47 results about "Cobalt(II) oxide" patented technology

The invention provides a cobaltous oxide slice. The cobaltous oxide slice is of a zinc blende structure, and has a nanosheet morphology. The invention discloses a method for preparing the zinc blende-type CoO ultrathin slice, which comprises the steps: dispersing sodium chloride and cobalt acetate in water for a reaction so as to obtain a precursor, and calcining the precursor at a specific temperature in an inert atmosphere so as to obtain the zinc blende-type CoO ultrathin slice. The invention also provides a method for achieving visible-light total decomposition of water by using the zinc blende-type CoO ultrathin slice. It is shown through experimental results that the zinc blende-type CoO ultrathin slice has higher performance in visible-light total-decomposition of water and higher stability than rock salt-mine-type CoO ultrathin sheets, and the formation rates of H2 and O2 under irradiation of visible light by means of the cobaltous oxide slice are 4.43 [mu]mol.g<-1>.h<-1> and 2.63 [mu]mol.g<-1>.h<-1> separately.

The invention relates to the technical field of cobalt-based powder material preparation, in particular to a preparation method of superfine spherical cobalt powder. The method comprises the followingsteps that (1), a cobalt salt solution reacts with an ammonium bicarbonate or sodium carbonate precipitant under a heating condition to obtain cobalt carbonate precipitate; (2), the cobalt carbonateprecipitate is filtered, washed with pure water, and dried to obtain cobalt carbonate powder; (3), the cobalt carbonate powder is placed into a calcining furnace, and heated and decomposed in an oxygen-free state to obtain cobaltous oxide; (4), the cobalt monoxide powder obtained by calcining and decomposing is placed into a reduction furnace, and hydrogen is introduced for reduction to obtain a loose spongy cobalt block; and (5), airflow milling is carried out on the spongy cobalt block in a closed cycle inert gas protective atmosphere to obtain the ultrafine spherical cobalt powder with theFisher particle size being 0.4-0.8 micrometer. The particle size of the prepared cobalt powder reaches the ultrafine grade, the cobalt powder is spherical, and the cobalt powder has the advantages ofbeing uniform and controllable in particle size, uniform in particle size distribution, good in flowing property and the like.

The invention relates to the field of production of chemical raw materials, in particular to a cobalt powder preparation method. The cobalt powder preparation method includes the following steps that sulphuric acid is added into lithium cobalt paper for acidolysis of the lithium cobalt paper; after the pH value is regulated to 1 to 3, copper impurities are removed; hydrogen peroxide is added, then the pH value is regulated to 2 to 5, and filter pressing is performed to remove impurities; purification and reaction are carried out to obtain a cobalt nitrate solution; the cobalt nitrate solution reacts with ammonium carbonate to obtain cobalt carbonate; the cobalt carbonate is dried, calcined and cooled to obtain the cobalt powder. According to the preparation method, liquid caustic soda is not needed to treat the lithium cobalt paper, the reducing agent sulfur dioxide does not need to be added in the acidization either, and sodium carbonate is replaced with the ammonium carbonate in the cobalt precipitating process; the cobalt powder is produced and prepared through the lithium cobalt paper, so that production cost is greatly reduced, and environmental pollution is avoided; moreover, the prepared cobalt powder has very high hardness and compressive strength so that the cobalt powder not only can be used as the catalyst of secondary batteries but also can be applied to hard alloy additives and has a wider application range than cobalt oxide.

The invention discloses a preparation method of spherical cobaltous oxide, and relates to cobalt solution which is obtained by the leaching and purification of cobalt ore that is used as cobalt raw material. The invention is characterized in that a precursor is prepared by a complexing-homogeneous precipitation method, that is the cobalt solution is made into complexing cobalt salt solution whichis then added with precipitator solution, thereby, the precipitate precursor is formed by controlling the synthesis of the precursor; the spherical cobaltous oxide is obtained by the thermal decomposition of the precursor at 300 to 550 degrees under inert or slight reducing gas atmosphere; and then spherical cobaltous oxide of the invention is formed through the associated passivation of the obtained spherical cobaltous oxide by using gas passivator and liquid passivator, and heat seal packing. The cobaltous oxide powder which is obtained by adopting the method of the invention has the advantages of high activity, high purity, uniform particle size, centralized distribution, smooth surface of particles and strong inoxidability, etc. The invention has easy technology flow, stable production quality, low cost, high automation, thereby being applicable to the large-scale industrialized production.

The invention discloses a preparation method of cobalt oxide powder and relates to a preparation method of the cobalt oxide powder in the fields of lithium ion battery cathode materials, fuel cells, catalysts, magnetic materials, electronic ceramics and the like. The method is characterized in that: solution of cobalt salt is atomized in the preparation process and thermally decomposed at a high temperature so as to obtain the cobalt oxide powder. In the method of the invention, the solution of cobalt salt serving as a raw material is atomized, the cobalt salt is thermally decomposed at a high temperature and under a controllable atmosphere so as to generate cobalt oxides (comprising cobalt monoxide CoO, cobaltosic oxide Co3O4 and cobalt sesquioxide Co2O3) and produced tail gas is absorbed to form regeneration acid. The method can further continuously realize a preparation process from solution to a cobalt oxide; and the particle size of the cobalt oxide powder prepared by the method is controllable in the range of between 0.2 and 20 microns and the cobalt oxide powder has uniform particle size distribution and high electrochemical performance. The preparation method saves energy, protects the environment and has low production cost and remarkable economic and social benefits.

The invention discloses a method for producing nanoscale cobalt (II) oxide, particularly a production method of cobalt (II) oxide used as a cathode material of secondary batteries. The nanoscale cobalt (II) oxide is prepared from raw materials including cobalt nitrate crystals, 150 L of aqueous ammonia with the concentration of 180 g / L, 1800 L of sodium hydroxide with the concentration of 130 g / L, dilute aqueous ammonia with the concentration of 10%, and the like through the steps of dilution, dissolution, synthesis, deposition, filtration, slurrying, washing, drying, semi-reduction decomposition under the positive pressure atmosphere, passivation through inert gases, sieving and the like. The prepared nanoscale cobalt (II) oxide with the particle size being only 0.1-0.5 micron is relatively narrow in particle size distribution, uniform in particle size and good in dispersion effect. The secondary batteries produced through adopting the cobalt (II) oxide as the cathode material of secondary batteries is relatively short in charging time, and particularly, the charge and discharge capacity of the secondary batteries reaches up to 90% at the low temperature of minus 40 DEG C, so that the service life of the secondary batteries is relatively long.

The invention discloses cobalt monoxide for a catalyst and a preparation method and an application thereof. The preparation method thereof comprises the following steps: using cobalt acetylacetonate as a cobalt source, and using ionic liquid as a solvent, wherein the ionic liquid is 1-butyl-3-methyl imidazole ditrifluoromethyl sulfonimide salt, reacting in an inert gas atmosphere by using an ion hot method, and preparing a precipitate, namely the cobalt monoxide for the catalyst. The prepared cobalt monoxide has an ultrathin sheet-like structure, and has the higher oxygen evolution reaction electrocatalytic activity because more catalytic activity sites can be exposed. In addition, the preparation process is simple, suitable for performing industrial production, and has the potential practical application value in the field of oxygen evolution reaction electrocatalysts.

A dielectric ceramic material and a preparation method thereof. The dielectric ceramic material contains titanium dioxide and cobaltous oxide. The quality factor Q value of the dielectric ceramic material is high, and the compactness is high. At the same time, the temperature during heating and sintering is also reduced; because it contains titanium dioxide and cobaltous oxide, the temperature coefficient of the resonant frequency of the material can be effectively improved.

The invention provides a method for preparing cobaltous oxide nanocrystals and the prepared cobaltous oxide nanocrystals. The preparation method comprises the following steps: using cobalt salt and triphenylphosphine as precursors, completely dissolving the precursors in oleylamine, reacting in a closed environment for 10-20 hours, washing and drying to obtain cobaltous oxide nanocrystals, The reaction temperature is 120-180°C, the purity of the cobalt salt is ≥99.5%, and the mass ratio of the cobalt salt to triphenylphosphine is ≥1:10. In the preparation method of cobaltous oxide nanocrystals of the present invention, cobaltous oxide nanocrystals are prepared by hydrothermal reaction of specific purity cobalt salt and triphenylphosphine under certain temperature conditions, with complete grain development, uniform particle size distribution, and There is less agglomeration, and the reaction raw materials of the preparation method of the present invention are easy to obtain, the production cost is low, the uneven particle size distribution and the mixing of impurities caused by the sintering process are avoided, and the industrial production is easy.

The invention provides a preparation method of cobalt oxide nanocrystal and the prepared cobalt oxide nanocrystal. The preparation method comprises the following steps of using cobalt salt and triphenylphosphine as precursors, completely dissolving the precursors into oil amine, reacting for 10 to 20h under the closed environment, washing and drying, so as to obtain the cobalt oxide nanocrystal, wherein the reaction temperature is 120 to 180 DEG C, the purity of the cobalt salt is greater than or equal to 99.5%, and the mass ratio of the cobalt salt to the triphenylphosphine is greater than orequal to 1:10. The preparation method of the cobalt oxide nanocrystal has the advantages that the cobalt salt and triphenylphosphine with certain purity are performed with hydrothermal reaction undercertain temperature condition, so as to obtain the cobalt oxide nanocrystal; the development of the crystal grain is complete, the granularity distribution is uniform, and the degree of agglomerationbetween the particles is low; the reaction raw materials are easy to obtain, the production cost is low, the problems of nonuniformity of particle size distribution and mixing of impurities due to sintering process are solved, and the industrialized production is easy.

The invention relates to a cobaltous oxide photocatalytic material with high photoelectrocatalytic activity and a preparation method thereof. According to the method, a precursor is prepared from a cobalt oxalate aqueous solution and a sodium hydroxide aqueous solution, and the cobaltous oxide is prepared through microwave hydrothermal treatment, drying and high-temperature treatment. The invention provides a novel synthesis method of cobaltous oxide powder with a controllable grain size. The method can significantly improve the photocatalytic reaction activity of the material. The cobaltous oxide powder produced by the method is expected to be further applied in the field of photocatalysis. The production method is low in cost and simple and convenient in synthesis process, can be applied to mass production, and effectively saves the production cost. The cobaltous oxide powder prepared by the method has excellent photoelectrocatalytic activity and has a relatively large commercialization prospect.

A method for preparing a monocrystalline porous cobalt(II) oxide (CoO) nanorod array is as follows: a growth substrate with a prepared Zn seed layer is placed at 400-500 DEG C for annealing for 0.15-1h; a 0.1-0.5M ZnO hydrothermal growth liquid is prepared; the annealed growth substrate is placed in a reactor, the growth substrate of the annealed growth substrate is tilted down, the ZnO hydrothermal growth liquid is added, the reactor is placed in a cylinder and sealed, the cylinder is placed in a 100 DEG C constant temperature drying oven for preparation of ZnO nanorod arrays; the growth substrate is then placed at 500 DEG C for annealing for 1h; the annealed growth substrate is placed at the center of a tube furnace, CoCl2 powder is used as a Co evaporation source, the tube furnace is vacuumized to 0.1-0 .5Torr, then a carrier gas is introduced into the tube furnace, and the tube furnace is heated to 400-700 DEG C, and thermally insulated for 0.1-1h to obtain the monocrystalline porous cobalt(II) oxide (CoO) nanorod array very conducive to gas adsorption. The monocrystalline porous cobalt(II) oxide (CoO) nanorod array is stable in process, well universal, and suitable for the majority of flexible substrates and conductive substrates, makes industrially practical application possible, and has good application prospects in the fields of fuel cells, catalysis, and the like.

The invention belongs to the field of metal inorganic oxide adsorption materials, and discloses a nanometer carbon-coated cobaltous oxide, a preparation method and an application thereof. The citric acid and cobalt acetate were ultrasonically dissolved in water, and the resulting mixed solution was dried to a colloidal state, and then heated in Ar / H 2 Under the protection of a mixed atmosphere, the temperature is raised to 400-500° C. for roasting treatment, cooled to room temperature, and the obtained product is ground to obtain a nanometer carbon-coated cobaltous oxide material. The preparation process of the present invention is simple, the raw material is economical, and is applicable to large-scale production. The obtained nano-carbon-coated cobaltous oxide for removing tetracycline has the characteristics of short adsorption equilibrium time and high adsorption capacity, and has the characteristics of convenient recovery and recycling use.

The invention discloses a nitrogen-doped graphene / cobaltous oxide composite material. Graphite oxide, a cobaltous acetate solution and ammonium carbonate are taken as the main raw materials, and cobaltous oxide is loaded on nitrogen-doped graphene by adopting a water bath-hydrothermal-calcining method to obtain the nitrogen-doped graphene / cobaltous oxide composite material. Compounding of nitrogen-doped graphene and cobaltous oxide is proposed initially in the invention, the obtained composite material is high in cobaltous oxide purity, and a synergistic effect between cobaltous oxide and nitrogen-doped graphene can be achieved, so that an excellent catalytic ability on a fuel cell negative electrode oxygen reduction reaction can be achieved; meanwhile, the material cost of a catalyst is greatly lowered; and the involved preparation method is simple, high in repeatability and suitable for popularization and application.

The embodiment of the invention provides a cobaltous oxide nanocrystal-graphene composite material. The embodiment of the invention further provides a preparation method of the composite material. The method comprises the following steps of (1) adding graphite oxide to a first organic solvent and dispersing the graphite oxide; (2) adding cobalt acetylacetonate and octadecylamine, heating a mixture to 120-140 DEG C, maintaining the temperature for 20-50 minutes, carrying out heating until the solution boils and reflows and maintaining the temperature for 1-5 hours; (3) adding the mixture to a second organic solvent to suddenly stop the reaction, separating solids and washing and drying the solids; and (4) carrying out thermal treatment on the dried solids in an inert gas for 1-3 hours. The embodiment of the invention further provides an application of the composite material in an organic system Li-O2 battery as an anode catalyst. According to the composite material provided by the embodiment of the invention, cobaltous oxide nanocrystal uniformly grows on a graphene substrate, the dispersity is good and the agglomeration phenomenon is avoided, so that the catalytic performance of the composite material is relatively good.