14 results about "Cobalt selenide" patented technology

The application discloses a preparation method of amorphous MOF derived ZIF and application thereof, and the preparation method comprises the following steps: preparing zinc nitrate hexahydrate and cobalt nitrate hexahydrate into solution A, preparing 2,5-dihydroxyterephthalic acid into solution B, carrying out a solvothermal reaction of solution A and solution B to obtain amorphous ZnCo-MOF powder; preparing the amorphous ZnCo-MOF powder into suspension C, dissolving 2-methylimidazole in an ethanol aqueous solution, adding triethylamine to form solution D, adding the suspension C into the solution D to react to obtain ZnCo-ZIF hollow nanosphere powder; placing the ZnCo-ZIF hollow nanosphere powder into argon for annealing treatment to obtain nitrogen-doped porous carbon hollow nanosphere material; uniformly mixing the nitrogen-doped porous carbon hollow nanosphere powder with selenium powder, and then placing the mixture into argon for annealing treatment to obtain zinc selenide / cobalt selenide@nitrogen-doped porous carbon hollow nanosphere material. The zinc selenide / cobalt selenide@nitrogen-doped porous carbon hollow nanosphere prepared by the method is mainly applied to preparation of a negative electrode material of a high-performance sodium ion battery.

The application provides a sulfur-doped C3N4-CoSe2 lithium-sulfur battery positive electrode catalyst and a preparation method and application thereof, and belongs to the technical field of nanometer material preparation. First, citric acid, thiourea, a cobalt salt, selenium powder and ethanol are ultrasonically mixed to obtain a slurry material, and then the slurry material is subjected to joule heat shock in an air atmosphere to obtain a two-dimensional sulfur-doped C3N4-CoSe2 lithium-sulfur battery positive electrode catalyst. The catalyst can fully exert the synergistic effect of the structural and component advantages, the two-dimensional structure endows it with a large specific surface area, meanwhile, the two-dimensional channel can promote the migration of particles and inhibit the shuttle effect of polysulfides, and the C3N4 and sulfur doping together endow it with the component advantages, wherein the C3N4 can effectively stabilize the structure of cobalt selenide, together with the sulfur doping, the catalytic activity and conductivity of the cobalt selenide are improved, the conversion of polysulfides is promoted, thereby the shuttle effect of the lithium-sulfur battery is inhibited and the stability of the cobalt selenide is improved, and excellent lithium-sulfur battery performance is exhibited.

This invention relates to a method for preparing cobalt selenide rich in double defects and its application in the electrocatalytic reduction of oxygen to hydrogen peroxide. First, selenium powder is mixed with sodium hydroxide solution to obtain material A. Cobalt salt is mixed with EDTA-2Na solution to obtain material B. Material B and material A are then mixed and subjected to a hydrothermal reaction. The resulting product is centrifuged, washed, and vacuum dried to obtain cobalt selenide powder. The cobalt selenide powder is dispersed in anhydrous ethanol, and then potassium thiocyanate powder is added. After vigorous stirring, ultrasonic exfoliation is performed. The product is centrifuged, washed, dried, and calcined to obtain cobalt selenide rich in double defects. This invention provides a simple preparation method that can rapidly and cost-effectively prepare double-defect cobalt selenide under mild conditions. The obtained double-defect cobalt selenide can effectively reduce oxygen to hydrogen peroxide under electrocatalytic conditions, solving the problems of high price and low efficiency of current catalysts for hydrogen peroxide production under acidic conditions.

The application provides a three-dimensional flower-shaped silicon@zinc selenide / cobalt selenide@carbon composite material and a preparation method thereof, a lithium ion battery silicon-based negative electrode and a battery. Compared with the prior art, the silicon particles are first prepared to grow in nanometer flower sheets, then the silicon particles are carbon-coated, and then the silicon particles are put into a tube furnace to be converted into the Si@ZnSe / CoSe@C composite material by using selenium powder. The flower-shaped structure can not only increase a large number of surface active sites but also effectively relieve the volume expansion of the silicon particles, so that the cycle stability of the battery is improved, and the battery obtains an extremely high specific capacity.

The application belongs to the technical field of two-dimensional nanomaterial electrocatalyst preparation, and particularly relates to an amorphous Sr-CoOOH v Ultra-thin nanosheet electrocatalyst, preparation method and application. Strontium-doped cobalt selenide nanobelt is prepared as a substrate by a hydrothermal method, and in-situ electrochemical reconstruction is generated under alkaline electrolytic water anode oxygen evolution reaction conditions. The Sr-CoOOH v The ultra-thin nanosheet can not only enhance cobalt-oxygen covalence to activate lattice oxygen, but also improve hydroxyl affinity to fill lattice oxygen due to the existence of metal cobalt vacancies, so that the catalyst exhibits excellent catalytic activity and durability in industrial application of anion exchange membrane electrolytic water hydrogen production.

The invention discloses a Cr-doped cobalt selenide-based water electrolysis catalyst and a preparation method thereof, and belongs to the field of water electrolysis catalysts. The chemical formula of the Cr-doped cobalt selenide-based water electrolysis catalyst is Crx-CoSe2, 0.1 lt, and the chemical formula is as shown in the specification. Xlt; the particle size of the catalyst is 6 to 70 [mu] m. The preparation method of the catalyst comprises the following steps: (1) cleaning a foamed nickel base material to obtain pretreated foamed nickel; (2) sequentially adding Co (NO3) 2.6 H2O, Cr (NO3) 3.9 H2O and CO (NH2) 2 into water, and stirring until solids are completely dissolved; (3) putting the solution obtained in the step (2) into a reaction kettle in which pretreated foamed nickel is inserted, and carrying out hydrothermal reaction to obtain a precursor; and (4) calcining the precursor and selenium to obtain the catalyst. The catalyst provided by the invention can achieve the effects of low cost, high activity and high stability.

The invention belongs to the technical field of potassium ion battery negative electrode materials, and particularly relates to a tomato-like cobalt diselenide / carbon composite material and a preparation method and application thereof.The preparation method comprises the steps that firstly, a cobalt precursor is prepared through a hydrothermal reaction, then the cobalt precursor, tris (hydroxymethyl) aminomethane and an oxygen-containing carbon source are dissolved in a homogeneous solution to be subjected to a coating reaction, and the tomato-like cobalt diselenide / carbon composite material is obtained; the core-shell structure material with the cobalt precursor coated with the polymer is obtained; and dispersing the core-shell structure material in a selenylation solution for hydrothermal reaction to obtain a polymer-coated cobalt diselenide black powder material, and calcining the polymer-coated cobalt diselenide black powder material in an inert atmosphere to obtain the tomato-like cobalt diselenide / carbon composite material. According to the method, zinc salt does not need to be introduced as a template, the process is simple, the synthesis cost is low, and the prepared tomato-like cobalt diselenide / carbon composite material has good conductivity and stability and is suitable for potassium ion batteries.

This invention relates to a composite anode material, its preparation method, and a battery. The composite anode material has a hollow core-shell structure. From its center to its outer surface, the composite anode material sequentially includes a cobalt selenide sulfide layer and a hard carbon coating layer, with the cobalt selenide sulfide layer enclosing a cavity. The thickness of the cobalt selenide sulfide layer is 30%–65% of the total thickness from the center to the outer surface of the composite anode material (assuming 100% thickness). The cobalt selenide sulfide layer includes an outer shell layer and a core layer. The outer shell layer is in contact with the hard carbon coating layer, and the core layer is in contact with the cavity. The thickness of the outer shell layer and the core layer are both 10%–25% of the total thickness (assuming 100% thickness). The chemical formula of the cobalt selenide sulfide is CoS. x Se 2‑x The values ​​of x are 0.3 ≤ x ≤ 1.7, and the x value decreases from the core layer to the outer shell layer. This composite anode material exhibits excellent structural stability, low expansion, high conductivity, and good cycle stability and rate performance.

The application belongs to the technical field of battery materials, and relates to a preparation method and application of a silicon-based composite material. The preparation method comprises the following steps: dissolving a PDDA solution in water and ethanol, adding nano-silicon powder, and then adding selenium dioxide and stirring uniformly; subsequently, a cobalt source, a nickel source and a reducing agent are added, and pH is adjusted to obtain a precursor solution; the precursor solution is subjected to hydrothermal reaction, and after centrifugation, washing, filtration and drying, a Si / Ni y Co (1‑y) Se x nanowire powder sample; after the powder sample is ground and sieved, chemical vapor deposition is performed to grow carbon nanotubes on the surface of the nanowires, and finally, the silicon-based composite material is obtained. In the silicon-based composite material, the surface of the nano-silicon particles is uniformly distributed with nickel-cobalt selenide nanowires and carbon nanotubes, the two are interwoven to form a cage-like conductive network structure, the nano-silicon particles are effectively coated and fixed, and therefore the overall electrochemical performance of the composite material is greatly improved.

The application relates to the technical field of supercapacitor electrode materials, in particular to a sulfur-doped nickel cobalt selenide composite material and a preparation method and application thereof. The preparation method comprises the following steps: taking SeO2 as a selenium source, taking hydrazine hydrate as a strong reducing agent, mixing a SeO2 ethylene glycol solution with the hydrazine hydrate and a NiCo-PBA@NiCo-LDH multi-level core-shell precursor, and performing a selenization reaction to obtain NiCoSe2; mixing the NiCoSe2 with sulfur powder, and performing calcination treatment to obtain the sulfur-doped nickel cobalt selenide composite material. Through the synergistic effect of the multi-level core-shell structure and the hetero-doping, the sulfur-doped nickel cobalt selenide composite material is endowed with excellent electrochemical energy storage performance, and the problems of poor rate performance and decreased cycle stability caused by the insufficient intrinsic electrochemical activity and large volume change in the charging and discharging process of the transition metal selenide as a supercapacitor electrode material are effectively solved.

The invention belongs to the technical field of preparation of two-dimensional nano material electrocatalysts, and particularly relates to an amorphous Sr-CoOOHv ultrathin nanosheet electrocatalyst as well as a preparation method and application thereof. The strontium-doped cobalt selenide nanobelt is prepared through a hydrothermal method to serve as a substrate, and in-situ electrochemical reconstruction is carried out under the alkaline electrolyzed water anode oxygen evolution reaction condition to obtain the strontium-doped cobalt selenide nanobelt. According to the Sr-CoOOHv ultrathin nanosheet rich in cobalt vacancies, due to the existence of the metal cobalt vacancies, cobalt-oxygen covalence can be enhanced, lattice oxygen can be activated, meanwhile, hydroxyl affinity can be improved, and the lattice oxygen can be filled, so that the catalyst shows excellent catalytic activity and durability in industrial application of anion exchange membrane water electrolysis hydrogen production.

This invention relates to a method for preparing and applying a cobalt-deficient cobalt selenide-anchored high-loading Pt single-atom catalyst. Selenium powder is mixed with sodium hydroxide solution to obtain material A. Cobalt salt is mixed with EDTA-2Na solution to obtain material B. Material B and material A are mixed and subjected to a hydrothermal reaction. The resulting product is centrifuged, dried, and dispersed in anhydrous ethanol. Potassium thiocyanate powder is then added, and the mixture is ultrasonically exfoliated, centrifuged, washed, dried, and calcined to obtain Co-deficient cobalt selenide. This cobalt selenide is uniformly dispersed in an ammonium hydroxide aqueous solution. Under alkaline conditions, an ammonia solution containing tetraammineplatinum nitrate is added, and the reaction is carried out at room temperature for 24 hours. After centrifugation, washing, drying, and calcination, the desired product is obtained. This invention provides a simple preparation method that enables rapid and low-cost preparation of Co-deficient cobalt selenide under mild conditions. The Co-deficient cobalt selenide can anchor high-loading Pt single atoms, improving the stability of the Pt single atoms and thus enhancing the catalytic activity and selectivity of the catalyst for oxygen reduction to H₂O₂.

The invention discloses a preparation method and application of a cobalt selenide heterostructure Co-CoSe C lithium-sulfur battery composite material with a hollow reticular spherical structure, and belongs to the technical field of electrode materials. The material takes a hollow carbon sphere as a main body, and a Co-CoSe-C heterostructure is formed inside the hollow carbon sphere. The preparation method comprises the following steps: dispersing a cobalt source into carbon spheres by an excessive impregnation method, and loading heterostructure particles on carbon nanotubes grown in the carbon spheres by a vapor deposition method to obtain the hollow reticular spherical Co-CoSe-C heterojunction host. The method is short in process, simple in process and good in repeatability. Due to the unique staggered network structure of the obtained material, an additional active material can be anchored to the carbon nano tube in the shell layer, the contact area between a catalytic host and an active substance is increased, the size of the active substance in a sphere is reduced, and the chemical adsorption capacity and catalytic activity to polysulfide are remarkably improved; the shuttle effect is effectively relieved; and the reaction kinetics of the lithium-sulfur battery is improved.

The invention discloses a cobalt / cobalt selenide / cobalt telluride heterojunction composite material and a preparation method and application thereof, and belongs to the technical field of nano material preparation. The preparation method comprises the following steps: adding cobalt salt into a glycerol / isopropanol mixed solvent to prepare a solution, and carrying out hydrothermal reaction on the solution to obtain a precursor A; the precursor A and selenium powder are separately placed, the selenium powder and the precursor A are sequentially arranged in the airflow direction, high-temperature calcination treatment at the temperature of 900-1200 DEG C is conducted in the reducing atmosphere, and a product B is obtained; and the product B and tellurium powder are placed separately, the tellurium powder and the product B are sequentially arranged in the airflow direction, low-temperature calcination treatment at the temperature of 300-500 DEG C is conducted in the inert atmosphere, and the cobalt / cobalt selenide / cobalt telluride heterojunction composite material is obtained. In the preparation process, materials with different heterostructures can be derived in situ only by virtue of derivation rules of the materials in high-temperature and low-temperature modification processes, so that the problems of uncontrollable structure, low catalytic activity, difficulty in large-scale production and the like in the traditional heterostructure preparation process are solved, and the obtained material shows good catalytic performance and is suitable for industrial production. And the catalyst shows obvious prospects in application in scenes needing catalysis, such as lithium-sulfur batteries and lithium-oxygen batteries.