proportion to form a film toobtain a thin film, wherein cellulose in the thin film accounts for 10-25% of the solid content of the thin film; soaking and regenerating the film by using a mixed solution of calcium chloride and hydrochloric acid, then soaking and plasticizing the film by using glycerol, and finally drying to obtain the cellulose-polyvinyl alcohol composite film. The cellulose and -polyvinyl alcohol compositefilm is prepared by taking cellulose as a raw material and sodium hydroxide, urea and water as solvents and adopting a dissolution-regeneration and phase inversion method. Compared with a traditionalpolyolefin material, the composite film has the advantages of good tensile strength, elongation at break and lyophilicity and high porosity, liquid absorption rate and liquid retention rate. The supercapacitor assembled by the composite film can show good electrochemical performance.

The invention discloses a medium/low temperature mesoporous nitrogen oxide and dioxin removal catalyst and a preparation method thereof. According to the catalyst, a mesoporous carbon-silicon composite material is adopted as a carrier, and one or more of vanadium pentoxide, tungsten oxide, cerium oxide and manganese oxide are adopted as active components. The catalyst disclosed by the invention iscapable of effectively achieving synergetic removal of NOx and dioxin within a medium/low temperature range of 180-300 DEG C, and in addition, the catalyst disclosed by the invention has the advantages of being large in specific surface area, ordered in pore height, small in active metal particle size and uniform in active metal particle size distribution.

The invention provides a catalyst for catalytic oxidation of VOCs and a preparation method of the catalyst. The active component of the catalyst comprises a composite oxide of copper and manganese, and a carrier is not needed. The preparation method comprises the following steps: (1) preparing a precursor: dissolving a copper salt and a manganese salt in a mixed solution of ethanol and ethylene glycol to obtain a solution A, dissolving oxalic acid in another ethanol and ethylene glycol solution to obtain a solution B, pouring the solution B into the violently stirred solution A at room temperature, reacting the solution for 0.5-2 hours at room temperature, separating generated sol-gel, and drying the sol-gel at 60-120 DEG C to obtain a solid; (2) heat treatment: calcining the solid obtained in the step (1) at 250-450 DEG C for 1-3 hours to obtain the catalyst. The catalyst has the characteristics of easy preparation, low cost, high activity and the like, and can completely degrade toluene; meanwhile, the synthesis period is short, the production cost is low, no harmful gas such as NOx is generated in the reaction process; the method has the advantages of being economical in raw material, convenient to operate, controllable in reaction condition, capable of reducing environmental pollution, capable of working continuously and the like.

The invention discloses a tourmaline TiO2 composite material preparation method, and belongs to the field of composite materials. The tourmaline TiO2 composite material preparation method comprises: mixing and uniformly stirring titanium tetraisopropanolate and ethanol according to a volume ratio of (3-4):10; uniformly dispersing tourmaline powder in a mixing solution comprising ethanol and water according to a volume ratio of 2:1 so as to make the mass fraction of the tourmaline is 5-9%; carrying out ultrasonic dispersion for 1 h with ultrasonic waves with a power of 100 W; mixing the tourmaline/ethanol/water solution and the titanium tetraisopropanolate/ethanol solution, and continuously stirring the sol mixture until generating a brown gel; transferring the brown gel mixture into a reaction kettle, carrying out a solvothermal reaction for 24 h at a temperature of 120 DEG C, and drying the wet gel after completing the reaction to obtain a dry gel, wherein the heating rate is 1 DEG C/min; and carrying out a heat treatment on the dry gel for 24 h at a temperature of 100 DEG C, and washing three times with distilled water at a room temperature to obtain the tourmaline TiO2 composite material. The prepared TiO2 composite photocatalyst of the present invention has advantages of low cost and no pollution, and can directly use solar energy to perform degradation.

The invention discloses a self-nitrogen-doped palladium-loaded porous composite structure oxygen reduction catalyst, and a preparation method and an application thereof. The preparation method comprises the following steps: preparing a spinning solution from polyvinylpyrrolidone, polyacrylonitrile, an organic solvent, graphene oxide and palladium salt, carrying out electrostatic spinning, and sequentially carrying out pre-oxidation, carbonization and reduction treatment on an obtained precursor to obtain the self-nitrogen-doped palladium-loaded porous composite structure oxygen reduction catalyst which has the characteristics of a large specific surface area, rich mesoporous structures, uniform morphology and the like. The catalyst is used as a cathode oxygen reduction catalyst for a proton exchange membrane fuel cell, has the characteristics of high catalytic activity, high stability under an alkaline condition and the like, and is simple in preparation process and low in cost, a pore forming agent and a nitrogen doping reagent do not need to be additionally added in the preparation process, the process steps are simplified and production cost is reduced.