47results about How to "Increase the limiting current density" patented technology

The invention provides a single-chamber microbial fuel cell, which takes a gas diffusion electrode as the negative electrode. The invention comprises a container, a positive electrode and a negative electrode; wherein, the positive electrode adopts a foamed metal electrode, the negative electrode adopts a gas diffusion electrode containing metallic catalyst, such as Ag, the container adopts a cylindric glass container, a water inlet opening is arranged at the lower end of the container, a water outlet opening is arranged at the upper end, a sealing cover is arranged at the upper part of the container, a sampling opening is arranged at the middle part of the sealing cover, the positive electrode is positioned at the inner side of the container, the negative electrode is positioned at the outer side of the container, the positive electrode and the negative electrode are arranged along the circumference of the container, copper conductors are connected between the both electrodes, and the both electrodes are connected with a load to form a closed loop. The gas diffusion electrode adopted by the invention exposes in the air, the oxygen gas in the air can be directly utilized as electron acceptors, an extra aerating device is not required; therefore the running cost is reduced. Organism, such as dextrose and discharge water can be used as the fuel of the cell, chemical energy can be effectively converted into electric energy; simultaneously, better discharge water processing effect can be achieved.

The invention discloses a sealed electrolysis bath and an electrolytic system, the electrolysis bath comprises two end plates, an anode component, a cathode component, sealing components and a compacting device, wherein liquid flowing ports are evenly arranged on the two end plates, liquid flowing through-holes are correspondingly arranged on the anode component and the cathode component, the anode component and the cathode component are separately arranged between the two end plates, a polar chamber is formed between the anode component and the cathode component, the sealing components are evenly arranged on the contact position of the anode component, the cathode component and the end plates, and the anode component, the cathode component and the end plates form a sealed structure after being compacted through the compacting device. The electrolysis bath has simple structure and can increase the circulation speed of electrolyte, the overpotential is effectively lowered, the current density of an anode and a cathode is increased when in electrolysis, the productivity of unit electrolysis bath is increased, and the electrolysis bath can be widely applied in electrowinning various metal and in electrowinning metallic solution with low concentration. The sealed structure avoids the influence of gas which is discharged in the electrolysis process to environment in a workshop.

The invention relates to a Fe-N doping porous carbon oxygen reduction catalyst. The Fe-N doping porous carbon oxygen reduction catalyst is prepared by the following steps: after uniformly mixing iron ions and silk fibroin solution, freeze-drying, and performing the high-temperature carbonization treatment to a freeze-dried product. The green and environmental silkworm cocoon in the natural world with the cheap price which is easily and extensively obtained is used as a precursor for successfully synthesizing the high-efficient Fe-N doping porous carbon catalyst for oxygen reduction. Through the optimization of a preparation technology, the suitable reaction conditions can be determined. The prepared catalyst has many advantages, such as the larger electric current density, the higher electron transfer number, the lower hydrogen peroxide yield, the good stability and methyl alcohol poison resistance.

The invention discloses a method for preparing a mono-/multi-valent ion exchange membrane by membrane fouling and electrodialysis deposition. The method utilizes a phenomenon that an electrolyte in asolution performs fouling on an ion exchange membrane, and employs an electrodialysis process to foul the surface or interior of a to-be-modified ion exchange membrane by a target pollutant so as to enable the ion exchange membrane to have a mono-/multi-valent ion selective permeability, so that the mono-/multi-valent ion exchange membrane is obtained. According to the method of the invention, through chemical bond combination between the target pollutant and the ion exchange membrane main structure, the surface resistance is effectively reduced, the limiting current density under electrodialysis operating conditions is improved, and peeling of a modification compound from a membrane matrix is avoided during long-term operation. The method has a simple operation process, is easy to industrialize, has a wide range of raw materials, and has low cost in the membrane modification process.

The invention discloses a platinum alloy catalyst, a preparation method of the platinum alloy catalyst and an application of the platinum alloy catalyst in a fuel cell cathode catalyst. The method comprises the following steps: 1) preparing a mixed solution of a first reducing agent glucose and a precursor of a first metal component platinum; 2) under the condition that the pH value of the mixed solution is 3-10, heating and adding a carbon carrier, and raising the temperature to 80-95 DEG C for reaction; 3) adding a second metal component precursor, and reacting; 4) cooling and separating a reaction product; 5) dissolving the reaction product in water, adding a second reducing agent, heating to 80-95 DEG C, and reacting; 6) cooling and separating a reaction product to obtain a catalyst precursor; and 7) calcining to obtain the platinum alloy catalyst. According to the preparation method, a large amount of organic solvents are not needed, the reaction conditions are mild, non-toxic andmild glucose is used as a main reducing agent in an aqueous solution, and the efficient hydrogen fuel cell catalyst is prepared by introducing a second mild reducing agent for further synergistic dispersion and reduction. Wide application prospects are realized in the field of fuel cell catalysts.

The invention relates to a preparation method of an ionic liquid modified nitrogen-sulfur co-doped graphene oxide composite material. The method comprises the following steps: preparing a dispersion liquid from graphene oxide and deionized water, then mixing 1-aminopropyl-3-alkyl imidazole bromide salt, potassium hydroxide and the graphene oxide dispersion liquid, carrying out a reaction process to obtain a 1-aminopropyl-3-alkyl imidazole bromide salt and graphene oxide composite product, then mixing the product with thiourea, adding a solvent to dissolve the mixture, and reacting at 160-200 DEG C to obtain the composite material. The composite material is loaded on a cathode electrode to serve as a catalyst. The material obtained by the invention has good oxygen reduction catalytic activity and a wide application prospect.

The invention provides an alkaline copper plating solution with a main coordination agent of methylenediphosphonate, and relates to non-cyanide electroplating field. The plating solution comprises the following components: methylenediphosphonate (MDP) with concentration of 30-100 g/L, cupric ion with concentration of 3-25 g/L, and carbonate ion with concentration of 10-80 g/L. By using sodium hydroxide or potassium hydroxide, pH value of the solution is adjusted to 7.5-13.5. The plating solution in the invention has the characteristics of simple formula, no cyanide pollution, small concentration polarization generated in an electroplating process, good stability of the plating solution, and wide allowable current density range. By using the plating solution to plate copper on iron matrix, zinc matrix, zinc alloy matrix or aluminium zinc galvanizing directly, a copper plating layer with good bonding force with the matrix is obtained.

The present invention relates to mechanical apparatus technology, and is especially one kind of high speed electric spray coating apparatus comprising coating solution circulation system, mechanical driving system, microcomputerized circuit control system and control console. Compared with available technology, the present invention has the advantages of novel structure, in which electrolyte is sprayed in certain flow rate and pressure from the nozzle as anode to the workpiece as the cathode to activate the coating mechanically, reduce the thickness of the boundary layer and diffusion layer, speed the stirring of solution, raise the limit current density and raise the deposition speed, high selectivity, quick speed, low cost and no need of mask, etc.

The invention relates to a preparation method of a cathode oxygen reduction reaction catalyst based on a two-dimensional graphite phase carbon nitride cobalt doped porous carbon material. An active substance of a nano material is C3N4@Co-BDC-TA. The problems existing in an existing fuel cell catalyst are solved, the defects in the prior art are overcome, the problems of single precursor obstacle and low synthesis cost of the existing fuel cell catalyst are generally faced, and the defects of high cost, toxicity and the like of a platinum-based catalytic material are overcome; and on the basis of a two-dimensional layered g-C3N4 material, a porous carbon material formed by taking tannin as a connecting agent and fixing metal Co with terephthalic acid is developed, and the porous carbon material has the advantages of relatively high initial potential and half-slope potential, excellent limiting current, excellent stability, good methanol tolerance, relatively high methanol poisoning resistance and the like.

The invention discloses a high-speed copper electroplating solution and a ceramic substrate pattern electroplating method thereof. The solution is an acidic copper sulfate system, and comprises the following main salts according to concentration: 120-150g/L of copper sulfate and 60-80g/L of sulfuric acid; the additive comprises the following components: 6-10 mg/L of an accelerator, 0.3-0.4 g/L of an inhibitor and 50-70 mg/L of chloride ions. When the pattern of the ceramic substrate is electroplated, bubbling, ultrasound and other auxiliary processes for strengthening mass transfer are needed. The electrocoppering solution is simple in component, high in limiting current density, high in current efficiency, safe and environmentally friendly, high-speed copper plating of fine patterns with the line width/line distance of 50-500 micrometers can be achieved under the large current density, the growth rate is larger than 100 micrometers/h, a copper plating layer is bright in surface, uniform in thickness, compact in structure, low in impurity content and high in corrosion resistance, and the electrocoppering effect is good. The method is especially suitable for preparing a metal circuit layer on the surface of a ceramic substrate.

The invention discloses a method for catalyzing ORR reaction based on COFs derived carbon nanotubes, and belongs to the field of electrocatalytic oxygen reduction of cathode parts of fuel cells. Application of the carbon nanotubes derived from the covalent organic frameworks COFs in the catalytic cathode oxygen reduction reaction comprises the following steps that the carbon nanotubes derived fromthe covalent organic frameworks COFs are used as catalysts to be applied to the cathode oxygen reduction reaction, and the adopted carbon nanotubes are derived from the COFs. Regulation and control of ORR activity are facilitated through regular and controllable metal/heteroatom doped or carbon tube diameter and wall thickness, good application prospects are achieved, and the solvothermal preparation method is simple and safe.

The invention discloses a heat treatment process for improving oxygen reduction catalytic activity of a non-noble metal catalyst, which comprises the following steps: step 1, stirring and dispersing an imidazole source at normal temperature, and dissolving in a methanol solvent; 2, stirring and dispersing a metal source at normal temperature, and dissolving the metal source in a methanol solvent; 3, mixing the solutions in the step 1 and the step 2, and carrying out a hydrothermal reaction; 4, carrying out centrifugal separation and centrifugal washing on the catalyst material prepared in the step 3; 5, drying the washed catalyst; and 6, fully grinding the dried catalyst material, and carrying out heat treatment in an inert gas atmosphere. The prepared Fe-N-C catalyst material subjected to low-temperature treatment is excellent in catalytic performance, and possibly has incomparable advantages when being used as a cathode catalyst material of a proton exchange membrane fuel cell. The low-temperature heat treatment mode can be used for reference in other types of Fe-N-C materials.