16 results about "Oxidation-reduction process" patented technology

The invention belongs to the technical field of solar cell materials, and particularly relates to silver-coated copper powder and a preparation method thereof. A preparation method of silver-coated copper powder comprises the following steps that copper powder subjected to surface activation through an acid-base solution and a complexing agent are dissolved in water, and copper powder turbid liquid is obtained; dropwise adding a silver source solution into the copper powder turbid liquid to carry out a replacement reaction, and adjusting the pH value of the solution after the reaction to obtain a silver-coated copper powder precursor turbid liquid; and dropwise adding a reducing agent solution into the silver-coated copper powder precursor turbid liquid, then dropwise adding a silver source solution, carrying out oxidation-reduction reaction, carrying out solid-liquid separation, washing, and drying to obtain the silver-coated copper powder. According to the preparation method provided by the invention, in the chemical oxidation reduction process, the silver-coated copper powder with different silver layer distribution structures, compact silver coating structure and better performance is obtained by regulating and controlling the dropping sequence and dropping rate of the reducing agent solution and the silver source solution.

The invention discloses preparation of a monatomic graphene type photo-thermal catalyst and application of the monatomic graphene type photo-thermal catalyst in catalyzing aldose to produce ketose, and the preparation comprises the following steps: loading a monatomic precursor (X) on a graphene type carbon material (GT) by adopting a solution impregnation method, further reducing the monatomic precursor into a corresponding monatomic (Y) by adopting a continuous oxidation-reduction method, the monatomic graphene type photo-thermal catalyst is obtained, and the monatomic graphene type photo-thermal catalyst is expressed as Ysg / GT. The catalyst is used for catalyzing other different aldoses (maltose, glyceraldehyde, erythritol and xylose) to produce corresponding ketose, the catalyst shows good catalytic activity and photo-thermal performance, and the ketose yield is larger than 50%. Finally, in the reusability research of the catalyst, the catalyst is found to have good activity and structural stability, the chemical equilibrium limit of the reversible reaction is broken through, the reaction rate is increased, and the catalyst can help to develop an efficient and green catalyst to open up a new way for the reversible reaction process.

The application provides a preparation method of gold powder for matching low-temperature co-fired ceramic, and submicron irregular gold powder is prepared in an aqueous solution of chloroauric acid through an oxidation-reduction method. In the preparation process, amino acid is used as a gold ion complexing agent and a pH buffer of a reaction solution, a small-molecule organic substance containing an imidazole functional group and having weak reduction is used as a reducing agent, and after the gold powder is washed with deionized water, ethanol is used to replace water in the powder, and the like, so that submicron irregular gold powder which is not agglomerated is prepared. The gold powder prepared by the application has a particle size range of 200nm-900nm, has good dispersibility in alcohol and ester solvents, and after sintering, a film layer is dense, can be matched with various green ceramic materials at home and abroad, and after sintering, a substrate is flat and has a warping degree less than 0.1mm. The preparation method of the application has high yield and is convenient in the preparation process.

The application discloses a kind of synthesis methods of high-purity electronic grade sodium hypophosphite, dilute phosphine gas is passed into to the mixed solution of sodium hypochlorite and sodium hydroxide that has been pre-cooled with sufficient stirring, and sodium hydroxide is added to carry out reaction;After reaction is completed, filtration, concentration, crystallization, separation are carried out, and the obtained product is purified by resin to obtain high-purity electronic grade sodium hypophosphite product.Compared with the traditional "yellow phosphorus-lime-soda" oxidation-reduction method for preparing industrial grade product and then preparing high-purity electronic grade sodium hypophosphite, the product purification difficulty of the application is low, by using 7N grade ultra-high purity phosphine without any metal impurities, the problem that arsenic, silicon, germanium, nickel, chromium and other metal impurities cannot be completely removed by traditional process can be effectively solved.In addition, the application also has the advantages of effectively solving the problem of three wastes, high recycling rate of by-products, high economy and the like.

The invention discloses a method for preparing schizophyllum commune polysaccharide through high-pressure homogenization and application of the schizophyllum commune polysaccharide, and belongs to the technical field of food and medical treatment. On the basis of a traditional water extraction and alcohol precipitation process, the molecular weight and viscosity of schizophyllum commune fermentation liquor polysaccharide are remarkably reduced through a high-pressure homogenization technology, the schizophyllum commune fermentation liquor polysaccharide is smoother in morphology, and meanwhile a triple-helix structure is maintained; the physical properties of the polysaccharide treated by the method are optimized, and the immunoregulation, anti-apoptosis and anti-oxidative damage activity are also remarkably enhanced. Furthermore, the polysaccharide-selenium nanoparticle compound is prepared from the polysaccharide, sodium selenite and L-ascorbic acid through a mild one-step oxidation-reduction method, the water solubility, biocompatibility and bioavailability of the polysaccharide can be effectively improved through the compound, and the polysaccharide-selenium nanoparticle compound shows more excellent apoptosis resistance and oxidation resistance in a model experiment.

The invention discloses a preparation method of a Co porphyrin / graphene interlayer confinement catalyst, and belongs to the field of preparation of organic nano materials. The method comprises the following steps: firstly synthesizing free porphyrin (such as HTPP) through metallization reaction, and then reacting with cobalt salt to insert cobalt ions to synthesize Co porphyrin. The layered graphene is synthesized by using an efficient and mild oxidation-reduction method. And finally, limiting Co porphyrin molecules between graphene layers by utilizing pi-pi accumulation and electrostatic interaction to form the domain-limited catalyst with a layered structure. The preparation method has the characteristics that a good layered structure can promote reactant enrichment and directional conversion of an intermediate, the stability of a Co active center is enhanced by utilizing a confinement effect, an electron transmission path (from graphene to Co porphyrin) is optimized, the catalytic activity of the catalyst is improved, and the application potential is relatively large.

The invention discloses a hydrogel wound dressing as well as a preparation method and application thereof. The preparation method disclosed by the invention is used for preparing the hydrogel from an oil tea fruit shell extracting solution and fruit shell residues through a double-auto-oxidation-reduction method. The preparation method comprises the following steps: (1) extracting oil tea fruit shells; (2) preparing an acetic anhydride esterification product of the camellia oleifera shell residues; (3) preparing green nano-silver particles; (4) preparation of catechin-loaded microspheres; and (5) preparing the hydrogel wound dressing. The hydrogel wound dressing prepared by the invention has good mechanical strength, self-healing property, sterilization and anti-inflammation effects and the like, and the wound healing speed can be increased.

The invention provides a preparation method of a calcination-free low-temperature denitration catalyst and the catalyst, and belongs to the technical field of preparation of denitration catalysts.The method comprises the steps that a strong oxidant is added into a mixed salt solution for a hydrothermal reaction, and an active component oxide is obtained; the preparation method comprises the following steps: adding montmorillonite into deionized water, adding an organic modifier in a stirring state, and carrying out a hydrothermal reaction to obtain organic montmorillonite; the active component oxide and the organic montmorillonite are subjected to ball milling, tabletting and screening, and the calcination-free low-temperature denitration catalyst is obtained. According to the preparation method, montmorillonite modified by an organic modifier is taken as a carrier, an active component oxide is prepared by using an oxidation-reduction method, and the active component oxide is loaded on the carrier by using a ball milling method, so that the obtained MMnTiOx / OMt catalyst can be used for NH3-SCR (Selective Catalytic Reduction) denitration treatment of low-temperature flue gas after dust removal-desulfurization, and the conversion rate of NOx is greater than 95% and the selectivity of N2 is greater than 90% within 100-180 DEG C.

The application discloses a kind of redox processes for realizing the efficient recovery of chromium complex in Cr (III) -EDTA-containing wastewater, first, appropriate sodium percarbonate, formic acid is added to Cr (III) -EDTA-containing wastewater containing heavy metal chromium, and stirring is dissolved;Immediately, ozone is introduced into the mixed solution, and the oxidation of active species hydroxyl radical and carbonate radical, the reduction of active species carbon dioxide radical is generated by ozone / sodium percarbonate / formic acid advanced oxidation reduction method, which realizes the rapid complex breaking of chromium complex in wastewater, the reduction of hexavalent chromium, and the rapid removal of chromium ions in wastewater;At the same time, the organic ligand EDTA in wastewater is rapidly mineralized and decomposed under the oxidation of highly active free radicals.The application can realize the efficient complex breaking of chromium complex in Cr (III) -EDTA-containing wastewater and the synchronous removal of heavy metal chromium, and the heavy metal chromium is recycled, which has the advantages of economic efficiency, simple operation, easy engineering application, etc.

The invention provides a Cu2O / Cu modified strontium titanate photocatalytic material and a preparation method thereof. A Cu2O / Cu / SrTiO3 ternary p-n heterojunction is successfully constructed through an oxidation-reduction method and an impregnation method. Energy band matching of p-type Cu2O and n-type SrTiO3 is utilized to promote photo-induced electrons to be transferred from a SrTiO3 conduction band to a Cu2O conduction band, holes are reversely migrated, and charge recombination is effectively inhibited; the surface plasma resonance (SPR) effect of the nano Cu particles expands visible light absorption to 600 nm, and the nano Cu particles serve as electron transmission channels to accelerate carrier migration. The material has a liquid-phase formaldehyde removal rate of 91.6% under visible light, which is 6.5 times of that of pure SrTiO3 and 2.4 times of that of Cu2O / Cu, the formaldehyde purification rate still exceeds 85% after circulation for 4 times, a green and environment-friendly redox-impregnation method is adopted in the preparation process, no toxic reagent is needed, the raw material cost is low, the preparation process is green and simple, and the material has efficient and stable photocatalytic performance.

The invention discloses a reaction furnace capable of observing the change of a reaction column for element isotope analysis, which is mainly used for visualization and quantification of an oxidation-reduction process in an element-stable isotope ratio mass spectrometer and comprises a reaction furnace body, a reaction tube and an observation strip, the reaction tube is arranged in the reaction furnace body, an opening is formed in the surface of the reaction tube, a through hole is formed in the surface of the reaction furnace body, the observation strip is arranged between the through hole and the opening, the observation strip covers the through hole and the opening in a sealing manner, and the observation strip is made of a transparent material. By adopting the arrangement, the oxidation reduction process can be observed and quantified at any time during use, and the visualization and quantification of the ash content volume and the reduced copper residual degree are realized.

The application discloses a method for rapidly preparing a high-sensitivity three-dimensional circular hole aerogel stress sensor and belongs to the technical field of porous carbon materials. The method comprises the following steps: (1) graphite powder is subjected to an oxidation-reduction method to obtain graphene oxide (GO) with a large specific surface area and good dispersibility; and MAX is etched by hydrochloric acid to obtain a carbon titanium carbide (MXene) suspension with excellent conductive performance; (2) GO, MXene, ascorbic acid and a foaming agent are mixed and then subjected to a hydrothermal reaction to obtain a composite hydrogel; (3) the composite hydrogel is subjected to freezing, freezing and thawing in ethanol and then air drying, and is subjected to carbonization by a Joule heating device to obtain a composite carbon aerogel with good mechanical properties; and (4) the composite aerogel is attached to a graphite foil electrode to assemble a stress sensor. The method is simple and has the potential of rapidly preparing a high-sensitivity aerogel stress sensor; the prepared aerogel has high compressibility and super-high sensitivity, and is expected to be used as a matching device for modern intelligent equipment.

The invention provides a preparation method of an ultra-fine grain ODS-Cu composite material for synergistically improving mechanical-electrical conductivity, and relates to the technical field of copper-based composite materials and preparation. The method comprises the following steps: preparing superfine ODS-Cu powder containing 0.5-1.5 wt% of Al2O3 by adopting an in-situ endogenous oxidation-reduction method, carrying out cold isostatic pressing, sintering under a hydrogen protection atmosphere, carrying out hot extrusion and annealing to obtain a densified ODS-Cu formed blank, and drawing or rolling to obtain an intermediate plate; carrying out low-temperature annealing on the intermediate plate and then transferring the intermediate plate into liquid nitrogen until the core temperature of the plate is less than or equal to-150 DEG C; and the obtained plate is subjected to multi-pass cold rolling treatment, and the composite material is obtained. Compared with similar copper-based dispersion strengthening or severe plastic deformation routes in the prior art, the tensile strength and the yield strength can be improved by more than 10%, the ductility can be improved by more than 50%, the electric conductivity is higher than 75% IACS, and the softening temperature is higher than 900 DEG C.

The invention provides a ferroelectric-polyacid coupled long-memory composite electrochromic film as well as a preparation method and application thereof, and belongs to the technical field of electrochromic materials and devices. The thin film is composed of FTO conductive glass, a TiO2 porous framework layer, a P2W17V polyacid layer deposited in the framework and a P (VDF-TrFE) ferroelectric functional layer, and a built-in electric field generated by polarization of the ferroelectric layer is deeply coupled with a polyacid oxidation reduction process, so that charges are effectively locked, ion diffusion is inhibited, and the limitation of traditional physical lamination is broken. The optical memory time of the prepared film is prolonged from 489.8 s to 2357.2 s, the bistable performance is remarkably enhanced, and the technological process is simple.

The invention relates to a method for electrodeposition of cobalt in a cobaltous sulfate system and application, the method comprises the following steps: S1, preparing an electrolyte containing cobaltous sulfate, and depositing a cobaltosic oxide film on the surface of a working electrode by adopting a cyclic voltammetry method; s2, stripping the cobaltosic oxide film from the working electrode and drying to obtain cobaltosic oxide powder; and S3, the cobaltosic oxide powder is subjected to ball milling at the temperature of 200-300 DEG C, and a cobaltosic oxide finished product is obtained. The deposition process is regulated and controlled through a cyclic voltammetry oxidation-reduction method, cobaltosic oxide is prepared through electro-deposition in a cobaltous sulfate system, lattice defects and the specific surface area of cobaltosic oxide are precisely regulated and controlled, and efficient deposition of cobaltosic oxide is achieved.

The invention discloses a preparation method for controlling the number of layers of graphene, belongs to the technical field of graphene preparation and application, and solves the problems of low yield and high energy consumption and equipment cost in the existing method for controlling the number of layers of graphene. The invention discloses a preparation method for controlling the number of layers of graphene. The preparation method comprises the following steps: S1, pretreating a graphite raw material by adopting an airflow mill to obtain a high-activity raw material; s2, performing microwave and ultrasonic treatment on the high-activity raw material; and S3, carrying out surface modification on the material obtained in the step S2 by adopting a plasma process to obtain graphene. The defect density of the graphene prepared by the method is lower than that of the graphene prepared by a traditional oxidation-reduction method, the conductivity and tensile strength of the graphene prepared by the method are superior to those of the graphene prepared by the traditional oxidation-reduction method, and the method is low in energy consumption, low in cost and more suitable for large-scale preparation.