1083 results about "Cobalt ions" patented technology

The present invention relates to a preparation method for a nickel-manganese-cobalt anode material of a lithium ion battery. According to the present invention, in the presence of nitrogen atmosphere, a mixed solution containing nickel iron, manganese iron and cobalt ion reacts with a precipitating agent, then processes of aging, washing, drying and the like are performed to obtain a nickel-manganese-cobalt hydroxide precursor, the synthesized precursor material has spherical morphology, ideal particle size distribution and high tap density; the precursor, a lithium compound and a doped compound are mixed, then the sintering processing is performed for twice to prepare the nickel-manganese-cobalt three-element composite anode material. The method has characteristics of simple synthesis process, easy process controlling, low energy consumption, high efficiency and low cost, and is applicable for the industrial production; the prepared precursor material has characteristics of spherical morphology, uniform particle distribution and high tap density; the discharge capacity of the battery is improved through doping the metals; the cycle performance of the battery is stable.

The invention discloses a technological method for preparation of sphere-shaped ultrafine metallic powders through hydro-thermal treatment, which relates to a technological method for preparation of sphere-shaped ultrafine nickel powders or ultrafine cobalt powders through the procedures such as precipitation, dispersing agent surface finish, high-pressure hydro-thermal treatment, washing, drying and high-temperature hydrogen reduction and the like, and which belongs to the technical field for preparation of metal powder materials. The technological method adopts water soluble salts with nickel and cobalt, cobalt oxide, sub-carbonate, carbonate or hydroxide as raw materials, which are prepared into water solution after processing, the dispersing agent is added, then nickel ion and cobalt ion in the water solution are precipitated through alkali, carbonate, oxalic acid or ammonium oxalate and the like, the hydro-thermal treatment of water pulp of the precipitate is performed in an autoclave, and products of sphere-shaped ultrafine nickel powders or ultrafine cobalt powders with even graininess and good dispersibility can be obtained through washing, drying and high-temperature hydrogen reduction. The technological method is not only suitable for medium- and small-scale discontinuous-type manufacture, but also used for large-scale continuous manufacture, and the manufacturing cost is low.

The invention discloses a preparation method of a cobalt electro-catalysis oxygen reduction material wrapping a nitrogen-doped carbon nanotube. The method includes the following steps of making melamine, cobalt nitrate hexahydrate and glucose react to obtain a self-assembled melamine precursor, and baking the self-assembled melamine precursor to obtain a cobalt nanoparticle hybrid material electro-catalysis oxygen reduction agent wrapping the nitrogen-doped carbon nanotube. In preparation of the precursor, a self-assembled body can be formed through the electrostatic interaction and the hydrogen-bond interaction by means of nitrate radicals and melamine under the acid condition, cobalt ions are adsorbed into the self-assembled body, ordered arrangement and assembly of materials in the high-temperature baking process are facilitated by the pre-assembled precursor, and therefore more catalysis active sites are exposed, and the improvement of the performance of a catalyst is facilitated.

Process for the treatment of a lateritic nickel / cobalt ore consisting of a mixture (2) of limonite and saprolite, characterized in that: the mixture (2) in the presence of an iron-precipitating agent is made into a pulp (1), having a solids content of between 10 and 40% by weight; the pulp undergoes a leaching operation (4) with sulphuric acid (5), at a temperature between 70 DEG C and the boiling point and at atmospheric pressure; and a solid-liquid separation (8) is carried out so as to obtain an iron-containing solid residue (9) and a solution containing nickel and cobalt ions. Process for producing nickel and / or cobalt intermediate concentrates or commercial products using the above process.

The invention discloses a cyanide-free zinc dipping solution and a cyanide-free electroplating method of filter aluminium alloy by using the cyanide-free zinc dipping solution. The cyanide-free zinc dipping solution, measured as per liter of cyanide-free zinc dipping solution, comprises 450-600 ml of plating bath solution and 400-550 ml of water, wherein the plating bath solution comprises 20-40 g / L zinc ions, 2-10 g / L nickel ions, 0.001-0.400 g / L copper ions, 0.05-1.00 g / L iron ions, 1-4 g / L cobalt ions, 80-200 g / L alkali metal hydroxide, 50-100 g / L main complexing agent, 13-40 g / L auxiliary complexing agent, and 0.07-2.00 g / L crystallization refiner. Zinc dipping and electroplating on materials with high silica content can be carried out by using the cyanide-free zinc dipping solution by just conducting zinc dipping once, the operation is simple, and the control is easy.

The invention relates to a method for preparing magnetic silicon dioxide microspheres with the surfaces chelated with metal ions; the method of the inventioncomprises the following steps of preparation of the magnetic silicon dioxide microspheres, epoxidation of the magnetic silicon dioxide microspheres, carboxylation of the magnetic silicon dioxide microspheres and chelation technique of metal ions. Compared with the existing preparing method, the method of the invention has the advantages of reasonable design, simple operation and large amount of chelation of metal, etc. The magnetic silicon dioxide microspheres with the surfaces chelated with the metal ions, which are prepared by adopting the method, contain cobalt ions, have stronger bonding force with the modified microspheres so as to lead the cobalt ions to be not easy to leak out, and have higher selectivity and proper bonding strength with histidine on the protein, thus leading the magnetic silicon dioxide microspheres with the surfaces chelated with the metal ions to have high selectivity to hexameric histidine tag protein, and being easy to realize the separation and the purification of the target protein; the magnetic silicon dioxide microspheres with the surfaces chelated with the metal ions, which are prepared by adopting the method, can be used for separating the hexameric histidine tag protein.

The invention discloses a method for degrading organic waste water by activating persulfate through manganese-cobalt composite oxide. The method includes the following steps that under the normal temperature condition, the persulfate with the concentration of 0.5-5.0 mM and the manganese-cobalt composite oxide with the concentration of 0.1-2.0 g / L are added into the waste water containing organic pollutants, the water sample is treated for 20 min-3 h, then solid-liquid separation is carried out, and the treatment process is completed. The heterogeneous manganese-cobalt oxide is adopted as a catalyst and can efficiently and continuously activate the persulfate to generate sulfate free radicals and hydroxyl free radicals to degrade the organic pollutants. Serving as an environment-friendly material, the manganese oxide can effectively reduce leakage of cobalt ions and reduce secondary pollution and biotoxicity. The method is suitable for treatment on various kinds of organic waste water, high in efficiency and persistence, capable of being used repeatedly and convenient to operate and provides wide prospects for treatment on the degradation-resistant organic waste water.

The invention discloses a one-dimensional NiCo2S4 crystal array on the surface of an activated carbon fiber and a preparation method of the one-dimensional NiCo2S4 crystal array. The preparation method comprises the following steps: dissolving soluble nickel salt and soluble cobalt salt in water, wherein the mole number ratio of nickel ions to cobalt ions is 1:2; adding ethylene diamine tetraacetic acid of which the mole number is equal to one half of the total mole number of nickel and cobalt ions and thiourea of which the mole number is equal to 5-10 times of the total mole number of nickel and cobalt ions; immersing an activated carbon fiber in the solution and soaking; then carrying out hydrothermal treatment at the temperature range of 150-260 DEG C; washing hydrothermally treated activated carbon fiber and drying to obtain the one-dimensional NiCo2S4 crystal array growing on the surface of activated carbon fiber. Since the one-dimensional NiCo2S4 crystal array on the surface of the activated carbon fiber obtained by the invention has the directional growth structure, the specific surface area of the activated carbon fiber can be improved, and the one-dimensional NiCo2S4 crystal array is conducive to electronic transport and is an ideal catalyst material and electrode material.

The embodiment of the invention discloses a preparation method of a carbon-coated nickel-cobalt lithium manganate positive electrode material, and belongs to the technical field of preparation of a lithium battery positive electrode material. The preparation method comprises the following steps: adding a chelating agent and a carbon source into a solution containing lithium salt, nickel salt, cobalt salt and manganese salt, and performing high-temperature spray pyrolysis to obtain precursor powder; compacting the precursor powder by vibration or pressure, wherein the compaction density by the vibration or the pressure is 0.3-3.2g / cm<3> so that lithium ions, nickel ions, cobalt ions and manganese ions are uniformly dispersed in the powder and are contacted closely; and calcining the precursor powder, and cooling to obtain the carbon-coated nickel-cobalt lithium manganate positive electrode material with the good conductivity and the high cyclic stability. The carbon-coated nickel-cobalt lithium manganate positive electrode material comprises nickel-cobalt lithium manganate and carbon coating the surface of nickel-cobalt lithium manganate. The method disclosed by the embodiment of the invention is easy to operate and easy to control and facilitates the large-scale industrial production.

The invention provides a cobaltosic oxide multi-shell hollow sphere cathode material for a lithium ion battery and a preparation method thereof. The method comprises the steps of: taking a carbon sphere prepared by a hydrothermal method as a template; controlling the quantity of cobalt ions in the carbon sphere and the entering depth thereof by controlling the ratio of water to ethanol in a cobalt salt solution, the temperature of the solution and the adsorption capacity of the carbon sphere; and preparing single-shell, dual-shell, tri-shell and four-shell cobaltosic oxide hollow spheres. The lithium ion battery of taking the cobaltosic oxide multi-shell hollow sphere as a cathode has large specific surface area and a plurality of lithium ion storage sites; the specific capacitance is improved; meanwhile, the appropriate multi-shell cavity structure not only can adjust the electrode structure and volume change, but also can effectively reduce the transmission distance between the lithium ion and electrons. Thus, the cycling performance and rapid charge and discharge capacity are obviously improved. The method disclosed by the invention is convenient and concise to operate, and high in controllability, and has a wide application prospect; and the performance of the lithium ion battery can be obviously improved.

The invention relates to a chemical cleaning method of a reverse osmosis membrane. In the method, aiming at a reverse osmosis membrane for processing PTA refining wastewater, inorganic pollutants which are formed by cobalt ions, manganese ions, hydroxide thereof and the like and are deposited and adsorbed on the surface of the membrane are dissolved and eluted by using acid rinse prepared by citric acid and sodium bisulfite; organic colloid pollutants deposited and adsorbed on the surface of the membrane are dissolved and eluted by using alkaline rinse containing sodium dodecyl benzene sulfonate and sodium hydroxide. The method can elute the pollutants on the surface effectively, restore operating flux, operating pressure and desalination rate of the reverse osmosis membrane, and ensure that the process of processing the reverse osmosis membrane for the PTA refining wastewater is stable in operation.

The invention relates to a preparation method of a cobalt phosphide hollow nano-fiber material.The preparation method comprises the steps of adding cobalt salt to N, N-dimethylformamide, after the cobalt salt is dissolved, adding polyvinylpyrrolidone, conducting stirring, so that a precursor spinning solution is obtained, and conducting electrostatic spinning, so that a polyvinylpyrrolidone nanofiber membrane doped with cobalt ions is obtained; conducting pre-oxidation, and then conducting calcination at the temperature of 400-700 DEG C, so that a hollow tubular cobaltosic oxide nano-fiber is obtained; then mixing the hollow tubular cobaltosic oxide nano-fiber with sodium hypophosphite monohydrate, conducting a phosphorization reaction, and conducting cleaning and drying, so that the cobalt phosphide hollow nano-fiber material is obtained.The method is environmentally friendly in process and low in cost; the obtained cobalt phosphide hollow nano-fiber material is stable in chemical property and high in activity of electro-catalysis hydrogen evolution and expected to serve as an ideal high-performance electrochemical hydrogen evolution catalytic material.

It is an object of the present invention to provide a chemical conversion coating agent which places a less burden on the environment and can apply good chemical conversion treatment to all metals such as iron, zinc and aluminum. A chemical conversion coating agent comprising: at least one kind selected from the group consisting of zirconium, titanium and hafnium; fluorine; and an adhesion and corrosion resistance imparting agent, wherein said adhesion and corrosion resistance imparting agent is at least one kind selected from the group consisting of: 1 to 5000 ppm (metal ion concentration) of at least one kind of metal ion (A) selected from the group consisting of zinc ion, manganese ion and cobalt ion; 1 to 5000 ppm (metal ion concentration) of alkaline earth metal ion (B); 1 to 5000 ppm (metal ion concentration) of metal ion (C) of Group III in the periodic table; 0.5 to 100 ppm (metal ion concentration) of copper ion (D); and 1 to 5000 ppm (as a silicon component) of a silicon-containing compound (E).

The invention belongs to the technical field of material preparation, and particularly relates to a synthesis method for low-temperature manganese-based compound metal oxide denitration catalysts. According to the method, a manganese salt and a salt from a cobalt salt, a ferric salt or a nickel salt are dissolved in ethylene glycol in a mixed manner; a sodium carbonate water solution is dripped at a low temperature, and coprecipitation is carried out; and coprecipitation products are washed by water, are dried, and are calcined in the air, and products can be obtained. The synthesis method provided by the invention adopts a low-temperature artificially induced crystal splitting technology, one kind of ions from cobalt ions, ferric ions and nickel ions are added, and manganese ion precipitate crystals are induced to split in the manganese ion precipitate crystal growth process. The split crystals do not agglomerate during the growing in low-temperature environment. After the crystals after splitting growth are calcined, manganese-based compound metal oxides with high specific surface area can be obtained, and the manganese-based compound metal oxides can show excellent low-temperature catalytic activity when being used for catalyzing a denitration reaction. The synthesis method has the advantages that the operation is simple, the control is easy, and raw materials can be easily obtained, so the synthesis method is suitable for large-scale production, and in addition, the environment pollution is little.

The invention provides a method for recovering waste hard alloy. According to the method, the waste hard alloy is used as an anode to directly perform electrolysis in a fused salt. The method comprises the following steps: 1) carrying out vacuum dehydration by using a fused salt dielectric; 2) by using the waste hard alloy as the anode and an inert electrode as the cathode, electrolyzing in the molten fused salt dielectric at 350-1000 DEG C; and 3) separating and collecting the metal powder and fused salt dielectric after electrolysis. According to the technical scheme, tungsten and cobalt ions can be directly dissolved out of the anode material-waste hard alloy to enter the fused salt dielectric, and deposit on the cathode plate under the driving action of the electrolysis voltage, thereby obtaining the metal powder granules. The tungsten, cobalt and other product materials obtained by electrolysis can be used as hard alloy materials, high-temperature structure materials, weapon materials, photocatalytic materials and the like, and are applicable to the fields of production processing, aerospace, war industry, environmental energy sources and the like. The method has the advantages of short technical process, no discharge of solid / liquid / gas waste and environment friendliness.

The invention discloses a preparation method for carbon nano tube surface loaded magnetic alloy nano particle composite material, which belongs to the field of electromagnetic wave absorbing material preparation. The preparation method comprises the following steps: after purifying and activating a carbon nano tube, evenly dispersing the carbon nano tube to chloride salt solution of iron, cobalt and nickel, slowing adding an alkali solution dropwise into the solution in the fierce agitation process, and regulating the pH value of the solution and making iron ions, cobalt ions and nickel ions be coprecipitated onto the surface of the carbon nano pipe in the form of hydroxide according to the alloy proportion set when the solution is prepared; taking out a deposit by centrifugation or filtering; and after drying the deposit, carrying out the heat treatment of the deposit in the reducing atmosphere to obtain the carbon nano tube composite material loaded with magnetic alloy particles. The preparation method adopts a simple process. As no impurity element is introduced into the preparation process, the obtained magnetic alloy particles have high degree of crystallinity and excellent magnetic properties. In addition, the method has easy regulation of the alloy components. The composite material prepared by the method is significantly applied in the fields of electromagnetic interference resistance, stealth, microwave darkrooms, and the like.

The invention discloses a cobalt-nitrogen-sulfur co-doped carbon aerogel di-functional oxygen catalyst and a preparation method and application thereof. The method comprises the following steps: uniformly combining cobalt ions with sodium alginate; performing hydrothermal treatment together with dopamine and mercaptan; centrifuging to obtain dopamine / mercaptan / cobalt-sodium alginate hydrogel; performing high-temperature calcination on the dopamine / mercaptan / cobalt-sodium alginate hydrogel obtained after freeze drying to obtain the cobalt-nitrogen-sulfur co-doped carbon aerogel di-functional oxygen catalyst. The catalyst is an aerogel porous material with an average aperture of 2 to 4 nanometers and a specific surface area of 126.8 to 138.3m<2> / g; cobalt exists in the form of a Co simple substance, CoO and Co3O4; a nitrogen atom doped in a porous carbon material mainly exists in the form of pyrrole and graphite. The cobalt, nitrogen and sulfur are co-doped, so that the catalyst has high oxygen evolution and oxygen reduction catalytic activities at the same time under an alkaline condition; moreover, the catalyst has the advantages of adoption of low-cost raw materials, simple preparation method, easiness in operation and convenience for large-scale production.

The invention discloses a metal organic skeleton material for removing cobalt ions from wastewater and a preparation method of the metal organic skeleton material. The method comprises the following steps: preparing UiO-66-NH2 firstly, then preparing UiO-66-R1, and finally, preparing a bis-Schiff base functional group-containing metal organic skeleton material; and then using the bis-Schiff base functional group-containing metal organic skeleton material for adsorption treatment on the cobalt ions in the wastewater, namely, carrying out adsorption treatment on the cobalt-containing wastewater, and inspecting influences of factors, including cobalt-containing solutions with different pH values, different adsorption temperatures, different adsorption time and different original cobalt ion concentrations on cobalt ion adsorption with UiO-66-Schiff base as an adsorbent, wherein the adsorbing capability of the adsorbent to the cobalt ions under a preferred condition can reach 256mg / g. The preparation method of the invention has the characteristics of simpleness in technology, no secondary pollution and high adsorbing capability; the metal organic skeleton material has the characteristics of capability of cyclic utilization, resource conservation, cost reduction and the like; and a new method for removing the cobalt ions from the cobalt-containing wastewater is found.

The invention discloses a nitrogen and cobalt double-doped porous carbon composite bifunctional oxygen catalyst and a preparation method and application thereof. The preparation method comprises the steps that firstly, under a hydrothermal condition, divalent cobalt ions, melamine and sodium alginate are compounded to obtain melamine / cobalt ion-sodium alginate; and secondly, high-temperature calcination is performed, and then the nitrogen-cobalt double-doped porous carbon bifunctional oxygen catalyst is prepared. The catalyst is made of a porous material, the average hole diameter of the catalyst is 2 nm-8 nm, and the specific area is 148.23 m<2> / g-188.27 m<2> / g. According to the catalyst, cobalt exists in the forms of the Co elementary substance, CoO and Co3O4; and nitrogen atoms doped inthe porous carbon material exist in the forms of pyrrole and pyridine. Due to double doping of the cobalt and nitrogen, the catalyst has high oxygen evolution and oxygen reduction catalytic activity,good stability and excellent methyl alcohol tolerance at the same timeunder alkaline conditions, used raw materials are low in cost, the preparation method is simple, operation is easy, and large-scale production is convenient.

Usage ratio of cobalt ion in material of positive pole is only 50% currently. The treating method disclosed in the invention includes following steps: coating a layer of metallic oxide film on surface of LiCoO2 granules; carrying out drying and sintering treatment. Features of the product produced from the method are: improving high temperature property, cyclical stability, stability of anti overcharge; postponing ascend of internal resistance in charging procedure. The battery is posible to be charged at higher voltage. The method raises weight of material and volume energy density more than 20%.

Belonging to the technical field of photoelectric phosphorescence materials, the invention discloses a preparation method of an iridium complex-containing phosphorescence material and its application in cobalt ion detection. With a general structural formula as shown in formula I, the iridium complex-containing phosphorescence material of the invention can be used for Co<2+> detection and comprises a main ligand and an auxiliary ligand, wherein, the main ligand is a derivative of 3, 4-disubstituted cinnoline, and the auxiliary ligand is a derivative of 15 crown-5 ether dipyridine. By means of the influence of Co<2+> on photo-physical and sensing properties of the iridium complex, the phosphorescence chemical sensor can observe the change of its phosphorescence emission spectrum so as to reach the Co<2+> detection purpose. The phosphorescence chemical sensor of the invention has the advantages of rapid phosphorescence response speed, easy differentiation from a fluorescence background, large range, high identification sensitivity to Co<2+>, good stability, and applicability for Co<2+> detection in various environments, and small interference from other positive ions, etc. Formula I is shown as the following.

The invention discloses a method for processing dye waste water based on activation of peroxymonosufate by three-dimensional ordered mesoporous CoFe2O4 and aims to solve the problem of low catalysis efficiency of present spinel CoFe2O4 to peroxymonosufate. The method is implemented through the following steps: firstly, three-dimensional ordered mesoporous CoFe2O4 is prepared; secondly, dye waste water with an appointed concentration is prepared, and the prepared solution is placed in a brown shake flask; thirdly, peroxymonosufate is added; fourthly, the three-dimensional ordered mesoporous CoFe2O4 is added; fifthly, the three-dimensional ordered mesoporous CoFe2O4 is separated by utilization of an applied magnetic field, and processing of dye in waste water based on activation of peroxymonosufate by three-dimensional ordered mesoporous CoFe2O4 can be completed. High-efficiency processing of dye waste water can be achieved by utilization of three-dimensional ordered mesoporous CoFe2O4 in cooperation with the peroxymonosufate technology, and the removal rate exceeds 90%. The cobalt ion leaching rate is low during the usage process, and environment pollution is reduced. The catalyst can be separated rapidly through an applied magnetic field and can be recycled, and the operation cost is lowered.

The present invention provides a method of producing a porous carbon material in which a soft carbon-type carbon material is activated with alkali in the presence of a carboxylic acid ion and at least one metal ion selected from the group consisting of iron ions, cobalt ions, manganese ions and nickel ions. The method is capable of industrially producing a porous carbon material having a specific surface area per unit volume of 1000 (m2 / cm3) or more in high yield and at low cost. The packing density of the porous carbon material can also be increased, and a high capacitance per unit volume can be obtained when the porous carbon material is used as a polarizable electrode material. Therefore, the present invention also provides an electrical double layer capacitor having a small size and a large capacitance, and using the porous carbon material as a polarizable electrode.

The invention relates to a method for electrodepositing a nanocrystalline nickel-cobalt alloy by double-pulse. The method for electrodepositing the nanocrystalline nickel-cobalt alloy by double-pulse is characterized by comprising the following processing steps: in a plating solution with a pH value of 5-6, a nickel ion concentration of 0.68-0.95 mol / L and a cobalt ion concentration of 1.9*10<-2>to 3.8*10<-2> mol / L, taking a soluble nickel plate after the soluble nickel plate is subjected to surface treating as a anode, taking an iron sheet after the iron sheet is subjected to surface treating as a cathode and electroplating a nanocrystalline nickel-cobalt alloy layer by using double-pulse electrodepositing technology, wherein the time for electrodepositing is 15-20 min, the positive-going pulse current density is 1.0-2.0 A / dm<2>, the positive-going duty ratio is 60-80%, the working time of the positive-going pulse is 50-100 ms and the positive-going cycle is 40-60 ms; and the negative-going pulse current density is 0.1-0.2 A / dm<2>, the negative-going duty ratio is 60-80%, the working time of the negative-going pulse is 10-20 ms, the negative-going cycle is 1-2 ms and the workingtime of the positive-going pulse is 5-10 times of that of the negative-going pulse. The nickel-cobalt alloy coating prepared by the method has the advantages of smooth surface, compact structure, fine and even crystal, good smoothness, no crack and excellent corrosion resistance.

The invention provides a preparation method of a Ni-Co-Mn ternary precursor. The preparation method comprises the steps of (1) preparing a mixed salt solution containing a nickel salt, a cobalt salt and a manganese salt according to a proportion that the mole ratio of nickel ions, cobalt ions and manganese ions is 1:1:1, adding an oxidizing agent into the mixed salt solution, and obtaining a mixed solution after uniform stirring, wherein the mass of the oxidizing agent accounts for 0.1-10% of the total mass of the nickel ions, the cobalt ions and the manganese ions in the mixed salt solution; (2) combining and adding the mixed solution, an alkali liquid and an ammonia solution into a reaction kettle, and performing reaction for 15-26 hours under 40-80 DEG C to generate paste containing the Ni-Co-Mn ternary precursor; and (3) allowing the paste containing the Ni-Co-Mn ternary precursor to overflow out of the reaction kettle after reaction finishes, and obtaining the Ni-Co-Mn ternary precursor after solid-liquid separation, washing and drying. The oxidizing agent is added into the mixed salt solution, so that a part of divalent manganese ions are oxidized to trivalent manganese ions, the formation of a crystal nucleus is facilitated, the primary crystal gain of a spherical precursor is refined, and the specific area of the precursor is expanded.

The invention relates to a preparation method of monodisperse cobalt-nitrogen co-doped hollow carbon nano-particles. The method comprises the following steps: adding cobalt ions in ZnO nanosphere template and Zn source to form a double-metal hybrid zeolite imidazate skeleton compound shell, namely the ZnO@Zn / Co-ZIF precursor; and then performing high-temperature carbonization on the ZnO@Zn / Co-ZIF precursor to directly obtain the cobalt-nitrogen co-doped hollow carbon nano-particles with the specific surface area as 400-600m<2>g-1. By use of the preparation method disclosed by the invention, the synthesis method is simple, the operation of removing a nuclear layer template by use of acid-pickling is unnecessary, and the environment-friendly preparation process can be realized.

The invention discloses a nano-copper-cobalt bimetallic catalyst as well as a preparation method and an application thereof. The catalyst takes SiO2, ZrO2, CeO2 or Al2O3 as a carrier and La2O3 as an aid, and is loaded with an active ingredient Cu[x]Co[1-x]. The preparation method comprises the following steps: soaking a mixed solution of lanthanum ions, copper ions, cobalt ions, citric acid and a chelating agent in the SiO2, ZrO2, CeO2 or Al2O3 carrier, drying and roasting to obtain a catalyst precursor; reducing the precursor through H2, CO or CH4 reducing gas or mixed gas containing the H2, CO or CH4 reducing gas and inert gas to obtain the loaded copper-cobalt bimetallic catalyst taking lanthanum oxide as the aid. The preparation method has the advantages that the interaction among Cu, Co and the lanthanum oxide is facilitated in the process of obtaining the catalyst through the precursor, and the components such as the Cu, the Co and the lanthanum oxide are high in dispersity and good in stability. The catalyst is used in reaction for preparing low-carbon alcohol from synthetic gas, and is relatively high in selectivity, activity and stability on alcohols each with 2-6 carbon atoms.

It is an object of the present invention to provide a processing solution used for forming a hexavalent chromium free, black conversion film, which is applied onto the surface of zinc or zinc alloy plating layers, and which has corrosion resistance identical to or higher than that achieved by the conventional hexavalent chromium-containing conversion film. <??>According to an aspect of the present invention, there is provided a processing solution for forming a hexavalent chromium free, black conversion film on zinc or zinc alloy plating layers, the processing solution comprising: nitrate ions and trivalent chromium in a mole ratio (NO<3-> / Cr<3+>) of less than 0.5 / 1, wherein the trivalent chromium is present in the form of a water-soluble complex with a chelating agent; and cobalt ions and / or nickel ions, wherein the cobalt ions and / or nickel ions are stably present in the processing solution without causing any precipitation by forming a hardly soluble metal salt with the chelating agent; wherein the solution reacts with zinc when it is brought into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, black conversion film containing zinc, chromium, cobalt and / or nickel, and the chelating agent on the plating.