75results about How to "Small Tafel slope" patented technology

The invention discloses a preparation method of an alpha phase cobaltous hydroxide nanosheet for an oxygen evolution reaction. A cobalt source compound and an alkaline reagent are dissolved into hydrophilic solutions, reflux condensation under microwave heating is carried out after even mixing, natural cooling to the room temperature is carried out, separation is carried out after centrifugal washing, and the alpha phase cobaltous hydroxide nanosheet is obtained after vacuum drying. According to a preparation method, the microwave heating reflux condensation manner is adopted, the preparation method is simple, easy to operate, low in cost and environment-friendly, no special equipment is needed in the overall reaction process, industrial production is facilitated, and finally the obtained product is higher in quality. The alpha phase cobaltous hydroxide nanosheet prepared through the method can have the beneficial effects of being high in material electrical conductivity, many in active site, high in electrocatalytic activity and the like. The material prepared through the method is an ideal oxygen evolution reaction catalytic material with wide commercialization application prospect.

The invention relates to a foamed nickel-based porous NiFe hydrotalcite nanosheet as well as preparation and application thereof. The invention discloses a preparation method of a foamed nickel-basedporous NiFe hydrotalcite nanosheet. The preparation method comprises the following steps that foamed nickel is immersed into a reaction solution, wherein the reaction solution comprises bivalent nickel salt, trivalent iron salt, urea, ammonium fluoride, hydrogen peroxide and water; then a reaction is conducted at the temperature of 100-120 DEG C under the closed condition, so that the foamed nickel-based porous NiFe hydrotalcite nanosheet is obtained after the reaction is completed.

The invention belongs to the field of new energy materials and electrochemical energy conversion devices, and particularly relates to ferrocobalt selenide and a preparation method and application thereof. Ferrocobalt selenide is prepared by means of a two-step hydrothermal method, firstly, a ferrocobalt basic carbonate precursor with a uniform and dense nanosheet shape is prepared by adopting a first-step hydrothermal reaction, and secondly, the precursor is selenized through second-step hydrothermal treatment on the premise of not damaging the uniform and dense nanosheet shape; the preparation method is simple, safe, efficient and controllable. When ferrocobalt selenide is used as an oxygen generating catalyst, since ferrocobalt selenide has a spinel structure, selenized ferrocobalt selenide is a thin nanosheet, more catalytic active sites are exposed, ferrocobalt selenide has high catalytic activity, the starting voltage of the catalyst is low, the overvoltage at a place of 10 mA m<2> is 217 millivolts, and ferrocobalt selenide has electrochemical properties such as lower Tafel slope and good catalytic stability.

The invention discloses a preparation method and application of a VN@WN nanoparticle with an electrocatalysis function. The preparation method comprises the following steps: firstly, grinding a mixture of dicyandiamide, ammonium metavanadate and phosphotungstic acid, carrying out sieving with a 60-mesh sieve to obtain a mixture, putting the mixture into a porcelain boat, putting the porcelain boatinto a tubular atmosphere furnace, and respectively placing two furnace plugs at the two ends of a tube at an interval of 5 cm; introducing inert gas into the tubular atmosphere furnace to exhaust air in the tube, controlling the inner air pressure of the tube to be -1 MPa to 0 MPa, heating the tube to 700 DEG C to 900 DEG C at a heating rate of 10 DEG C/min, and maintaining the tube at the temperature for 120 min to 180 min; and carrying out cooling to obtain a sample and grinding the cooled sample in a mortar to obtain the VN@WN nanoparticle. The VN@WN nanoparticle with the electrocatalysisfunction prepared by using the preparation method is applied to the enhancement of hydrogen production activity. The VN@WN nanoparticle prepared by the method has an electrocatalytic function, can provide a clean and sustainable energy source for electrolysis of water, and is capable of eliminating the obstacle that a high-cost platinum-based material is widely applied to the industry. The electrocatalyst is simple in preparation process, good in hydrogen production performance and good in stability and circularity.

The invention discloses a method for synthesizing high-activity Ni-Mo-Co hydrogen evolution catalyst under the acid environment. The method comprises the following steps: (1) preparing catalyst electroplating liquid; (2) cleaning a substrate; (3) preparing template electrolyte; (4) manufacturing a template; (5) reprocessing the catalyst electroplating liquid; (6) depositing a catalyst. The methodhas the advantages of low cost, simpleness in operation and short period, and the prepared hydrogen evolution catalyst can remarkably reduce hydrogen evolution overpotential and can more remarkably reduce the hydrogen evolution overpotential under the acid environment.

The invention provides a hydrogen evolution electrocatalytic material as well as a preparation method and application thereof. The hydrogen evolution electrocatalytic material contains ultrafine ruthenium nanoparticles with the metal loading capacity of 0.05-5wt% and a nitrogen-doped carbon skeleton with the nitrogen doping capacity of 1.0-10.0 at%, wherein the ultrafine ruthenium nanoparticles are uniformly loaded in the nitrogen-doped carbon skeleton, and the nitrogen-doped carbon skeleton contains a nitrogen element, a carbon element and an oxygen element. The hydrogen evolution electrocatalytic material provided by the invention can catalyze water electrolysis hydrogen evolution reaction, and can ensure the stability of the catalyst material while realizing efficient electrocatalytic hydrogen evolution.

The invention provides an iron-nitrogen co-doped carbon and MXene compound as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing an iron-doped imidazolinate framework; preparing Fe-N-C; mixing Fe-N-C and Ti3C2Tx, dispersing the mixture into N,N-dimethylformamide, and carrying out ultrasonic treatment; carrying out suction filtration, washing and drying, heating to 300 DEG C and 400 DEG C in a nitrogen atmosphere, and carrying out heat preservation for 0.5 hour to 2 hours so as to obtain the iron-nitrogen co-doped carbon and MXene compound FeNC@Ti3C2Tx. The iron-nitrogen co-doped carbon and MXene compound prepared by the preparation method can effectively catalyze an oxygen reduction reaction.

The invention discloses an iron-group carbide nano crystal-graphene nanoribbon composite material as well as preparation and application thereof, and belongs to the technical field of carbon nano materials. Graphene nanoribbon arrays are vertically grown on silicon wafers, iron-group carbide nano crystal is arranged at the top ends of the graphene nanoribbon arrays, and the iron-group carbide nano crystal is one of Fe3C, Co3C and Ni3C. The preparation comprises the following steps: firstly, vertically growing the graphene nanoribbon arrays on the silicon wafers, subsequently, evaporating iron-group elements at the top ends of the graphene nanoribbon arrays, and finally producing the iron-group carbide nano crystal. The iron-group carbide nano crystal-graphene nanoribbon composite material disclosed by the invention can be used in hydrogen evolution catalysis and oxidation reduction catalysis after the silicon wafers at the bottom are removed.

The invention relates to a defect-rich Fe2O3-FeF2 nano porous film, a preparation method and application thereof, and aims to solve the technical problems of complex preparation process, high reactiontemperature, long preparation cycle and high cost in existing hydrogen and oxygen evolution bifunctional electrocatalysts. The technical scheme adopted by the invention includes: firstly conducting anodic oxidation treatment on an ordinary iron foil, then using NH4F as the fluorine source, in an argon atmosphere, carrying out fluorination reaction on the iron foil subjected to anodic oxidation treatment by chemical vapor deposition (CVD) method, and performing natural cooling to room temperature, thus obtaining the Fe2O3-FeF2 nano porous film. According to the invention, the preparation process is simple, only needs anodic oxidation equipment and a CVD furnace, and can complete preparation of the Fe2O3-FeF2 composite nano porous film without special atmosphere and pressure environment, and the obtained Fe2O3-FeF2 nano porous film contains FeF2 and Fe2O3 phases, is rich in defects, and has the advantages of high electrocatalytic hydrogen and oxygen evolution activity, low initial potential, large electric current density, stable performance and the like.

The invention relates to an oxygen evolution reaction FeOOH/Co(OH)2 composite electrocatalyst preparation method. The method adopts cobalt nitrate and ferric nitrate as raw materials to prepare a deposition electrolyte. Constant voltage potential layered deposition is used, and the deposition principle is that cathodic reduction of nitrate to a hydroxide ion is carried out, hydroxide precipitationis formed with a transition metal ion on the surface of a substrate, L-alanine is added to a nitrate electrolyte, and the electrostatic interaction between amphoteric terminal groups and anions and cations in a transition metal salt solution can effectively form nanoparticle growth on substrate carbon fibers during the electrodeposition process. The FeOOH/Co(OH)2 composite electrocatalyst prepared by the invention has high electrocatalytic performance and electrochemical stability, and can be used as an electrocatalytic material in an oxygen evolution reaction in the fields such as development of metal-air cells and clean energy.

The invention discloses a tantalum nitride carbon nano-film integrated electrode with cobalt nano-particles growing in a confinement manner, and a preparation method and an application thereof. The preparation method comprises the following steps: synthesizing a tantalum oxide nano-film taken as a carrier, loading a Co(tzbc)2(H2O)4 complex on the carrier through a hydrothermal technology, carryingout a nitridation reaction on the synthesized composite material through a chemical vapor deposition (CVD) technology, and naturally cooling the obtained reaction product to room temperature to prepare the tantalum nitride carbon nano-film integrated electrode with cobalt nano-particles growing in the confinement manner. The preparation process is simple, and the preparation of the tantalum nitride carbon nano-film integrated electrode with cobalt nano-particles growing in the confinement manner can be completed through a CVD furnace without a special pressure environment. The prepared tantalum nitride carbon nano-film integrated electrode with cobalt nano-particles growing in the confinement manner has electro-catalytic hydrogen evolution and oxygen evolution properties at the same time.

The invention provides a molybdenum carbide nanorod for a catalyst and a preparation method and application of the molybdenum carbide nanorod. The preparation method disclosed by the invention comprises the following steps of: dispersing molybdenum trioxide and hypoxanthine in deionized water to obtain a dispersion liquid, carrying out a hydrothermal reaction on the obtained dispersion liquid, naturally cooling the obtained dispersion liquid to room temperature after the reaction is finished, successively conducting centrifuging, washing and drying to obtain a precursor nanorod, calcining theprecursor nanorod under inert gas, and conducting natural cooling to room temperature to obtain the molybdenum carbide nanorod. The molybdenum carbide nanorod prepared by the invention shows excellenthydrogen evolution reaction catalytic performance in an alkaline medium, and has relatively small overpotential and Tafel slope. The method has the advantages of simple preparation process, low cost,no use of reagents with strong toxicity and great harm to the environment, no pollution to the environment, greenness, environmental protection, suitableness for industrial production, and very goodlarge-scale commercial preparation and application prospect.

The invention provides a preparation method of an iron-based MOFs oxygen evolution electrocatalyst with a high-activity crystal face proportion, and the catalyst, and belongs to the technical field of oxygen evolution electrocatalysts. The method comprises the following steps: weighing ferric salt and an organic ligand fumaric acid according to the molar ratio of iron ions to fumaric acid of 1: (64-128), dissolving the ferric salt and the organic ligand fumaric acid in an N, N-dimethylformamide solvent, and uniformly stirring to obtain a mixed solution; carrying out solvothermal reaction on the obtained mixed solution at a certain reaction temperature for a period of time, and naturally cooling to room temperature; and washing the obtained product with absolute ethyl alcohol, and then drying and collecting to obtain the product which is the iron-based MOFs oxygen evolution electrocatalyst. The iron-based MOFs electrocatalyst with the high active crystal face exposure proportion can be synthesized in situ by regulating and controlling the proportion of the metal Fe ions and the organic ligand fumaric acid and using a mild solvothermal method, the preparation method is mild, simple and easy to operate, and the purpose of regulating and controlling the crystal face can be achieved without additionally introducing a surfactant.

The invention discloses a ternary layered carbide Mo2Ga2C composite flower-like MoS2 nano-particle composite material and a preparation method and application thereof. According to the composite material, flower-like MoS2 nanoparticles are used as compounds, ternary layered carbide Mo2Ga2C is used as a carrying substrate material, the ternary layered carbide Mo2Ga2C has a length of about 5 [mu]m and a width of about 3 [mu]m, and is a hexagonal crystal phase layered skeleton material, two Ga layers are stacked between Mo2C layers in a simple hexagonal arrangement, the closely packed Mo atoms are interleaved with the double layers of Ga to form a Mo-Mo-Ga-Ga-Mo-Mo layer, the two Ga layers lie exactly on tops without being closely packed, the carbon atoms occupy octahedral position points among the Mo atoms, and the flower-like MoS2 nanoparticles are uniformly distributed on the surface of the layered Mo2Ga2C to form a stable carrying structure. The invention further discloses a preparation method of the composite material. The preparation method is low in cost, simple in preparation condition and high in repeatability. The invention also provides an application of the nano material as a water splitting catalytic electrode, and the electrode material has the advantages of high conductivity, strong cycling stability and the like.

The intention relates to a Co@ FePx-NCs material for alkaline solution hydrogen evolution and a preparation method and application thereof. The method comprises the steps that firstly, ferric chloride, sodium hypophosphite, dicyandiamide and ethyl alcohol are mixed and prepared into a solution, then a cobalt source is added into the solution and mixed evenly, and a mixed solution is obtained; by heating and evaporating the mixed solution to dryness, a CoPx/FePx-C2N4H4 mixture is obtained, finally by soaking the CoPx/FePx-C2N4H4 mixture in a phosphoric acid solution for etching, and sequentially filtering, drying and calcining, the Co@ FePx-NCs hydrogen evolution material is obtained. The Co@ FePx-NCs material can be used for electrocatalytic hydrogen evolution reaction. Compared with the prior art, the preparation method is simple, the raw material cost is low, the earth reserve of main elements is sufficient, the electrochemical performance of the electrode material is improved through the composite effect of two transition metals, and the Co@ FePx-NCs material has a wide industrial application prospect.

The invention provides a FeCu-N-HC nanosphere catalyst and a preparation method thereof, and belongs to the field of air battery catalytic materials. The preparation method comprises: firstly formingFeCu-N coordination, physically mixing NaCl and SiO2 nanosphere templates, then preparing the FeCu-N6-containing hollow carbon nanospheres through carbonization, and the BET specific surface area being 610 m<2> g<-1>. Due to the fact that the Fe-Cu synergistic coordination ligand is formed firstly, when oxygen reduction catalysis is conducted on the finally-prepared FeCu-N6, the catalysis steps can be effectively shortened, and the catalysis rate of active sites is increased. The FeCu-N-HC hollow carbon nanosphere prepared by the method is used as an oxygen reduction catalyst, and the catalytic performance and the stability of the FeCu-N-HC hollow carbon nanosphere are superior to those of a current commercial 20% Pt/C catalyst.

The invention discloses a preparation method and application of an iron-nickel-doped tantalum nitride carbon nano-film integrated electrode. The method comprises the following steps: synthesizing a tantalum oxide nano-film, taking the tantalum oxide nano-film as a carrier, loading ferric hydroxide and nickel hydroxide through a hydrothermal method, carrying out a nitridation reaction on the synthesized composite material through a chemical vapor deposition (CVD) method, and naturally cooling to room temperature to prepare the iron-nickel-doped tantalum nitride carbon nano-film integrated electrode. The preparation process is simple, and the preparation of the iron-nickel-doped tantalum nitride carbon nano-film integrated electrode can be completed through a CVD furnace without a special pressure environment. The prepared iron-nickel-doped tantalum nitride carbon nano-film integrated electrode has electro-catalytic hydrogen evolution and oxygen evolution performances at the same time.