160 results about "Potassium cyanide" patented technology

The invention provides a gold leaching agent for treating high-carbon gold-bearing minerals and a gold leaching process, and belongs to the technical field of hydrometallurgy. According to the gold leaching agent, guanidinium thiocyanate is used as an agent main body, a hydroximic acid compound is used as a complexing synergist, and soluble inorganic salt of ferric iron is used as a competitive adsorbent. In a leaching system, guanidine thiocyanate can be decomposed to generate guanidine, sodium sulfide, sodium thiocyanate and water. Thiourea anions are converted into cyanamide under the alkaline condition, then cyanamide is slowly released and decomposed into cyanide ions, the cyanide ions are complexed with gold ions, and gold leaching is achieved. Namely, guanidinium thiocyanate has the effect of releasing the cyanide ions step by step, and slow release of the cyanide ions is realized. The gold leaching agent system does not contain cyanide (sodium cyanide, potassium cyanide and the like) and is a clean and environment-friendly agent system, and efficient leaching of gold in high-carbon gold-bearing minerals can be achieved through the synergistic effect of all functional agent components.

The invention discloses a Prussian blue analogue electrode and a preparation method and application thereof.The preparation method comprises the following steps that a manganese salt solution, a nickel salt solution and a potassium ferricyanide solution are prepared and added into water at the same time, a mixture with the molar ratio of manganese to nickel being larger than or equal to 0.1: 1 is obtained, aging, washing and drying are conducted, and the Prussian blue analogue electrode is obtained. And mixing the manganese-doped Prussian blue analogue with a binder, a conductive agent and a solvent, carrying out ultrasonic treatment to obtain an electrode slurry liquid, covering the surface of a current collector with the electrode slurry liquid, and drying to obtain the Prussian blue analogue electrode. The Prussian blue analogue electrode prepared by the method has the advantages of low energy consumption, high salt adsorption capacity, high salt adsorption rate and the like, can be used for desalting treatment as a capacitive deionization cathode, has the salt adsorption rate and the salt adsorption capacity which are more than two times of those of a conventional electrode, and is high in use value, good in application prospect and wide in application prospect. The method is of great significance in promoting wide application of the capacitive deionization technology.

The invention belongs to the technical field of electrochromic materials, and provides a red-transparent display electrochromic polymer and a preparation method thereof. The method disclosed by the invention comprises the following steps: carrying out ring formation reaction on N-(2, 5-dibromophenyl)-2-ethylhexyl thioamide, potassium ferricyanide and sodium hydroxide to obtain 4, 7-dibromo-2-(heptane-3-yl) benzothiazole; the preparation method comprises the following steps: carrying out substitution reaction on EDOT, n-butyllithium and tributyltin chloride to obtain EDOT-Sn; the preparation method comprises the following steps: carrying out Stille coupling reaction on 2, 4, 7-dibromo-2-(heptane-3-yl) benzothiazole and EDOT-Sn, and then carrying out electrochemical polymerization reaction to obtain the electrochromic polymer. A pure donor (D) type organic molecule is obtained by the method, a corresponding electrochromic film is prepared by electrochemical polymerization, reversible switching between red and transparency is realized, and the electrochromic film has good cycle stability and high color change response speed.

The invention discloses a preparation method and application of a catalytic membrane based on monatomic iron-manganese oxide, and belongs to the field of catalytic membrane water treatment. The invention aims to solve the problems that a chromium fog inhibitor F-53B in the existing chromium plating wastewater is difficult to degrade, and the degradation rate is greatly reduced when residual PAM and F-53B coexist. The method comprises the following steps: 1, preparing a casting solution; 2, dripping the membrane casting solution into pores of a hollow ceramic membrane substrate and drying; 3, preparing a potassium ferricyanide aqueous phase solution; 4, preparing a manganese acetylacetonate oil phase solution; and 5, dipping the dispensed ceramic membrane substrate in a potassium ferricyanide water-phase solution, dropwise adding a manganese acetylacetonate oil-phase solution into pores of the ceramic membrane substrate subjected to water-phase treatment, and finally calcining. The application comprises the following steps: degrading chlorinated polyfluoroalkyl ether sulfonate; or in the presence of polyacrylamide, the catalyst is used for degrading the chlorinated polyfluoroalkyl ether sulfonate. The preparation method is used for preparation and application of the catalytic membrane based on the monatomic iron-manganese oxide.

The invention discloses a high-crystallinity carbon nitride nanosheet based on a heterogeneous fused salt interface as well as a preparation method and application thereof, and belongs to the technical field of photocatalysis. The preparation method comprises the following steps: carrying out hydrothermal reaction on a melamine solution or a melamine mixed solution to obtain a supramolecular precursor; mixing the supramolecular precursor with heterogeneous molten salt, and calcining in a protective atmosphere to obtain the high-crystallinity carbon nitride nanosheet; the heterogeneous molten salt is a mixture of potassium thiocyanate and potassium chloride. The heterogeneous fused salt interface is used as a reaction environment, ideal interface driving force is provided for directional assembly of a precursor and formation of a high-crystallization carbon nitride nanosheet, then preparation of a carbon nitride photocatalytic material with a controllable structure and excellent performance is achieved, and an illumination reaction is carried out in an air environment to catalyze production of hydrogen peroxide.

The invention relates to the technical field of non-metallic material preparation, solar energy utilization and green energy production, in particular to a carbon nitride dark photocatalyst as well as a preparation method and application thereof. The preparation method of the carbon nitride dark photocatalyst comprises the following steps: calcining melamine I to obtain common carbon nitride; grinding and uniformly mixing the common carbon nitride and potassium thiocyanate to obtain a precursor mixture; calcining the precursor mixture II to obtain a carbon nitride dark photocatalyst precursor; and adding the carbon nitride dark photocatalyst precursor into water for soaking and stirring, then carrying out solid-liquid separation, and sequentially washing and drying the obtained solid to obtain the carbon nitride dark photocatalyst. The carbon nitride dark photocatalyst can produce hydrogen peroxide in the dark. The limitation that a traditional photocatalyst cannot react under the dark condition is solved, and the photocatalyst can be used as an efficient hydrogen peroxide production catalyst to be applied to clean energy production and has a good application prospect.

The invention discloses a catalyst Cr, Co-Ni (OH) 2 (at) NF based on a nickel base. The catalyst is prepared by taking foamed nickel (NF) as a carrier and doping Cr and Co elements, has efficient urea oxidation reaction (UOR) performance, and can be used for hydrogen production by electrolysis of water and urea pollution treatment. The preparation method comprises the following steps: soaking nickel foam in an HCl solution, soaking the nickel foam in a nickel salt solution with a specific concentration for reaction to generate nickel-based hydroxide, and soaking the nickel-based hydroxide in a solution containing chromic nitrate and cobalt potassium cyanide for reaction to finally generate the catalyst doped with Cr and Co. The catalyst shows low overpotential and good stability in a 1M KOH + 0.33 M urea solution, the overpotential of an anode for hydrogen production through electrolysis of water is remarkably reduced, and meanwhile efficient degradation of urea is achieved.

The invention provides a method for rapidly synthesizing thiocyano-substituted formanilide, which belongs to the technical field of organic chemical preparation, and comprises the following steps: taking alpha-aminoketone and potassium thiocyanate as initial raw materials, sealing in an oil bath pan under the condition of a copper catalyst, an oxidizing agent and an organic solvent, stirring at 80 DEG C, and heating to react for 24 hours, thereby obtaining the thiocyano-substituted formanilide. The copper catalyst comprises any one of copper chloride, copper acetate, copper sulfate, copper acetylacetonate and copper trifluoromethanesulfonate, and the oxidizing agent comprises one of iodobenzene diacetic acid, potassium persulfate, di-tert-butyl peroxide and tert-butyl hydroperoxide. The method overcomes the problems of many reaction steps, low synthesis efficiency and the like in the prior art, and has the advantages of easily available raw materials, simple operation and the like.

The invention discloses an octadecahedral cerium-cobalt composite oxide lithium battery negative electrode material and a preparation method thereof, and the preparation method comprises the following steps: dissolving cerium salt in absolute ethyl alcohol to prepare a cerium salt alcoholic solution; the preparation method comprises the following steps: dissolving cobalt potassium cyanide in water to prepare a cobalt salt solution, and sequentially adding glucose and sodium carboxymethyl cellulose to obtain a mixed aqueous solution containing glucose, sodium carboxymethyl cellulose and cobalt salt; mixing the two solutions, stirring to obtain white precipitate, centrifugally separating, washing with ethanol for three times, and drying to obtain a white cerium-cobalt precursor; and placing the obtained cerium-cobalt precursor in a crucible with a cover, wrapping the cerium-cobalt precursor with a thin foil, carrying out high-temperature calcination in a muffle furnace, and naturally cooling to obtain the octadecahedral cerium-cobalt composite oxide. The octadecahedral cerium-cobalt composite oxide negative electrode material disclosed by the invention has a special microstructure, relatively good charge-discharge capacity and good cyclicity.

This invention discloses a method for recycling and reusing cyanide silver plating wastewater. The method includes four steps: separation of silver ions and cyanide, concentration of the silver-containing solution, cyanide concentration, electrolysis and residual liquid recycling, and reuse of reclaimed water. This method achieves the separate recycling and reuse of silver, cyanide, and water. The silver-containing solution is electrolyzed to obtain metallic silver, the cyanide concentrate's main component is sodium cyanide or potassium cyanide solution, and the reclaimed water with a conductivity below 20 μS / cm is reused in the production line. This method not only maximizes resource utilization and reduces wastewater discharge, but also separates most of the cyanide from the silver-containing solution during electrolysis, making the electrolysis process safer. Furthermore, the residual liquid after electrolysis can be recycled multiple times for the separation and concentration of silver ions and cyanide.

The invention relates to the technical field of sodium ion battery negative electrode materials, and discloses a preparation method and application of a copper-iron sulfide nitrogen-doped porous carbon composite material, and the preparation method comprises the following steps: (1) mixing copper salt, potassium ferricyanide, a nitrogen source and polyethylene glycol, and carrying out ball milling to obtain a copper-iron Prussian blue precursor; (2) pyrolyzing the copper-iron Prussian blue precursor in an inert atmosphere, washing to remove impurities, and drying to obtain an intermediate product; and (3) carrying out heat treatment on the intermediate product and a sulfur source in an inert atmosphere to obtain the copper-iron sulfide / nitrogen-doped porous carbon composite material. Through the synergistic effect of compounding of the bimetallic sulfide and the nitrogen-doped porous carbon, sodium ions with larger ion radiuses are more easily embedded and deembedded in interlayer spacing, and meanwhile, abundant active sites are provided to enhance the storage of the ions, so that the lithium ion battery has outstanding rate capability and stable cycle performance.

The invention relates to the technical field of oxygen free radical detection, in particular to a manufacturing process of a portable and reliable oxygen free radical detector. Comprising the following steps: mixing superoxide dismutase, potassium ferricyanide, an isothiazolinone preservative, hexammine ruthenium chloride, polyethylene glycol octylphenol ether, trehalose and bovine serum albumin, and uniformly stirring to prepare an enzyme preparation; mixing an enzyme preparation with the high polymer material solution to form reagent layer slurry with viscosity; uniformly coating the reagent layer slurry on a substrate material, and drying; printing an electrode material on the substrate material to form a working electrode and a counter electrode; the silver electrode is placed in an electrolyte containing chloride ions, potential is applied, the silver surface is subjected to a chlorination reaction, and a silver / silver chloride electrode is formed; covering the reagent layer above the electrode, tightly combining the reagent layer with the electrode in a sticking or hot pressing manner, and cutting to obtain the test paper; the prepared portable oxygen free radical detector can be used for conveniently and efficiently detecting oxygen free radicals of a human body at low cost.

The invention discloses a preparation method of a potassium-doped nitrogen oxidation phosphorescent catalyst, and belongs to the technical field of photocatalytic material preparation. The method comprises the following steps: by taking phosphorus oxynitride and potassium thiocyanate as raw materials, grinding and mixing, carrying out molten salt reaction at 400-600 DEG C for 1-5 hours, and cooling, washing and drying a reaction product to obtain the potassium-doped phosphorus oxynitride crystal. The method is simple in process, mild in reaction condition, low in cost and easy for large-scale production. Through potassium element doping, the visible light absorption range of phosphorus oxynitride is effectively widened, the recombination rate of photo-induced electron-hole pairs is remarkably reduced, and the carrier separation and transmission efficiency is improved, so that the photocatalytic activity of the material is greatly improved. The prepared K-PON photocatalyst has wide application prospects in the fields of photocatalytic reduction of uranium-containing wastewater, degradation of organic pollutants, energy conversion and the like.

The invention relates to a preparation method of a layered magnesium-based flame-retardant smoke-suppression hybrid material, which comprises the following steps: (1) dispersing organic anion intercalated magnesium-based LDHs into a Tris-HCl buffer solution with the pH value of about 8.5 to obtain slurry A; then adding bio-based polyphenol into the slurry A, continuously stirring, and carrying out suction filtration, washing and freeze drying to obtain organic anion intercalation magnesium-based LDHs coated with polyphenol on the surface; (2) dispersing the organic anion intercalation magnesium-based LDHs coated with polyphenol on the surface into deionized water, then adding soluble cobalt salt, soluble nickel salt and sodium citrate, and continuously stirring to obtain slurry B; and (3) adding a transition metal potassium cyanide solution into the slurry B under continuous stirring, then aging, and carrying out suction filtration, washing and freeze drying to obtain the layered magnesium-based flame-retardant and smoke-suppression hybrid material. The method is simple, low in cost and easy to implement, and the obtained material solves the problems that an anchored transition metal compound is large in particle size, uneven in distribution, lack of synergistic effect and the like.

The application relates to the technical field of sodium ion battery negative electrode materials, and discloses a preparation method and application of a copper-iron sulfide / nitrogen-doped porous carbon composite material, which comprises the following steps: (1) mixing copper salt, potassium ferricyanide, a nitrogen source and polyethylene glycol, and obtaining a copper-iron Prussian blue precursor after ball milling; (2) pyrolyzing the copper-iron Prussian blue precursor under an inert atmosphere, washing and removing impurities, and drying to obtain an intermediate product; and (3) heat-treating the intermediate product and a sulfur source under an inert atmosphere to obtain a copper-iron sulfide / nitrogen-doped porous carbon composite material. Through the synergistic effect of the double-metal sulfide and the nitrogen-doped porous carbon composite, sodium ions with a larger ion radius can be more easily embedded and de-embedded in the interlayer spacing, meanwhile, abundant active sites are provided to enhance ion storage, so that the sodium ion battery has outstanding rate performance and stable cycle performance.

The invention relates to the technical field of sodium ion battery negative electrode materials, and discloses a preparation method and application of a multi-confinement iron-tin Prussian blue derivative sulfide carbon composite material, and the preparation method comprises the following steps: (1) adding a tin salt and a surfactant into a mixed solution of water, absolute ethyl alcohol and hydrochloric acid to prepare a solution A; (2) adding a potassium ferricyanide aqueous solution into the solution A, stirring, transferring into a reaction kettle, and carrying out solvothermal reaction to obtain an iron-tin prussian blue analogue; (3) dissolving the iron-tin Prussian blue analogue and a high-molecular polymer in N, N-dimethylformamide to form a spinning solution; and then carrying out electrostatic spinning, pre-oxidation, carbonization and sulfuration treatment in sequence to obtain the iron-tin Prussian blue derivative sulfide carbon composite material. According to the invention, the iron-tin Prussian blue analogue is encapsulated in the one-dimensional porous carbon nanofiber to form a spatial confinement, so that the volume change and stress of the active material in the charge-discharge process are effectively relieved, and the overall electrochemical performance is improved.

The invention provides a Prussian blue analogue derivative Ce-doped Co-based catalyst and a preparation method thereof.The preparation method comprises the steps that cerium salt and cobalt salt are dissolved and mixed to prepare a mixed solution, cobalt potassium cyanide solution is prepared, the cobalt potassium cyanide solution is dropwise added into the mixed solution, and the Prussian blue analogue derivative Ce-doped Co-based catalyst is obtained after the cobalt potassium cyanide solution is dropwise added into the mixed solution; the Ce-doped Co-based catalyst is prepared by dropwise adding a mixed solution or a cobalt cyanide potassium solution, adding polyvinylpyrrolidone into the mixed solution or the cobalt cyanide potassium solution before dropwise adding to further regulate and control the reaction rate, carrying out stirring reaction and aging to obtain a metal organic framework precursor with an irregular morphology, and finally calcining to obtain the Ce-doped Co-based catalyst. Based on earlier-stage scientific achievements, when cobalt salt is additionally added to regulate and control the proportion of Ce and Co elements, it is accidentally found that when other cobalt salt and cerium salt coexist, Co-Co coordinated Ce-doped irregular-morphology Prussian blue analogues can be formed, and under the specific Ce and Co element proportion condition, the Prussian blue analogues can be used for preparing the Prussian blue analogues with the Co-Co coordinated Ce-doped irregular-morphology Prussian blue analogues with the Co-Co coordinated Ce-doped irregular-morphology Prussian blue analogues. And after being calcined, the catalyst has obviously higher ammonia decomposition conversion rate under a relatively low-temperature condition.

The invention discloses a bimetallic catalyst and a method for preparing polyether polyol by using the bimetallic catalyst, and relates to the technical field of polyether polyol preparation.The method comprises the steps that an ethylenediaminetetraacetic acid-crown ether covalent ligand is taken and added into absolute ethyl alcohol, a cobalt potassium cyanide solution is slowly and dropwise added, the mixture is stirred to be uniform, then a manganese-cobalt bimetallic catalyst precursor is slowly and dropwise added, stirring and centrifuging are conducted, and a precursor solution is obtained; and washing and drying in vacuum to obtain the manganese-cobalt bimetallic catalyst. Taking a manganese-cobalt bimetallic catalyst, adding the manganese-cobalt bimetallic catalyst into absolute ethyl alcohol, then adding the zinc-nitrogen co-doped charcoal, and carrying out ultrasonic treatment; stirring, centrifuging, alkali washing and vacuum drying are performed to obtain the bimetallic catalyst. The preparation method comprises the following steps: enabling propylene oxide to pass through a molecular sieve, uniformly mixing a bimetallic catalyst, 1, 4-butanediol and polyglycerol, and carrying out gas replacement; and adding epoxypropane, adding epoxypropane in batches when the pressure in the kettle is reduced to half of the initial pressure, and removing impurities to obtain the polyether polyol.

The invention discloses an aluminum-doped Prussian blue nano-enzyme, which has high peroxidase-like activity, and a preparation method of the aluminum-doped Prussian blue nano-enzyme comprises the following steps: 1) uniformly stirring and mixing polyvinylpyrrolidone, aluminum nitrate, potassium ferricyanide and hydrochloric acid to obtain a mixed solution; and 2) heating the mixed solution to react, centrifuging, washing with ultrapure water, and drying to obtain the Al-doped Prussian blue nano-enzyme with high peroxidase-like activity. The invention further discloses a glutathione content detection method constructed based on the aluminum-doped Prussian blue nano-enzyme, and the method is used for carrying out simple colorimetry or constructing a paper-based intelligent equipment sensing platform and is used for immediate detection of glutathione. The method disclosed by the invention is simple and rapid to operate and low in cost, and a new detection method is provided for instant detection of glutathione in a complex sample.

The present invention discloses a cyanase mutant, nucleic acid, recombinant expression vector and their applications, belonging to the field of bioengineering. The cyanase gene derived from Escherichia coli E. coli K-12 substr. MG1655 was subjected to site-directed mutagenesis, so that the encoded amino acid sequence was mutated from glycine G to alanine A at the 37th position, from lysine K to arginine R at the 154th position, and from glutamine Q to histidine H at the 51st position. The specific activity of the cyanase mutant G37A / K154R / Q51H of the present invention against potassium cyanate is 2.4 times that before mutation, and the half-lives at 30 °C and 40 °C are increased by 2.1 times and 2.6 times respectively. The cyanase parent of the present invention cannot catalyze potassium cyanide, while the specific activity of the mutant G37A / K154R / Q51H against potassium cyanide reaches 5.5 U / mg, and the half-lives at 30 °C and 40 °C are 2.5 h and 3.0 h respectively. The cyanase mutant of the present invention can efficiently catalyze the decomposition of the substrates potassium cyanate and potassium cyanide, so as to achieve the purpose of degrading cyanide-containing wastewater, and can be widely applied to industries such as chemical engineering, pharmaceuticals and metallurgy, and has broad application prospects.

The invention discloses a preparation method of a cubic sulfide composite positive electrode material for a sodium-magnesium hybrid battery, which comprises the following steps of: 1, preparing a solution A from a cobalt source, preparing a solution B from cobalt potassium cyanide and a complexing agent, stirring the solution A and the solution B, standing, aging, washing and drying to obtain Co-PBA; 2, adding Co-PBA into a tris (hydroxymethyl) aminomethane buffer solution, adding a surfactant, carrying out ultrasonic treatment, adding dopamine hydrochloride, stirring, washing and drying to obtain a Co-PBA (at) PDA composite material; and 3, grinding the Co-PBA (at) PDA composite material, carrying out in-situ carbonization sintering, mixing with sulfur powder, and carrying out secondary sintering. The constructed polydopamine-coated Prussian blue analogue with the cubic structure is subjected to in-situ carbonization and vulcanization, the obtained CoS2 composite positive electrode material is uniform in particle size, stable in structure and excellent in electronic conductivity, the electrochemical performance including reversible capacity, cycling stability and rate capability is improved, and the CoS2 composite positive electrode material is suitable for a sodium-magnesium hybrid battery.

The invention belongs to the technical field of transition metal coordination chemistry, and relates to an easy-surface magnetic anisotropy cobalt single-ion magnet and a preparation method and application thereof, and the simple structural formula of the cobalt single-ion magnet is Co (bim) 4 (SCN) 2. The preparation method comprises the following steps: dissolving anhydrous cobalt chloride in absolute ethyl alcohol, adding potassium thiocyanate, stirring for 30 minutes, adding bim, fully reacting, and filtering to obtain a bluish violet solution; and placing the solution in a diethyl ether atmosphere, and standing for several days to obtain the cobalt single-ion magnet with easy surface magnetic anisotropy. The preparation method is safe and simple in preparation process, high in controllability, good in repeatability and high in yield. The prepared cobalt single-ion magnet is good in stability and high in purity, shows a slow magnetic relaxation behavior under an external magnetic field, and can be applied to the fields of novel high-density information storage equipment and the like as a molecule-based magnetic material.

The invention provides a method for rapidly synthesizing thiocyanate-substituted formanilide, belonging to the technical field of organic chemical preparation. Alpha-aminoketone and potassium thiocyanate are used as starting raw materials. Under the conditions of a copper catalyst, an oxidant and an organic solvent, the mixture is sealed and placed in an oil bath pot, stirred at 80°C, and heated for reaction for 24 hours. After the reaction is completed, the mixture is purified by column chromatography to obtain a thiocyanate-substituted formanilide compound. The copper catalyst comprises any one of copper chloride, copper acetate, copper sulfate, copper acetylacetonate and copper trifluoromethanesulfonate. The oxidant comprises one of iodophenyldiacetic acid, potassium persulfate, di-tert-butyl peroxide and tert-butyl peroxide. The method overcomes the problems of many reaction steps and low synthesis efficiency in the prior art and has the advantages of easy availability of raw materials, simple operation and the like.

The invention relates to the field of compound preparation, and discloses a method for preparing alkali metal ferrocyanide by using iron powder as an iron source through a mechanochemical method, and the method comprises the following steps: mixing the iron powder with a solution containing alkali metal cyanide to obtain a mixture, and enabling the water content of the mixture to be not more than 50wt%, the alkali metal cyanide comprises sodium cyanide or potassium cyanide, the reaction time is short, the reaction temperature is low, the process of treating the raw materials in advance is omitted, hydrolysis of the sodium cyanide is reduced, side reactions are reduced, a small amount of NH3 is released in the complexing reaction process, and the method is suitable for industrial production. The yield is high, sulfate containing ferrocyanide is not produced as a byproduct, and unreacted metal residues are recycled. Compared with a traditional method, the method disclosed by the invention is low in production cost and high in added value of products, and has a relatively good industrial prospect.

There are provided a silver-plated product having a more excellent wear resistance than that of conventional silver-plated products, and a method for producing the same. The method comprises the steps of: preparing a silver-plating solution which is an aqueous solution containing silver potassium cyanide or silver cyanide, potassium cyanide or sodium cyanide, and a benzothiazole or a derivative thereof; and forming a surface layer of silver on a base material by electroplating at a liquid temperature and at a current density in the silver-plating solution so as to satisfy (BC / A)2 / D≥10 (° C.2·dm2 / A) assuming that a concentration of free cyanide in the silver-plating solution is A (g / L), that a concentration of a benzothiazole content of the benzothiazole or derivative thereof in the silver-plating solution is B (g / L), that the liquid temperature of the silver-plating solution is C (° C.) and that the current density during the electroplating is D (A / dm2).

The present application relates to oxygen precipitation and oxygen reduction electrocatalyst technical field, especially an accordion type carbon supported single atom-cluster catalyst and preparation method and application. The present application first synthesizes a kind of accordion type coordination polymer containing zinc and iron series metal (such as iron, cobalt, nickel), then it is etched using potassium ferricyanide or potassium cobalticyanide;Finally, pyrolysis is carried out under nitrogen atmosphere, forming an accordion type carbon supported single atom-cluster catalyst. The new catalyst has a unique accordion type layered structure, higher specific surface area, more active sites, and the main skeleton nitrogen-doped carbon of the catalyst has good conductivity, which can accelerate the mass transfer and charge transfer process of electrocatalytic reaction. The present application belongs to a new type of bifunctional catalyst, which can catalyze oxygen reduction reaction and drive oxygen precipitation reaction, meet the needs of rechargeable zinc-air battery, and show potential application prospect to replace commercialized noble metal catalyst.

The invention discloses a medium-entropy nickel-based metal organic framework nano-array electrode and a preparation method and application thereof, and relates to the technical field of electrodes, the medium-entropy nickel-based metal organic framework nano-array electrode comprises a conductive net-shaped substrate and a medium-entropy nickel-based metal organic framework nanosheet loaded on the conductive net-shaped substrate, the medium-entropy nickel-based metal organic framework nanosheet is loaded on the conductive net-shaped substrate, and the medium-entropy nickel-based metal organic framework nanosheet is loaded on the medium-entropy nickel-based metal organic framework nano-array electrode. The medium-entropy nickel-based metal organic framework nanosheet is composed of a ligand prepared from nickel potassium cyanide and metal nodes, wherein the metal nodes are prepared from Ni < 2 + > and two or three metal ions selected from Co < 2 + >, Fe < 3 + > and Cr < 3 + >; the preparation method of the electrode is simple and efficient, the used raw materials are metal soluble salt and nickel potassium cyanide, and compared with a noble metal-based catalyst in industrial application, the electrode is low in cost, can be directly used as a self-supporting electrode for electrocatalytic urea oxidation reaction and is excellent in performance.

The invention belongs to the field of synthesis of drug intermediates, and particularly provides a preparation method of 1-benzyl-4-amino-4-piperidinecarboxylic acid, which comprises the following steps: 1, synthesizing a compound II by taking a compound I as an initial raw material, ammonium chloride, ammonia water and trimethylsilyl cyanide in the presence of a solvent; and 2, preparing a compound III from the compound II in the presence of acid. The route avoids the use of highly toxic substances such as sodium cyanide and potassium cyanide, is safer and more environment-friendly, is simple in product purification, high in yield and low in cost, and is very suitable for industrial production.

The invention relates to the technical field of production of potassium aurous cyanide, and discloses a thermal crystallization process of high-purity potassium aurous cyanide, which comprises the following steps: selecting a gold raw material, rolling to form a gold sheet, and pretreating the gold sheet; adding the pretreated gold platelets into electrolysis equipment, and carrying out electrolysis at preset voltage and current values by taking a potassium cyanide solution as anolyte; after the electrolysis operation is finished, heating and concentrating the filtered anolyte, and removing redundant water to obtain primary crystals; adding pure water, heating to dissolve the primary crystals again, acquiring dissolved state data of the primary crystals, and obtaining a dissolved state value based on the dissolved state data of the primary crystals; the solution with the dissolution state value meeting the requirement is placed in a freezer or a refrigerator to be frozen and drained to remove moisture, then drying is carried out, the high-purity potassium aurous cyanide thermal crystals are obtained, and recognition of the washing quality in the washing process is effectively completed through treatment of the dissolution state value.