62results about How to "Improve hydrogen production activity" patented technology

The invention provides a carbon-coated cobalt sulfide material as well as a preparing method thereof and application of the carbon-coated cobalt sulfide material as a catalyst in the aspect of hydrogen production through the electric catalytic cracking of water and belongs to the fields of catalyst synthesis technologies and application. An organic matter rich in sulfur is used as a sulfur source and a carbon source, a cobalt salt is used as a cobalt source, the organic matter and the cobalt salt are forged in an inert atmosphere after being mechanically mixed uniformly, and the carbon-coated cobalt sulfide material can be obtained. The preparing method is simple and controllable, adopts cheap raw materials, has good sample repeatability, spends short time in the synthesis process, has low requirements on equipment and is suitable for massive production. As an active substance is effectively protected by a carbon coating layer from electrolyte corrosion, the electric conductivity of the material is improved, and accordingly, the material shows excellent hydrogen production electric catalysis performance in acid, neutral as well as alkaline electrolytes. The most important is that the development of the catalyst capable of being used in the whole pH range opens a novel path for the preparation of a cheap, efficient and environment-friendly non-noble metal electric catalysis material for hydrogen production.

The invention discloses a carbon dot/carbon nitride/titanium dioxide composite material which is formed by compounding of three-phase carbon dots, graphene-like carbon nitride and titanium dioxide, wherein carbon nitride has a large surface area so as to just provide a depositing space for titanium dioxide nanosheets, so that titanium dioxide cannot cluster; and meanwhile, carbon nitride has relatively narrow energy gap and can increase the light response range. Furthermore, compounding of photo-induced electrons can be further inhibited by utilizing the unique electron transfer capacity of carbon dots, so as to increase the photocatalytic capacity. Moreover, the preparation method is mild in process conditions and low in cost, and the composite material is suitable for large-scale production, and has wide application prospect.

The invention discloses a MoS2/TiO2NTs heterojunction photo-electro-catalyst substituting a noble metal Pt sheet for hydrogen evolution and a preparation method of the MoS2/TiO2NTs heterojunction photo-electro-catalyst. The MoS2/TiO2NTs heterojunction photo-electro-catalyst is synthesized by a two-step method. Firstly, a metal Ti sheet is subjected to anodic oxidation and TiO2NTs having a high specific surface area and gaps is formed by taking a diglycol and HF system as a solvent and the Ti sheet as a titanium source through an anodic oxidation process; secondly, MoS2 is loaded onto the prepared TiO2NTs by taking sodium molybdate and thiacetamide as a Mo source and a S source respectively, and taking diglycol as a solvent through kettle heating. A TiO2 surface layer structure, by using the specific surface area of a MoS2 layer, can improve the absorption to H2O molecules; in addition, MoS2 has excellent electron conduction ability and side belt effect, so that the number of reaction active sites are increased; photoelectrocatalysis collaboration can effectively separate electrons from cavities, so that the photocatalysis activity is improved, and hydrogen can be produced rapidly and efficiently by the decomposition in the presence of the MoS2/TiO2NTs heterojunction photo-electro-catalyst.

The invention discloses a TiO2 photocatalyst for photocatalytic reforming biomass hydrogen preparation. A crystal phase composition of anatase and rutile phases can be regulated in a wide range and is obtained by calculating the strengths of a stronger anatase diffraction peak (101) and a stronger rutile diffraction peak (110) on XRD. The TiO2 photocatalyst applied in the photocatalytic reforming biomass hydrogen preparation reaction greatly improves the hydrogen generation activity and effectively inhibits the generation of carbon monoxide, wherein in photocatalytic reforming methanol reaction, the hydrogen generation activity of the TiO2 photocatalyst is about five times that of a TiO2 reference agent (P25), and the CO content of the hydrogen is at least reduced by two orders of magnitude, even below 5ppm.

The invention discloses a two-dimensional nanosheet composite photocatalyst with bimetallic nanoparticles as heterojunctions. The two-dimensional nanosheet composite photocatalyst is composed of a photocatalytic active component and the bimetallic nanoparticles uniformly distributed on the photocatalytic active component by virtue of a binding agent, wherein the photocatalytic active component is a two-dimensional g-C3N4 nanosheet, the binding agent is 0.1-5wt% Nafion perfluorinated resin solution, and the bimetallic nanoparticles are Pd-Ag bimetallic nanoparticles. Raw materials used by the composite photocatalyst are environment-friendly materials respectively, and the Pd-Ag bimetallic nanoparticle heterojunctions have surface plasma resonance effect and interface schottky effect and can more effectively utilize visible light and inhibit recombination of photo-induced electrons and holes, so that the composite photocatalyst disclosed by the invention has high activity and good stability when being applied to hydrogen production through photocatalytic decomposition of water.

The invention belongs to the technical field of photocatalytic material preparation, and relates to a preparation method of a porous carbon nitride photocatalyst. The method concretely comprises the following steps: (1) putting melamine in a ceramic crucible and heating to a certain temperature in a tube furnace to obtain a carbon nitride precursor; (2) collecting the obtained carbon nitride precursor, grinding, and then weighing a certain amount to be horizontally paved in a ceramic ark; and (3) putting the ark, which is loaded with the carbon nitride precursor, into the tube furnace, and calcining in a pure oxygen atmosphere to obtain a porous carbon nitride material. The method has the advantages that the preparation process is simple and easy to operate, and any template agents and corrosive chemical reagents such as strong acid and strong base are not adopted, thereby being green and environment-friendly; the prepared porous carbon nitride photocatalyst has an enlarged specific surface area and shows good photocatalytic water decomposition hydrogen generating performance and light current responsiveness, and the used raw materials are cheap, easy to obtain and convenient for volume production.

The invention discloses a visible light driven NiSe-based heterojunction photocatalyst for performing efficient photocatalysis on water to perform pyrolysis to produce hydrogen. The heterojunction photocatalyst is prepared by the following steps: preparing Cd0.5Zn0.5S sosoloid by taking cadmium acetate, zinc acetate and thioacetamide as cadmium, zinc and sulfur sources correspondingly and adoptinga precipitation-hydrothermal method; and taking nickel sulfate hexahydrate, sodium selenite and the synthesized Cd0.5Zn0.5S sosoloid as substrates, taking glycol as a solvent and a reducing agent, and synthesizing a NiSe/Cd0.5Zn0.5S heterojunction photocatalyst through a one-step solvent-thermal method. The maximum hydrogen production rate of the heterojunction photocatalyst under visible light reaches 70.3 mmol/h/g, and the activity of the heterojunction photocatalyst is 2.35 times that of pure Cd0.5Zn0.5S sosoloid; furthermore, the preparation method is green, environmentally-friendly, simple to operate and stable in activity, the utilization rate of sunlight, particularly visible light by the photocatalyst is greatly increased, and higher economic benefit can be achieved.

The invention belongs to the technical field of semiconductor photocatalysts, and particularly relates to a preparation method and application of a nitrogen defect/boron doped tubular carbon nitride photocatalyst. The preparation method comprises the following steps: putting melamine and phosphoric acid into a high-pressure kettle containing deionized water to carry out hydrothermal reaction, washing the reacted product with deionized water, carrying out vacuum drying to obtain a substance which is a supramolecular precursor, conducting calcining again, naturally conducting cooling and conducting grinding to obtain tubular carbon nitride; mixing tubular carbon nitride and NaBH4, then conducting uniform grinding, and putting the mixture into a porcelain boat for calcination; and washing the calcined product with HCl and distilled water, and carrying out vacuum drying to obtain the nitrogen defect/boron doped tubular carbon nitride photocatalyst, which is marked as a D-TCN photocatalyst. The synergistic effect of nitrogen defect/boron doping and the tubular structure can effectively promote light capture, accelerate charge transfer and promote exposure of more active sites, and the effects of photocatalytic degradation of antibiotics and decomposition of water to produce hydrogen activity can be remarkably enhanced.

The invention discloses a preparation method of a phosphorus-doped cadmium sulfide supported nickel carbide quantum-dot nanorod photocatalyst. The preparation method includes the steps of 1) mixing CdS nanorods and NaH2PO2, heating the mixture in N2 atmosphere to obtain phosphorus-doped CdS nanorods; 2) dissolving the phosphorus-doped CdS nanorods in N,N-dimethylformamide, adding Ni(NO3)2 6H2O and2-methylimidazole, and stirring at room temperature to obtain a precursor material; 3) heating the precursor material of the step 2), holding the temperature, cooling to room temperature, washing with deionized water and ethanol to obtain a black-green product, and drying the black-green product to obtain the phosphorus-doped cadmium sulfide supported nickel carbide quantum-dot nanorod photocatalyst. The photocatalyst prepared via the preparation method has good stability and high visible light catalytic activity, and the preparation method is simple.

The invention relates to a method for preparing a graphite-phase carbon nitride visible-light-induced photocatalyst by copolymerization of 2-aminoterephthalic acid and an amine compound. The method comprises the following steps: uniformly mixing the amine compound and the 2-aminoterephthalic acid to obtain mixed powder, and calcining the mixed powder at 520-600 DEG C to obtain the graphite-phase carbon nitride visible-light-induced photocatalyst. The preparation method is simple, and the obtained novel graphite-phase carbon nitride has better visible light catalytic hydrogen production performance compared with original carbon nitride.

The invention belongs to the technical field of material preparation and photocatalysis, and particularly relates to an MMoS4/g-C3N4 (M is equal to Co, Ni, Cu) composite photocatalytic material, and apreparation method and application thereof. MMoS4 particles are loaded on graphite phase carbon nitride through a coprecipitation method so as to form the composite photocatalytic material; the preparation method has the advantages of simple and convenient preparation process, low coat, and easy large-scale industrial production; the prepared composite photocatalytic material has a heterojunctionstructure formed by compounding ternary metal sulfide and g-C3N4, so that the separation of a photon-generated carrier is greatly promoted, a surface hydrogen production dynamic behavior is improved,the hydrogen production activity of a photocatalyst is remarkably improved, and the photocatalytic material has favorable environmental stability and can be applied to visible light photocatalysis hydrogen production in an alcohol-water system.

The invention discloses an anthemia-shaped NiS/ZnS visible light photocatalyst and a preparation method thereof, the anthemia-shaped NiS/ZnS visible light photocatalyst comprises the following raw materials by weight: 1-5 parts of an inorganic zinc salt, 2-10 parts of thioacetamide or thiourea, 38-50 parts of ethanolamine or ethylenediamine, and 0.01-0.02 part of an inorganic nickel salt. The method is as follows: adding the inorganic zinc salt and thioacetamide or thiourea into a container filled with the ethanolamine or ethylenediamine, stirring evenly at less than 45 DEG C, standing for 15-20min to obtain suspension; reacting in microwave at the temperature of 140-150 DEG C for 4-5min, cooling a reaction kettle to room temperature to obtain an anthemia-shaped ZnS complex precursor; reacting in microwave at the temperature of 140-150 DEG C for 20-25min to obtain a primary product, centrifugally drying to obtain the anthemia-shaped NiS/ZnS visible light photocatalyst. The anthemia-shaped NiS/ZnS visible light photocatalyst has the advantages of simple method operation, low cost and wide raw materials, can be recycled, has excellent visible light photocatalytic hydrogen production activity under visible light irradiation, and can promote photocatalytic hydrogen production industrialization.

The invention discloses a heterojunction photocatalyst for hydrogen production and alcohol oxidation by high-efficiency photocatalytic water-cracking, and belongs to the field of photocatalyst preparation and application. According to the invention, nickel sulfate hexahydrate, sodium selenite and titanium dioxide are taken as reactants, glycol is taken as a solvent and a reducing agent, and then aNiSe/TiO2 heterojunction photocatalyst is synthesized according to a one-step solvothermal method. The heterojunction photocatalyst prepared by the invention has a photocatalytic hydrogen productionperformance 9 times higher than that of pure TiO2, and shows good stability in the long-cycle operation. Furthermore, simple alcohols are taken as sacrificial agents, and chemicals of high-value fuel(hydrogen), small molecular acids, aldehydes and the like are prepared through the photocatalytic water cracking under illumination of simulated sunlight. In addition, the heterojunction photocatalystused in the invention is green and simple in preparation method, rich in material sources, low in cost and stable in activity, and combines the small molecular alcohols as the sacrificial agents, sothat economic benefits of photocatalysis and the utilization rate of absorbed light energy can be greatly improved.

The invention provides a Ru monatomic and g-C3N4 composite photocatalyst and a preparation method and application thereof, and belongs to the technical field of nano material synthesis. According to the device, Ru monatomic is loaded on the surface of g-C3N4 by utilizing a simple and rapid one-step calcination method, so that the Ru monatomic and g-C3N4 composite photocatalyst is formed; the photocatalyst can efficiently and stably produce hydrogen through water photolysis under visible light.

The invention discloses a Nb-Rh co-doped titanium dioxide nanorod photocatalyst, and a preparation method and application thereof. The photocatalyst of the invention has the following advantages: 1) the photocatalyst prepared in the invention has a one-dimensional rod structure and is effectively improved in photocatalytic hydrogen production activity compared with a common photocatalyst; 2) the preparation method of the photocatalyst is simple and can easily realize large-scale commercial production; 3) the photocatalyst can be reused, and the catalytic activity of the Nb-Rh co-doped titaniumdioxide nanorod photocatalyst is free of obvious decline after reuse 20 times or more; and 4) the Nb-Rh co-doped TiO2 nanorod photocatalyst has high catalytic activity, e.g., a Ti<0.996>Nb<0.002>Rh<0.002>O<2> nanorod photocatalyst has a hydrogen production rate of up to 7.58 mmol/g.h in photolysis of water, which is 194 times the hydrogen production rate (0.039 mmol/g.h) of TiO2 nanorods preparedunder the same conditions.

The invention discloses a preparation method and application for a morphology-controlled CdSe-modified porous TiO2 material. The preparation method comprises the following steps: Step I: synthesizingmonodisperse polystyrene microspheres (PS) with an average diameter of 500 nm; Step II: preparing CdO-TiO2 intermediate: preparing CdO-TiO2 intermediate by using the polystyrene microspheres obtainedin Step I) as a template in a sol-gel method; Step III: preparing nanosheets, nanorods and nano-conical CdSe particle-modified porous TiO2 photocatalyst in a two-step method. By means of the material,optically stimulated electrons can be transferred from a conduction band of CdSe to a conduction band of TiO2, the porous structure also improves active sites of the reaction, and the hydrogen production activity is improved. The growth-controlled composite material designed based on a reasonable material can obtain very good hydrogen evolution speed under visible light without any precious metalas a promoter.

The invention discloses a method for preparing a graphene-titanium dioxide composite photocatalyst. The method comprises the following steps: 1, mixing graphite powder with NaNO3, carrying out a microwave reaction, and naturally cooling the obtained reaction product to room temperature; 2, adding a mixture obtained in step 1 into concentrated sulfuric acid in an ice water bath state, stirring andmixing the mixture and the concentrated sulfuric acid, and adding KMnO4; 3, placing a system obtained in step 2 in an oil bath, adding a hydrogen peroxide solution until the system generates no bubbles, washing the obtained precipitate, and carrying out vacuum drying on the precipitate to obtain graphite oxide; 4, adding the graphite oxide into an ethanol and water mixed solution, and carrying outultrasonic treatment; and 5, adding titanium dioxide, carrying out a stirring reaction at 150 DEG C, naturally cooling the obtained reaction product to room temperature, filtering the cooled product,washing the obtained precipitate, and carrying out vacuum drying to obtain the graphene-titanium dioxide composite photocatalyst. The graphene-titanium dioxide composite photocatalyst is prepared through a hydrothermal technology, and the hydrogen generation activity of the photocatalyst is high.

The invention discloses an efficient nanocrystal colloidal hydrogen production catalyst and a preparation method thereof. The technical scheme is that a cobalt dichloride solution, a g-C3N4 powder ultrasonic dispersion solution and a PVP colloidal solution are mixed according to a certain ratio under the condition of a certain temperature, and then, a nanocrystal colloidal material with g-C3N4/Co3O4 photoresponse reinforced catalytic hydrogen production performance is prepared by using a hydrothermal synthesis method. The preparation method provided by the invention is simple in operation, lowin cost, safe and environment-friendly; and the prepared g-C3N4/Co3O4 nanocrystal colloidal material has relatively small nanocrystal size, good dispersibility and efficient photoresponse reinforcedcatalytic hydrogen production performance.

The invention discloses a high-efficiency hydrogen-production ZnO core-shell nanorod array photocatalyst. The high-efficiency hydrogen-production ZnO core-shell nanorod array photocatalyst comprises an insulation substrate, the ZnO nanorod arrays are distributed on the substrate, the ZnO nanorod arrays are composed of several ZnO nano rods; the outer layers of the ZnO nanorods are a WS2 films, which form a ZnO-WS2 composite system; the outer layers of the ZnO-WS2 composite system is loaded with CdS nanoparticles to form the ZnO-WS2-CdS core-shell nanorod arrays. The invention also provides a preparation method of the photocatalyst and an application of the photocatalyst for hydrogen production under visible light catalysis. The photocatalyst of the present invention has an effective electron transfer energy level, achieves rapid carrier separation, and increases hydrogen production activity.