114 results about "Vanadate" patented technology

The invention discloses a silver vanadate photocatalytic material, a preparation method thereof and an illuminating lamp. The preparation method comprises the following steps: firstly, respectively dissolving NH4VO3 and AgNO3 in deionized water, uniformly mixing by magnetic stirring, adjusting the pH value of the solution, and then carrying out hydrothermal synthesis reaction to obtain the Ag3VO4 photocatalytic material. The Ag3VO4 photocatalytic material with controllable morphology, uniform particle size and good dispersity is prepared by adopting a synthesis strategy of a one-step hydrothermal method, the performance of the photocatalyst is optimized by regulating and controlling the pH value, the raw materials and the process are simple, the conditions are easy to control, the cost is low, the photocatalytic degradation rate of the catalyst to organic pollutants is high, and the method is suitable for industrial production. The stability of a crystal structure and catalytic activity can be kept under long-term illumination, and the functional application of a photocatalytic air purification technology can be realized by integrating with an illumination lamp.

A process produces high-purity vanadium chemicals from vanadium raw materials having high molybdenum contents. Molybdenum is selectively precipitated via vanadium from alkaline vanadate solutions using the following process steps: providing a molybdenum-containing alkaline vanadate solution, adding calcium hydroxide as a precipitant in portions while keeping the pH constant between 6 and 7 using acid, mixing the solution, solid-liquid separation of the resulting suspension, and further processing the low-molybdenum alkaline vanadate solution to produce a high-purity vanadium chemical having a molybdenum content of at most 500 ppm.

The invention discloses a vanadium iron-site doped iron phosphate material and a preparation method, and relates to the technical field of lithium ion battery positive electrode material preparation, pure water is used as a base solution, and a vanadium salt solution with the pH value of 2.0-3.0, a ferrite solution with the pH value of 1.0-2.5 and a phosphorus-oxygen mixed solution with the pH value of 5.0-7.0 are simultaneously added into a reaction kettle in a three-strand parallel flow mode for a co-precipitation reaction. By controlling the acid environment of a key solution system, reduction of metavanadate radicals or generation of ferric vanadate precipitates is effectively inhibited, and vanadium elements are successfully and uniformly doped to iron sites of iron phosphate crystal lattices; the mass ratio of iron to phosphorus in the obtained iron phosphate material is stabilized at 95-98%, the doping amount of vanadium is 100-10000 ppm, and the vanadium is uniformly distributed. Lithium iron phosphate prepared by taking the material as a precursor has higher discharge capacity and compaction density, and the electrochemical performance of a lithium ion battery is remarkably improved.

The invention belongs to the field of vanadium batteries, and particularly discloses a vanadium battery key material as well as a preparation method and a preparation system thereof. The method comprises the following steps: adding ammonium salt and acid into an alkaline vanadium-containing leaching solution, and carrying out weak acid ammonium salt vanadium precipitation reaction under the conditions that the pH is 4-6 and the temperature is 20-85 DEG C to obtain a sodium ammonium decavanadate solid; the method comprises the following steps: mixing a sodium ammonium decavanadate solid with a solution containing ammonium ions, and carrying out solid-phase crystal transformation ammonium sodium replacement reaction at the temperature of 90-100 DEG C to obtain high-purity ammonium vanadate; directly calcining the high-purity ammonium vanadate or calcining the high-purity ammonium vanadate after re-dissolution recrystallization to obtain high-purity vanadium pentoxide; the high-purity vanadium pentoxide is used for preparing a vanadium battery key material. According to the scheme, the alkaline vanadium-containing leachate serves as the raw material, deep removal of impurities is achieved through weak acid ammonium salt vanadium precipitation and solid-phase crystal transformation ammonium sodium replacement, high-purity ammonium vanadate is prepared, high-purity vanadium pentoxide is further prepared, and the high-performance vanadium battery key material is prepared with the high-purity vanadium pentoxide serving as the raw material.

The invention relates to the technical field of hydrometallurgy, and provides a method for cleanly extracting vanadium from vanadium slag based on dolomite. According to the method, dolomite is adopted to replace a traditional calcification or sodium salt roasting auxiliary agent to co-roast the vanadium slag, and vanadium in the vanadium slag is roasted through two-step temperature control to be converted into acid-soluble calcium magnesium vanadate roasting clinker. The roasting clinker is subjected to acid leaching to obtain vanadium liquid, the vanadium liquid is subjected to deep impurity removal through a magnesium ammonium phosphate precipitation method, ammonium sulfate is added into the vanadium liquid, the pH value is adjusted, acid ammonium salt vanadium precipitation is conducted, and ammonium polyvanadate is obtained. And washing, filtering, drying and calcining the ammonium polyvanadate to obtain high-purity powder vanadium pentoxide or melting and casting to obtain high-purity tablet vanadium pentoxide. Vanadium precipitation wastewater is subjected to reduction treatment, lime neutralization and solid-liquid separation and then is reused in a leaching system, and cyclic utilization of ammonium salt and water resources is achieved. By means of the technical scheme, the problem that in the related technology, the vanadium leaching rate is low is solved.

This invention provides a method for in-situ removal of vanadium from wastewater. The method involves first adjusting the pH to acidity and then alkalinity, thereby controlling the degree of vanadium hydrolysis and disrupting the stable form of (meta)vanadate in the wastewater, causing it to primarily exist as VO2(OH)2. ‑ Vanadium exists in the form of vanadium, and when Fe(II) is added, it undergoes a redox reaction with V(V) in the wastewater, effectively reducing vanadium(V) in the wastewater to V, which has lower toxicity and is relatively unstable. 2+ (VI) Reduce wastewater toxicity; then adjust to an alkaline environment, utilizing the interaction of hydroxide ions, iron, and vanadium to precipitate vanadium into VO2·H2O and Fe2O3·V2O5·H2O, thus achieving vanadium removal. The entire process of this invention is easy to control, has a high vanadium removal rate, and requires a small amount of reducing agent.

The invention discloses an L-cysteine doped ammonium vanadate positive electrode material, a preparation method thereof and application of the L-cysteine doped ammonium vanadate positive electrode material in an aqueous zinc ion battery, and belongs to the technical field of materials. The preparation method comprises the following steps: adding ammonium metavanadate and oxalic acid into deionized water, stirring and mixing, then adding L-cysteine, carrying out hydrothermal reaction on the obtained mixed solution, cooling to room temperature, carrying out centrifugal cleaning, and carrying out vacuum drying to obtain the L-NVO. L-NVO is prepared through a simple one-step hydrothermal method, L-cysteine is doped into the electrode material through further reaction, the introduction of L-cysteine not only enlarges the interlayer spacing of NVO, but also participates in the storage of zinc ions, increases the active sites of the zinc ions, effectively promotes the diffusion of ions and charge transfer, and improves the electrochemical performance of the electrode material. The conductivity of the material is improved, the internal resistance of the material is reduced, and the structural flexibility and stability of the material are maintained, so that the overall performance of the aqueous zinc ion battery is improved.

The present application belongs to the technical field of inorganic chemical industry, and particularly relates to a method for preparing manganese vanadate from vanadium pentoxide. The method for preparing manganese vanadate from vanadium pentoxide is original, and the method for preparing manganese vanadate by roasting vanadium pentoxide in an inert gas atmosphere is used. Vanadium pentoxide powder is mixed with manganese carbonate (or manganese oxide) reagent to obtain manganese vanadate. As one of ternary vanadates, manganese vanadate has good electrochemical performance and optical performance, and can be applied in batteries and photoelectric materials. The method has great significance for the study of vanadium slag leaching mechanism and the development of subsequent products.

The invention discloses a method for comprehensively utilizing vanadium and chromium resources, which comprises the following steps: mixing chromium hydroxide with sodium hydroxide, and introducing oxygen for liquid-phase oxidation to obtain an oxidation solution; adding calcium oxide into the oxidation liquid, stirring and mixing, and performing solid-liquid separation after reaction to obtain calcium vanadate solid and vanadium-free alkali liquid; adding a decalcifying agent into the vanadium-free alkali liquor, and carrying out solid-liquid separation to obtain calcium carbonate and refined sodium chromate alkali liquor; reacting calcium vanadate with roasting slurry containing aluminum, silicon and carbonate to form calcium aluminosilicate precipitate and desiliconized high-vanadium alkali liquor; continuously neutralizing the desiliconized high-vanadium alkali liquor and the carbonization solution to obtain an aluminum-vanadium high-valued product and a neutral solution; the neutral liquid is carbonized, and obtained sodium bicarbonate and carbonized liquid can be returned to a system for recycling. The method for comprehensively utilizing the vanadium and chromium resources has the advantages of being simple in process, environmentally friendly, efficient, easy to control in operation, easy to obtain raw materials, low in production cost and the like.

The invention discloses a method for directly preparing ferrovanadium by taking ammonium vanadate as a raw material. The method comprises the steps of raw material pretreatment, vacuum heating decomposition, furnace charge mixing and aluminothermic reduction smelting. In the step of vacuum heating decomposition, the pretreated ammonium vanadate is loaded into a double-cone rotary vacuum dryer to be subjected to vacuum heating, so that the pretreated ammonium vanadate is decomposed, ammonia gas and water vapor are released, and a decomposition product with V2O4 and V2O5 as main components is obtained; the step of mixing the furnace charge comprises the following steps: uniformly mixing a decomposition product with aluminum powder, lime, iron powder and a cold charge according to the mass ratio of (60-120): (30-65): (6-10): (6-10): (6-15) based on the mass of V2O5; in the aluminothermic reduction smelting, a magnesium rod is used for igniting furnace charge to carry out aluminothermic reaction; and after the reaction is finished, cooling to room temperature to obtain the ferrovanadium alloy. The method can effectively simplify the process flow, reduce the production cost, improve the product quality, and solve the technical problems of tedious steps and high cost of the traditional process.

The invention discloses a titanium white waste acid treatment process, and relates to the technical field of industrial waste regeneration. The titanium white waste acid is subjected to microfiltration and membrane electrolysis treatment, sulfuric acid is separated and recycled under the control of constant pressure and constant current, and residual liquid is subjected to electrodialysis treatment to oxidize ferrous ions into ferric hydroxide precipitates and calcined into ferric oxide; carrying out reduction leaching on the titanium-containing material, hydrolyzing to generate metatitanic acid, and calcining to obtain titanium dioxide; oxidizing the hydrolysate to precipitate vanadate, and calcining to obtain vanadium pentoxide; adjusting the pH value of the filtrate, selectively adsorbing scandium through a biological adsorption column, precipitating and calcining the eluent to obtain scandium oxide, and regenerating and recycling the adsorbent through acid pickling. According to the process, through multi-stage treatment and biological adsorption, resource recycling of sulfuric acid, iron, titanium, vanadium and scandium components in the waste acid is achieved, the process is clean and efficient, secondary pollution of a traditional process is avoided, and a green low-carbon solution is provided for waste acid treatment in the titanium dioxide industry.

The invention discloses a preparation method and application of a vanadium-doped titanium dioxide composite material, and relates to the technical field of titanium dioxide composites.The preparation method comprises the following steps that 1, ammonium vanadate and titanium dioxide are mixed in proportion, the doping amount of the vanadium element is controlled to range from 0.1 wt% to 12.5 wt% according to the total mass of the mixture, then high-temperature heating is conducted, and a mixture is obtained; vanadium-doped titanium dioxide powder is obtained; and (2) mixing the vanadium-doped titanium dioxide powder with a carrier in proportion, controlling the content of the vanadium-doped titanium dioxide powder to be 10-30 wt% based on the total mass of the composite material, and carrying out physical grinding to obtain the powdery vanadium-doped titanium dioxide composite material. The catalytic material disclosed by the invention is applied to degradation of sulfur hexafluoride and has excellent degradation capability.

This invention relates to the field of nanomaterials technology, and discloses a vanadate composite material, its preparation method, and its application. A reaction solution containing a surfactant is prepared to generate bubbles. These bubbles then act as soft templates under rapid stirring and heating. Vanadium oxide is dispersed in this reaction solution and reacted at a specific temperature for a certain time, allowing the surfactant to intercalate the vanadium oxide, transforming it into vanadate. The surfactant then coats the outer surface of the vanadate, resulting in an in-situ surface-modified vanadate composite material. The surfactant layer of this composite material can regulate the reaction layer between the electrode surface and the electrolyte, preventing electrode material dissolution or structural collapse during the electrochemical reaction process, thus significantly improving the performance of electrochemical energy storage devices. The foaming effect of the surfactant ensures that the bubbles are uniformly dispersed in the liquid, acting as soft templates for the attachment and growth of vanadate crystals.

The application provides a method for preparing vanadium electrolyte by crystallizing vanadium slag with bayer seed mother liquor, which comprises the following steps: reducing and acid leaching the bayer seed mother liquor crystallized vanadium slag, converting V(V) and As(V) into V(IV) and As(III), adding arsenic removal precipitator to remove arsenic, and further hydrolyzing VO(OH)2; converting the VO(OH)2 into pentavalent vanadate solution through oxidation and alkali leaching, and further removing impurity ions such as arsenic, phosphorus, aluminum and silicon through multiple crystallization to obtain high-purity vanadate; finally, converting the high-purity vanadate into V(IV) solution through reduction and acid leaching, adding arsenic removal precipitator again to realize deep arsenic removal, hydrolyzing to obtain VO(OH)2, and preparing VOSO4 electrolyte through sulfuric acid acid solution.

The present application belongs to the field of waste resource utilization and hydrometallurgy, and particularly relates to a method for preparing vanadium pentoxide by using organic amine flue gas desulfurization residue, which adopts melamine method flue gas desulfurization residue as a vanadium precipitation agent. Under acidic conditions, the organic amine flue gas desulfurization residue can react with vanadate to generate more stable organic amine vanadate precipitate. After filtration, the precipitate is high-temperature calcined to obtain high-purity powder vanadium pentoxide. Compared with the current ammonium sulfate salt vanadium precipitation method, the present application has higher precipitable vanadium concentration, low ammonia nitrogen concentration in wastewater, and no need for heating in the reaction process, and is an environmentally friendly and low-cost vanadium pentoxide preparation technology.

The application discloses a preparation method and application of a nickel vanadate / carbon nanotube composite nanosphere. NiCl2.6H2O and nickel-plated carbon nanotubes are added into an ammonium metavanadate solution, and then anhydrous ethanol is slowly added. The mixture is heated at a temperature of 160-200 DEG C for 6-10 hours. The mixture is centrifuged and the precipitate is dried to obtain the nickel vanadate / carbon nanotube composite nanosphere. The nickel vanadate / carbon nanotube composite nanosphere is synthesized by a one-step hydrothermal method for the first time, and has high dispersion and uniform particle size. The unique CNT winding main body structure can provide an electrically conductive path for electron transmission. The ultra-small nickel vanadate nanoparticles are uniformly embedded on the CNT, which accelerates electron transmission and greatly reduces the transmission distance of lithium ions, and improves the electrochemical performance of the nickel vanadate / CNT composite nanosphere. The nickel vanadate / CNT lithium ion battery negative electrode material prepared by the method has good cycle stability and rate performance.

The application discloses a kind of bismuth-doped carbon nitride photocatalyst and its preparation method and application in NADH regeneration, comprising the following steps: bismuth salt is dissolved with vanadate in concentrated nitric acid, then deionized water is added, and bismuth vanadate precursor solution is formed by stirring violently;Vanadium bismuth precursor solution is transferred to microwave synthesis instrument to carry out microwave synthesis to obtain bismuth vanadate;Synthesized bismuth vanadate and carbon-nitrogen precursor are transferred to porcelain boat, put into tube furnace, slowly heated and calcined under Ar atmosphere, after calcination is finished, the obtained solid product is ground into powder for standby;The obtained powder is added to anhydrous ethanol, washed several times, then centrifugal separation solid, after drying, it is the bismuth-doped carbon nitride photocatalyst prepared.The application is prepared by using the above technology, and the prepared bismuth-doped carbon nitride photocatalyst has good performance in regenerating coenzyme NADH, and has the characteristics of simple preparation method, wide raw material source, good catalytic effect, safety and environmental protection.

The invention belongs to the technical field of wet vanadium extraction, and particularly relates to a method for efficiently separating vanadium and iron in iron vanadate slag. The method comprises the following steps: quickly adding the iron vanadate slag into an alkaline solution with the temperature of 30-100 DEG C for stirring and leaching, controlling the temperature of reaction slurry, reacting for 2-20 minutes, immediately adding ferrite for magnetizing reaction to obtain black slurry, performing magnetic suction sedimentation on the slurry for the sedimentation time of less than 20 minutes until the sedimentation liquid level is clear, performing magnetic suction filtration and separation on a lower-layer precipitation phase, and filtering and separating the lower-layer precipitation phase to obtain the iron vanadate slag. The filtering time is less than 15 minutes, filtrate and supernate are mixed into vanadium-containing alkali liquor, the recovery rate of vanadium reaches 95% or above, the vanadium-containing alkali liquor can be directly used as a raw material for preparing high-purity vanadium pentoxide, and a filter cake is washed with water and then used as a raw material for ironmaking.

The invention provides a surface treatment method which is suitable for a metal base material, and the metal base material is provided with an appearance surface. The surface treatment method includes the following steps. The method comprises the following steps of: firstly, performing surface sand blasting treatment on the appearance surface to form a sand blasting surface; then, an electrolyte is matched, and micro-arc oxidation treatment is performed on the sand blasting surface, so that a micro-arc oxidation surface is formed. Then, forming a coating to cover the micro-arc oxidation surface; wherein the electrolyte comprises the following components: sodium phosphate, sodium silicate, sodium aluminate, potassium fluoride, potassium hydroxide, ammonium vanadate, potassium vanadate, disodium ethylene diamine tetraacetate (Na2EDTA) and sodium tetraborate.

The invention relates to the technical field of metallurgy, in particular to a preparation method of a high-nitrogen vanadium-nitrogen alloy and the high-nitrogen vanadium-nitrogen alloy.The preparation method comprises the following steps that 1, wet-based industrial-grade ammonium vanadate, a graphite carbon powder reducing agent, a metal iron powder catalyst and a water-based binder are mixed and stirred according to the mass ratio of 100: (18-22): (0.2-0.5): (8-20), and a mixture is obtained; 2, the mixed material is subjected to compression molding, and a preformed material is obtained; and 3, the preformed material is sequentially subjected to low-temperature pre-sintering dehydration treatment, high-temperature nitridation reduction treatment and cooling annealing treatment, and the high-nitrogen vanadium-nitrogen alloy is obtained. According to the preparation method, industrial-grade wet-based ammonium vanadate is directly adopted as a raw material, pretreatment is not needed, and the production cost is further reduced.

The invention discloses flaky vanadium pentoxide and a preparation method thereof.The method comprises the steps that ammonium vanadate compounds are sequentially subjected to drying dehydration, deamination and oxidation in hot air flow, and hot-state powdery vanadium pentoxide is obtained; the hot-state powdery vanadium pentoxide is rapidly melted in a microwave and / or electric heating mode; and the molten vanadium pentoxide is rapidly cooled and tableted, and the flaky vanadium pentoxide is obtained. Atmospheric flow generated by combustion of coal gas, natural gas and combustion-supporting air can be greatly reduced, and the service life of the melting furnace is prolonged; meanwhile, a large amount of heat energy consumption required by heating a large amount of gas such as coal gas, natural gas and combustion-supporting air in the melting stage can be greatly reduced; the volume of the melting furnace can be reduced by fully utilizing the characteristic that microwave directly and rapidly heats materials, and the construction and maintenance cost of the melting furnace is further reduced.

Embodiments relate to a metal vanadate catalyst for nitrogen oxide reduction functionalized with H3-APO4A− (A=1, 2, or 3) and SOB2− (B=3 or 4) and a synthesis method thereof, and more particularly, to a solid-state catalyst for nitrogen oxide reduction, including a transition metal vanadate or a rare-earth metal vanadate as a catalytic site in a support, some of the catalytic sites being modified with H3-APO4A− and SOB2− functional groups, and a synthesis method thereof.

The application relates to the technical field of water-based zinc ion battery positive electrode materials, in particular to an ammonium vanadate positive electrode material and a preparation method and application thereof. The application provides a preparation method of an ammonium vanadate positive electrode material, which comprises the following steps: mixing an ammonium metavanadate solution and gas-phase grown carbon fibers, then adding cyclodextrin and anhydrous oxalic acid in sequence, carrying out a hydrothermal reaction, and obtaining the ammonium vanadate positive electrode material. The ammonium vanadate positive electrode material prepared by the method has excellent cycle stability and rate performance.

The application discloses a preparation method and application of a phenolphthalein intercalated ammonium vanadate material. The phenolphthalein intercalated ammonium vanadate material is synthesized by a one-step solvothermal method, ammonium metavanadate is used as a vanadium source, a mixed solution of ethylene glycol and water is used as a reaction medium, and oxalic acid is used as a reducing agent, so that the phenolphthalein intercalated ammonium vanadate material is obtained under a solvothermal condition. The phenolphthalein molecules between layers of the material play a role of a support, and the hydrophobic phenolphthalein molecules can reduce direct contact between the material and water molecules, inhibit structural collapse and dissolution of the material in a cycle process and the like, and the material is applied to a water-based zinc ion battery as a positive electrode material, so that more excellent electrochemical performance and cycle stability are obtained.

The invention relates to a preparation method of gold-doped magnesium vanadate nitride as well as a product and application thereof. The gold-doped magnesium vanadate nitride is prepared through a chemical solution method and nitridation in an argon / ammonia gas mixed atmosphere. Magnesium vanadate is modified through nitridation, so that the diffusivity of ions can be improved, active sites can be increased, an interface is optimized, the electrochemical performance of the material is improved, and the electrochemical performance of the material is further improved through gold doping. The preparation process is relatively simple and easy to operate.

The application relates to a magnetic rare earth doped indium vanadate composite nanosheet and a preparation method thereof, and relates to the technical field of nanometer material synthesis and mass spectrometry analysis. The magnetic rare earth doped indium vanadate composite nanosheet comprises InVO4:Sm nanosheets and Fe3O4 nanoparticles uniformly distributed on the surfaces of the InVO4:Sm nanosheets. A method for preparing the magnetic rare earth doped indium vanadate composite nanosheet comprises the following steps: 1, two kinds of reaction solutions are respectively prepared; 2, InVO4:Sm nanosheets are prepared; and 3, composite nanosheets are prepared. The magnetic rare earth doped indium vanadate nanosheet can be used as a MALDI-MS matrix, is suitable for analyzing small molecule analytes (mass-to-charge ratio less than 1000), has the characteristics of low background interference, high signal-to-noise ratio and good signal stability, and fills the blank of the existing MALDI-MS matrix which is not suitable for analyzing small molecule analytes.

A rare-earth-doped antiferromagnetic crystal is disclosed, designed to achieve long optical coherence times and enable coherent coupling between optical and magnon modes. The crystal includes a host lattice, such as gadolinium vanadate, gadolinium oxide, or gadolinium silicate, which is antiferromagnetic below a Néel temperature and is doped with a second rare-earth ion, such as erbium. By operating at cryogenic temperatures, electron spins in the host are magnetically ordered, providing a quiet magnetic environment that minimizes decoherence for the dopant ions. The system achieves long optical coherence times for the rare-earth dopant ions, supporting robust quantum memory and communication. Additionally, coherent coupling between the optical transitions of the dopant and magnon modes of the host enables efficient microwave-to-optical quantum transduction. Isotopic purification of the host and / or dopant ions can further reduce nuclear spin noise, enhancing coherence times.

The invention discloses a hydrated basic copper vanadate microsphere modified electrode and a preparation method and application thereof, and belongs to the technical field of electrochemical sensor analysis and detection.The hydrated basic copper vanadate microsphere modified electrode is characterized in that a series of hydrated basic copper vanadate microspheres which are different in size, controllable in synthesis process, stable in structure and excellent in electro-catalytic performance are synthesized with benzoic acid as a particle size regulating agent; and modifying the surface of the electrode with the microspheres to obtain the hydrated basic cupric vanadate microsphere modified electrode which has the advantages of rapid current response to large-size ascorbic acid, reasonable linear range, high sensitivity and low detection limit. In addition, the hydrated basic copper vanadate microsphere modified electrode has good reproducibility and stability, and has potential application prospects in the development of ascorbic acid electrochemical sensors.

The present application relates to a magnesium-based hydrogen storage material based on magnesium dihydride and copper vanadate and a preparation method thereof, and belongs to the technical field of hydrogen storage material preparation. The present application mainly coats Cu3(VO4)2 powder on the surface of MgH2 powder through ball milling, and uses Cu3(VO4)2 bimetallic oxide to synergistically catalyze and modify the Mg / MgH2 system, significantly improves the hydrogen absorption and desorption rate of MgH2, obtains a composite hydrogen storage material with excellent low-temperature hydrogen storage performance, and simultaneously achieves the common optimization and improvement of hydrogen absorption kinetics and the total amount of hydrogen absorption and desorption. Compared with single metal oxides and other forms of added bimetallic elements, the present application is to solve the problems of high hydrogen absorption and desorption temperature and slow kinetics of MgH2, realize fast hydrogen absorption and desorption kinetics at medium temperature, that is, realize hydrogen absorption at low temperature (100 DEG C), and have fast hydrogen desorption kinetics at a relatively low hydrogen desorption temperature (for example, 225 DEG C, 250 DEG C).

A porous CaV2O6 / CaSiO3 / g-C3N4 nanocomposite includes a calcium metavanadate (CaV2O6), a calcium silicate (CaSiO3) and a graphitic carbon nitride (g-C3N4) where the CaV2O6, the CaSiO3 and the g-C3N4 are present in a mass ratio of 0.8-1.2:0.8-1.2:0.8-1.2. The CaV2O6 and CaSiO3 present in the nanocomposite forms a structure of homogeneous nanowire and the g-C3N4 forms a structure of a nanosheets where the nanowires are homogeneously distributed between the nanosheets. A method to synthesize the nanocomposite.