39results about How to "Inhibition of hydrogen evolution side reaction" patented technology

The invention discloses a carbon nanofiber/metal composite electrode for a flow battery and a preparation method thereof. The electrode material is prepared by the following steps of: taking a mixtureof a high-molecular polymer and a metal salt as a precursor; preparing nanofibers by adopting an electrostatic spinning method; and performing high-temperature carbonization treatment, and performingsurface oxidation and etching to manufacture the electrode material, wherein the diameter of the carbon nanofibers is 100-1000 nm, the diameter of the metal particles is 2-100 nm, the metal particlesare distributed on the surfaces of the carbon nanofibers, one parts of the metal particles are embedded into the carbon nanofibers, and the other parts of the metal particles are exposed out of the surfaces of the carbon nanofibers. The carbon nanofiber/metal composite electrode prepared by adopting the preparation method has good electrocatalytic activity and electrochemical reversibility when used for the flow battery, and has the advantages of simple preparation method, few procedures, easily available raw materials, low price and the like.

The invention discloses a photoelectrocatalytic system and a method for recovering precious metal silver while degrading organic pollutants. The photoelectrocatalytic system comprises a photoelectric reactor, a photo-anode, a cathode, electrolyte and a persulfate solution, wherein the photoelectric reactor is used for containing the electrolyte and the persulfate solution; the photo-anode and the cathode are arranged in the photoelectric reactor; the photo-anode is connected with the cathode by means of an external circuit; the photo-anode is a visible light responsive photocatalytically active semiconductor photoelectrode. The invention also discloses the method for recovering precious metal silver while degrading organic pollutants; wastewater containing silver ions and the organic pollutants is added into the photoelectrocatalytic system, and a photoelectrocatalytic reaction is carried out under the action of visible light. The method provided by the invention can realize efficient removal of the organic pollutants and the recovery of the precious metal silver, the removal rate of the organic pollutants can reach 96.5% or above, and the total recovery rate of the silver ions can reach 94.6% or above.

The invention provides an aqueous electrolyte and an aqueous metal ion battery. The aqueous electrolyte provided by the invention comprises a stabilizer, a metal salt and water, wherein the stabilizeris an oxygen-containing non-alcohol organic solvent of C3-C6; the oxygen-containing non-alcohol organic solvent of C3-C6 is selected from acetone and/or triethyl phosphate; and the metal salt is selected from one or more of lithium salt and sodium salt. The aqueous electrolyte is formed by matching the specific stabilizer with water and metal salt, so that high-potential water can be effectivelyinhibited from being oxidized into oxygen to cause an oxygen evolution side reaction, and low-potential water can be effectively inhibited from being oxidized into hydrogen to cause a hydrogen evolution side reaction, and the electrochemical stability window of the aqueous electrolyte is further improved; and the formed aqueous electrolyte has a stable electrode/electrolyte interface, high conductive effect, and relatively high capacity retention rate and coulombic efficiency.

The invention relates to the technical field of through hole processing of HDI (high density inverter) printed wiring boards and particularly relates to a high-uniformity electroplating device for through holes of an HDI (high density inverter) printed wiring board. The device comprises an electroplating bath (1), an anode (2), a cathode (3) and a rectifying power supply (5), wherein the electroplating bath (1) is internally provided with a spraying mechanism (4) which can move in the electroplating bath (1) to directionally spray the surfaces of the through holes of the HDI board at a high speed. The cathode deposition currents on the surfaces of the through holes of the HDI board obtained are uniformly distributed, the copper layers are continuously distributed and are uniform in thickness, compact in organization structure, and good in conductivity, and the plating quality is improved. By using the electroplating device, the cathode current efficiency in the electroplating device is high, the hydrogen evolution side reaction is better inhibited, the efficiency of the electroplating production process is improved and the influence of hydrogen evolution on the quality of the copper layers is reduced, thereby facilitating reduction of the production cost.

The invention relates to an electrode for CO2 electrochemical reduction and preparation and application of the electrode for CO2 electrochemical reduction. The preparation process of the electrode includes the steps of soaking a substrate material into an electroplating liquid containing main salt and additives after performing impurity removal on the substrate material, and performing electrochemical deposition under inert atmosphere protection and stirring conditions to obtain the electrode with micrometer Cu particles growing on the surface. The proportion of side atoms of the Cu particlesdeposited on the substrate surface of the prepared electrode is much higher than that of corner atoms, which is beneficial to improving the coverage of CO* on the surface of the electrode and providesa favorable environment for a subsequent CO* dimerization reaction and a hydrogenation reaction; and the electrode has a significant effect of inhibiting the side reaction of hydrogen evolution and meanwhile has high C2H4 selectivity.

The invention relates to application of a metal ion additive which is stable in an alkaline solution and has high hydrogen evolution overpotential in a zinc-nickel flow battery, which belongs to the field of flow batteries. The additive is one or more of divalent soluble lead salt and divalent soluble tin salt. The additive is stable in property in an alkaline solution and has high hydrogen evolution overpotential, and the deposition potential is higher than that of zinc ions. In the battery charging process, the negative electrode generates a small amount of hydrogen evolution side reaction,battery performance is influenced, after the additive is added, in the initial stage of charging, divalent lead ions and divalent tin ions in a solution can preferentially obtain electrons to become elemental lead to be deposited on a negative electrode, hydrogen evolution side reaction during zinc deposition is inhibited due to high hydrogen evolution overpotential of the elemental lead and the elemental tin, and when the two ions are introduced together, the effect is optimal, so that the coulombic efficiency of the battery is improved by the method.

The invention relates to a polypyrrole/nano-copper composite gas diffusion electrode and preparation and an application thereof. Carbon paper or carbon cloth serves as a substrate, a polypyrrole layer with the thickness being 0.05-1.0 [mu]m is attached to the surface of the substrate, and a nano-copper material layer with the thickness being 0.1-1.0 [mu]m is deposited on the polypyrrole layer. Polypyrrole is aggregated and nano-copper is deposited on the carbon-based electrode, the hydrogen evolution side reaction is reduced, and the Faradic efficiency of products is improved and the conversion rate of carbon dioxide is increased.

The invention relates to a production method for a modified vanadium battery porous electrode graphite felt, which comprises the following steps: a pre-oxidized felt sequentially enters a low-temperature carbonization zone and a high-temperature graphitization zone of a continuous sintering furnace to be sintered, and then enters a continuous activation furnace to be activated; before the graphitefelt is subjected to activating treatment, a catalyst bismuth nitrate powder is uniformly scattered on the surface of the graphite felt, so that one-catalyst and two-step modification effect can be realized. That is, the added bismuth nitrate not only can oxidize the surface of the felt body to form a nanoscale microporous structure and increase the specific surface area, but also the bismuth nitrate can be decomposed in the activation process, and the decomposed product is deposited on the surface of the carbon felt to further modify the surface of the carbon felt. The production method hasthe advantages that the electrochemical reaction activity can be improved, the side reaction of the electrode can be inhibited, and the service life of the battery is prolonged. The cost is saved in industrial production, and the method is simple, easy to operate and high in environmental protection property.

The invention provides a method for preparing metal rhodium or rhodium alloy by electrodeposition or chemical deposition. The method comprises an electrodeposition method and a chemical deposition method, adopts a weakly acidic plating solution or a basic plating solution and comprises the following steps for preparing metal rhodium or rhodium alloy: (1) preparing a complex solution of rhodium according to composition and method described in the patent CN105906668B; (2) preparing a complex solution of dissimilar metal ions; (3) preparing a mixed solution containing a reducing agent and an additive; (4) proportionally mixing the solutions obtained in steps (1), (2) and (3) and regulating pH with ammonium hydroxide and an acid solution; (5) preparing a rhodium or rhodium alloy clad layer with the electrodeposition method or the chemical deposition method. A weakly acidic or basic solution system is adopted in the method, a replacement reaction in a strongly acid plating solution is avoided, binding force of the clad layer is good, the problems of low current efficiency and high porosity caused by massive hydrogen evolution of the strongly acid system are solved, and by means of adoption of an improved complexing agent and introduction of the additive, stability of the basic plating solution is improved.

The invention relates to a method for preparing 1,3-butadiene by electrocatalytic acetylene coupling, and a gas diffusion electrode electrolytic tank is adopted. A gas diffusion electrode is adopted,a catalyst is sprayed on a gas diffusion layer substrate (including conductive carbon paper and metal) to prepare the gas diffusion electrode, and a cathode and an anode are isolated by an ion exchange membrane. A three-electrode or two-electrode system constant-voltage method is adopted to carry out electrochemical performance test, wherein the reaction gas is high-purity acetylene. Experimentalresults show that the Faraday efficiency of the target product 1,3-butadiene reaches 70% or more by regulating and controlling a proper voltage range, and byproducts ethylene and hydrogen are easy toseparate from 1,3-butadiene. Compared with a traditional thermocatalysis technology, the method has the advantages that the production cost of 1,3-butadiene can be effectively reduced, the huge pressure brought by the coal-rich lean oil energy resource structure in China is relieved, the technical requirements of green chemical engineering are met, and the method has great strategic significance.

The invention discloses a method for preparing a glass fiber separator for a lead carbon battery with double functions of in-situ pore enhancement and negative electrode hydrogen evolution suppression. The method comprises the following steps of: first preparing glass fiber separator slurry; then adding an additive with double functions of in-situ pore enhancement and negative electrode hydrogen evolution suppression thereto; using dilute sulphuric acid to dilute and adjust a pH value of the slurry; filtering and molding the slurry to obtain a semi-finished product of the glass fiber separator; and drying, trimming, slicing the semi-finished product or the like to prepare the glass fiber separator for the lead carbon battery with double functions of in-situ pore enhancement and negative electrode hydrogen evolution suppression. According to the method for preparing the glass fiber separator for the lead carbon battery, particles of the additive that are acid-soluble and have the doublefunctions of in-situ pore enhancement and negative electrode hydrogen evolution suppression are added and evenly distributed on the glass fiber separator. The glass fiber separator is used between positive and negative electrodes of the lead carbon battery. When acid is added during manufacturing of the lead carbon battery, the double-function micro-scale additive particles in the separator are dissolved and released ions. The released ions are directionally adsorbed, electroreduced, and deposited on a surface of a carbon material during a charging process. Therefore, the negative electrode hydrogen evolution overpotential is improved, the side reaction of the hydrogen evolution is suppressed, and the self-discharge during storage of the battery is reduced.

The invention relates to a preparation technology of an electrochemical oxidation electrode material, and aims at providing a method for preparing a Ti/SnO2-Sb (titanium/tin dioxide-antimony) electrode by a tricarboxylic organic acid-Sn(II)/Sb(III) complex. The method comprises the following steps of using the pretreated Ti sheet as a working electrode, arranging counter electrodes at both sides in parallel, and respectively soaking the working electrode and the counter electrodes into an electrodeposition solution, wherein the electrodeposition solution is a mixed water solution of stannous dichloride, antimony trichloride, tricarboxylic organic acid and gelatin; connecting a positive pole of a direct current power source and the counter electrodes, and connecting a negative pole and theworking electrode; after the electrodeposition is completed, drying the working electrode at room temperature without cleaning; after drying, warming for 1 to 3h at the temperature of 450 to 650 DEG C, and cooling to room temperature, so as to obtain the electrode product. The preparation technology has the advantages that the operation is simple, the environment-friendly effect is realized, and the cost is low; the electrode surface is uniform and complete, and the covering degree is good; the antimony-doped tin dioxide is uniformly and densely distributed at the electrode surface, the specific surface area is high, and more active sites are provided in the electrochemical oxidation process; the service life of accelerated test of the electrode product is long, and the stability is good.

The invention provides a recyclable charge-modified mesoporous nanocellulose paper-based zinc ion battery diaphragm, which is prepared by the following steps: treating nanocellulose by adopting a simple process, weighing a certain mass of seaweed nanocellulose powder, putting the seaweed nanocellulose powder into water, performing ultrasonic dispersion to obtain a uniform cellulose suspension, performing suction filtration, and drying to obtain the charge-modified mesoporous nanocellulose paper-based zinc ion battery diaphragm. The original cellulose diaphragm is obtained; the seaweed nanocellulose diaphragm has a very small pore size, different substances are used for charge modification on the basis, and compared with a negative charge diaphragm, the obtained positive charge diaphragm is more favorable for improving the cycle performance of the battery; the preparation process is simple, the material source is rich, no pollution is caused to the environment, the battery performance can be greatly improved, compared with an existing common diaphragm, the diaphragm is lighter and thinner and has better mechanical strength, and more space and capacity are reserved for a positive electrode and a negative electrode; according to the invention, the unique effect of the surface charge in the aqueous battery is explored, and the stability and the rate characteristic of the zinc ion battery are greatly improved.

The invention relates to a method for preparing glycolic acid by electrocatalytic reduction of CO2 in a heteropolyacid ionic liquid indium dual-catalytic system. The invention belongs to the field ofpreparation of glycolic acid by electrocatalytic reduction of CO2. The invention aims to solve the technical problems that the existing CO2 reduction reaction is generally 2e-, 4e- transfer reaction,the deep reduction of CO2 cannot be realized, and the ionic liquid preparation process of the existing reaction system is complex. The method comprises the following steps: preparing polyoxometallateionic liquid (n-Bu4N) 3SVW11O40, dissolving the polyoxometallate ionic liquid (n-Bu4N) 3SVW11O40 in acetonitrile to obtain a catholyte, and carrying out electrocatalytic reduction on carbon dioxide byusing dilute sulfuric acid as an anolyte to prepare liquid-phase products ethanol and acetic acid which are greater than or equal to C1. The method provided by the invention is simple, effectively solves the problems that the existing polyacid ionic liquid is rare in variety and short in quantity, is mild in reaction condition and low in economic cost, and can improve the energy efficiency to 4-5times, and the Faraday efficiency of the obtained ethanol is 7-16%, and the Faraday efficiency of the obtained acetic acid is 14-67%.

The invention discloses a metal zinc negative electrode protected by a chemical passivation layer. The chemical passivation layer is generated on the surface of the zinc metal negative electrode in situ through a chemical passivation method. The active component of the passivation solution used in the chemical passivation method is one or more of vanadate, silicate and titanate, and the solvent is water. The invention further discloses a corresponding preparation method. Therefore, the inventor also develops a corresponding aqueous zinc ion battery, and the passivation layer is uniformly distributed, so that water and oxygen can be effectively isolated, the aqueous zinc ion battery has an anti-corrosion characteristic, and hydrogen evolution side reaction of a zinc negative electrode in charge-discharge circulation is inhibited; meanwhile, the zinc negative electrode can induce uniform deposition of zinc and inhibit growth of dendritic crystals, the cycle performance of the zinc negative electrode is remarkably improved, and the cycle stability of the zinc negative electrode is improved. In short, the zinc metal negative electrode is simple in production process and low in raw material cost, and the obtained battery product is good in effect and suitable for large-scale production.

The invention is applied to the field of zinc-iron flow batteries, and particularly relates to a negative electrode electrolyte for a zinc-iron flow battery. An electrolyte in a negative electrode electrolyte of the zinc-iron flow battery comprises a zinc salt, an additive and a supporting electrolyte, the zinc salt is one or two of zinc chloride, zinc bromide, zinc sulfate and zinc iodide, the additive is nicotinamide, and the supporting electrolyte is potassium ions or sodium ions. According to the invention, by selecting the additive and utilizing the complexing structure of divalent zinc ions and the additive and the adsorption effect of a zinc deposition layer and the additive, the growth of zinc dendrites and the generation of byproducts are inhibited, the zinc deposition morphology is improved, the zinc deposition is compact and uniform, the performance of the battery is improved, and the cycle life of the battery is prolonged. The invention has the advantages of outstanding performance, safety, environmental protection, low price and the like.

The invention belongs to the field of photocatalytic CO2 reduction, and particularly relates to a construction method and application of a Pickering microbubble system for preparing methanol through photocatalytic reduction of CO2. The Pickering microbubble system is a CO2-in-water microbubble system, which is formed by taking an amphiphilic Pickering solid photocatalyst as an emulsifying agent and spontaneously assembling the amphiphilic Pickering solid photocatalyst on a gas-water interface. When the system is used for photocatalytic CO2 reduction reaction, the reduction efficiency can be improved by 10-80% in comparison with that of the traditional gas-liquid two-phase reaction, and the selectivity of the reduction product methanol can be improved by 20-80%.