1353 results about "Photogenerated electron" patented technology

The invention discloses a porous titanium dioxide/graphene composite material and a preparation method thereof. The preparation method comprises the steps of: adding aniline and graphene into a surfactant-containing protonic acid solution according to a certain ratio; preparing a nanometer polyaniline/graphene composite material through an in-situ polymerization method; preparing titanium dioxide sol by using a sol-gel method; adding 0.05-0.20g of nanometer polyaniline/graphene composite material into 50mL of sol, uniformly mixing; standing and aging the sol for 3-5 days; drying in a drying oven at the temperature of 60-120 DEG C; milling; calcining the obtained composite for 30 minutes -2 hours at the temperature of 200-550 DEG C; and removing the polyaniline, thereby obtaining the porous titanium dioxide/graphene composite material. According to the invention, the porous titanium dioxide/graphene is prepared by utilizing the nanometer polyaniline and the titanium dioxide is deposited on the graphene, so that the contact area of the titanium dioxide and pollutants is increased, the separating efficiency of photo-generated electrons and holes is improved and the photocatalytic efficiency is improved.

The invention discloses a g-C3N4 nanosheet/CdS composite visible-light-driven photocatalyst and a preparing method and application thereof and belongs to the technical field of material preparation and photocatalysis. The catalyst is directly obtained with the solvothermal method by taking two-dimensional ultra-thin g-C3N4 nanosheets as the matrix, cadmium acetate dihydrate and thioacetamide as raw materials, and ethyl alcohol as the solvent. Compared with general block g-C3N4/CdS, the two-dimensional ultra-thin g-C3N4 nanosheet/CdS composite photocatalyst prepared with the method has the advantages that the two substances are in tighter contact, the specific surface area is larger, photon-generated electron-hole can be better separated, and photocatalytic efficiency is higher. Under the shining of sunlight, the composite photocatalyst enables catalytic degradation of organic pollutants such as methyl orange in water to be achieved well. The preparing method is easy, raw materials are easy to obtain, visible light catalysis efficiency is high, and the application prospect is wide in the photocatalysis field.

The invention discloses a preparation method of a Ti3C2/TiO2 two-dimensional material. The preparation method comprises the steps of preparing a Ti3C2MXene film material, carrying out heat oxidation so as to increase interlayer spacing, and generating TiO2 on a Ti3C2 slice layer in situ, so as to obtain the Ti3C2/TiO2 two-dimensional material. By one-step in-situ growth of TiO2 on Ti3C2, the Ti3C2/TiO2 two-dimensional material is obtained. The prepared composite material is large in specific surface area and good in electrical conductivity and has the characteristics of a photo-induced electron cavity pair; and meanwhile, shottky contact is formed between Ti3C2 and TiO2, so that the photocatalysis efficiency of the composite material is improved. The preparation method is simple in process, low in cost and applicable to large-scale application, and furthermore, the Ti3C2/TiO2 composite material is very suitable for being applied to the photocatalysis field.

A system for disinfecting a fluid containing microorganisms or chemical contaminants includes a plurality of photocatalyst surfaces secured to a solid surface upon which a fluid to be disinfected contacts. A structure for removing a portion of the photogenerated electrons is in electrical contact with the photocatalyst layer, wherein an electron-hole recombination rate involving the photogenerated electrons and holes is reduced, thus increasing the removal rate of microorganisms or chemical contaminants from the fluid. The system can include a source of photons having a wavelength corresponding to a band gap energy of the photocatalyst to illuminate the photocatalyst layer. The invention can be used in air supply registers of a heating, ventilating and air conditioning system, or in air ducts, or used to disinfect wall coverings, floor coverings, envelopes, packages, and clothing articles.

The invention discloses bismuth ferrite nano fiber and a preparation method thereof. The preparation method of the bismuth ferrite nano fiber comprises the following steps: 1) using bismuth nitrate or a hydrate thereof and iron nitrate or a hydrate thereof as raw materials, dissolving the two raw materials in a solvent, adding a complexing agent, stirring to obtain bismuth ferrite sol, then adding a polymer as a spinning aid in the bismuth ferrite sol, and stirring evenly to obtain a precursor solution; 2) performing electrostatic spinning of the precursor solution to obtain bismuth ferrite precursor fiber; and 3) performing heat treatment of the bismuth ferrite precursor fiber to remove the polymer to obtain the bismuth ferrite nano fiber. In the BiFeO3 (bismuth ferrite) nano fiber prepared by the preparation method, crystal grains of the fiber are arranged along the axial direction to form a bamboo-joint-like structure. The bismuth ferrite nano fiber has a narrow forbidden bandwidth (2.1-2.3 eV), a high utilization rate of visible light, a large specific surface area and few crystal boundaries and crystal faces, can effectively improve the separation of photogenerated carriers and reduce the recombination rate of photogenerated electrons and holes, has a high quantum efficiency, and shows more excellent photocatalytic properties than nanoparticles.

The invention discloses a graphene composite dye-sensitized solar cell light anode and a preparation method thereof. The light anode of the invention is characterized in that graphene is arranged on the surface of a transparent conductive substrate, the included angle between the platy surface of the grapheme and the surface of the transparent conductive substrate is not equal to 0 degree or 180 degrees, and the included angle is 90 degrees most preferably. Compared with the prior art, the light anode of the invention not only can transfer photo produced electron to an external circuit more quickly and reduce recombination of the electron and electrolyte, but also can reduce absorption area of graphene to light and improve light utilization factor of cell, thus the light anode of the invention can improve photo electricity energy conversion efficiency; and accordingly the photo electricity energy conversion efficiency of the dye-sensitized solar cell adopting the light anode of the invention is improved by 44.7% and 15.8% respectively compared with graphene uncompounded dye-sensitized solar cell and the existing graphene compounded dye-sensitized solar cell.

The invention belongs to the field of nano-materials, and discloses a preparation method of a reduced graphene oxide/bismuth vanadate/carbon nitride Z-type heterojunction composite photocatalyst. The preparation method includes the steps: performing thermal polymerization on urea to prepare graphite phase nitride carbon (g-C3N4); preparing graphene oxide by a Hummers method, and further preparing reduced graphene oxide; preparing a reduced graphene oxide/bismuth vanadate/carbon nitride composite material by a hydrothermal method. The utilization rate of visible light is improved by constructing Z-type heterojunctions, and photoelectric cavitation complex rate is reduced. The material can be used for photodegradation antibiotic pollutants and is of great significance for environmental control.

The invention discloses a synthetic method and application of a visible-light responding carbon nitride/iron sesquioxide nano composite, belongs to the fields of composite preparation technologies and photocatalysis and aims to solve the problems that a conventional carbon nitride material is small in specific surface area, high in photon-generated electron-hole recombination rate, low in solar energy utilization ratio and the like. The composite is prepared by taking melamine and iron nitrate as raw materials and methanol as a solvent and adopting the chemical reaction method and the heat treating process. Compared with carbon nitride, the prepared carbon nitride/iron sesquioxide nano composite has a wider light absorption range (expanded from the ultraviolet region to the visible region), greatly improves the solar energy utilization ratio, meanwhile, has a larger specific surface area, is low in photon-generated electron-hole recombination rate, and can effectively degrade Rhodamin B under visible light. The advantages that the preparation technology is simple, the raw material cost is low, mass production is available, and the obtained composite is large in specific surface area, high in solar energy utilization ratio, excellent in catalytic performance, and good in application prospect are achieved.

The invention provides an in-situ preparation method and application of an Ag/AgCl/NH2-MIL-101(Fe) composite photocatalyst with a spindle appearance, and belongs to the technical field of environmental pollution improvement. The in-situ preparation method comprises the following steps: preparing a NH2-MIL-101(Fe) nanometer material with a regular hexagon-shaped section and a spindle appearance according to a solvothermal method by taking FeCl3.6H2O and 2-amino-terephthalic acid as raw materials, wherein the average length of the edges of the nanometer material is about 700 nm, and the average length of the sides of the regular hexagon-shaped cross section is about 200 nm; preparing the Ag/AgCl/NH2-MIL-101(Fe) composite photocatalyst with the spindle appearance in situ according to an ultraviolet light reduction method. According to the method, the reaction between Cl- in the NH2-MIL-101(Fe) nanometer material and Ag+ in a silver nitrate solution, and the reducing action of ultraviolet light are utilized, and no other exogenous chlorine source is added, so that the in-situ preparation method is simple, convenient, and mild in condition; Ag/AgCl nano-particles are loaded on the NH2-MIL-101(Fe) nanometer material; electron transfer efficiency is further improved via the surface plasma resonance effect, so that the recombination probability of photogenerated electron-hole pairs is reduced, and gaseous pollutants are effectively degraded.

The invention discloses a synthesis method and an application of a porous carbonitride/copper oxide nanorod composite material with visible light response, and belongs to the fields of composite material preparation technologies and photocatalysis. The problems of small specific surface area, high photo-generated electron-hole recombination rate and low quantum yield of present carbonitride materials are solved in the invention. The composite material is prepared from melamine and copper acetate through a chemical reaction process and a heat treatment process with methanol as a solvent. Compared with carbonitride, the porous carbonitride/copper oxide nanorod composite material prepared in the invention has the advantages of high specific surface area, good photocatalysis performance, and effective degradation of rhodamine B under visible light. The preparation method has the advantages of simple process, cheap raw materials and large scale production; and the obtained composite material has large specific surface area, low photo-generated electron-hole pair recombination and good application prospect.

The invention discloses a preparation method of a Ru-Pd/TiO2 nanotube complex photocatalyst and the application thereof, and belongs to the technical field of environment pollution control. When the photocatalyst is prepared, an electrochemical oxidation reaction is performed under the action of hydrofluoric acid with the concentration of 0.2wt percent so as to prepare a TiO2 nanotube electrode firstly, the pipe diameter of a nanotube is about 100 nm, and the thickness of a pipe wall is about 20 nm. Then an impregnating electrodeposition method is adopted to prepare the Ru-Pd/TiO2 nano complex photocatalyst. The method for preparing the complex photocatalyst has the advantages of simple synthesis, stable property, synthesis process belonging to the green chemistry and the like. The composition of Ru and Pd improves the separating efficiency of photoinduced electrons-hole pairs of the TiO2 nanotube electrode, further improves the photocatalytic reduction degradation efficiency of organic pollutants, and has very high utility value and a good application prospect.

The invention belongs to the field of photocatalysis and specifically relates to an AgVO3/Ag3PO4 heterojunction composite photocatalyst and its preparation method and application. The AgVO3/Ag3PO4 heterojunction composite photocatalyst is composed of AgVO3 and Ag3PO4. Ag3PO4 nanoparticles grow in situ on the surface of an AgVO3 nanoribbon, wherein molar ratio of AgVO3 to Ag3PO4 is 1:0.01-1. The preparation method of the invention has a simple process, is easy to control and is low-cost. An AgVO3/Ag3PO4 heterojunction structure with visible light response is constructed, photon-generated carrier separation is accelerated, and recombination probability of photogenerated electron-hole pairs is minimized. The AgVO3/Ag3PO4 heterojunction composite photocatalyst has high-efficiency photocatalytic activity and stability in visible light, has highly-efficient killing and degradation effects on harmful microbes and dye pollutants in a water body and has good practical value and potential application prospect in fields of water body purification and the like.

The invention belongs to the technical field of semiconductor photocatalysis, and particularly relates to a WS2/ZnIn2S4 composite visible light catalyst and a preparation method thereof. The inventionprovides a WS2/ZnIn2S4 composite visible light catalyst and a preparation method thereof. The preparation method is characterized in that a WS2 nano sheet used as a promoter is tightly combined withZnIn2S4 particles through a hydrothermal reaction, thereby forming the WS2/ZnIn2S4 composite visible light catalyst. Compared with a pure ZnIn2S4 photocatalyst, the prepared WS2/ZnIn2S4 composite visible light catalyst can effectively promote separation of photogenerated charges and reduce combination of photogenerated electrons and holes due to the formation of a semiconductor heterostructure, sothat the photocatalytic hydrogen production performance can be greatly improved. The WS2/ZnIn2S4 composite visible light catalyst and the preparation method thereof which are provided by the invention provide a new idea and a new way for design and development of a novel efficient visible light catalyst.

The invention belongs to the field of environmental catalysis, and discloses a photocatalyst for efficiently degrading tetracycline under visible light and a preparation method and application of thephotocatalyst. The preparation method of the photocatalyst comprises the following steps: mixing a nitrogen-containing compound in water, carrying out hydrothermal treatment, cooling, transferring into a culture dish, and carrying out freeze drying treatment to obtain a precursor; and putting the precursor into a closed environment for high-temperature roasting, and naturally cooling to obtain thegraphite-phase carbon nitride photocatalyst for efficiently degrading tetracycline under visible light. According to the preparation method, the raw materials are mixed for hydro-thermal treatment and freeze-drying treatment to obtain the precursor, the graphite-phase carbon nitride obtained through constant-temperature roasting under different conditions has a relatively high specific surface area, and the separation of photo-induced electrons and holes can be effectively promoted through the formation of material defects; therefore, the purpose of efficiently degrading 10 mg/L tetracyclinehydrochloride under visible light is achieved.

The invention provides a cerium oxide, graphene quantum dots and graphene-like phase carbon nitride composite photoactivate material and a preparation method thereof. The composite photoactivate material is formed by embedding cerium oxide into a graphene-like phase carbon nitride layer structure and loading the nitrogen-doped graphene quantum dots onto graphene-like phase carbon nitride. According to the composite photoactivate material, by use of doping of the nitrogen-doped graphene quantum dots, the photoresponse range of the graphene-like phase carbon nitride is expanded; through the quick photoproduction electron and hole separation effect and the electronic migration capability among the nitrogen-doped graphene quantum dots, cerium oxide and graphene-like phase carbon nitride, the composite photoactivate material has an efficient photocatalytic activity.

The invention belongs to the technical field of environment functional materials and relates to a preparation method and application of a C3N4 composite catalytic membrane. The preparation method comprises the following steps: firstly, dissolving AgNO3 and g-C3N4 into water to obtain a solution A; dropwise adding a Na3PO4 solution into the solution A, stirring, washing, centrifugally separating and drying to obtain a binary composite semiconductor material C3N4@Ag3PO4; secondly, dissolving dopamine into a Tris-HCl solution, putting a PVDF membrane into the solution, modifying the dopamine, depositing a polydopamine layer on the surface of the PVDF membrane, and carrying out room temperature drying on the obtained polydopamine modification membrane (PDA@PVDF); dissolving the C3N4@Ag3PO4 into the water, and carrying out ultrasonic dispersion to obtain C3N4@Ag3PO4 suspension; taking PDA@PVDF as a base membrane, and carrying out vacuum filtration and room temperature drying. A silver phosphate nanomaterial is loaded with a graphite nitrogen carbide nano-sheet to form point-surface contact, so that compounding of C3N4 photo-induced electron hole pairs is inhibited, the stability of Ag3PO4 is improved and further the photocatalytic activity is improved; the C3N4@Ag3PO4 is loaded on the PVDF membrane, so that the problems that catalyst powder is difficult to recover and easy to waste,and membrane holes are blocked because of membrane pollution are solved; the removal rate of pollutants is improved.

The invention discloses a bismuth tungstate composite photocatalyst modified by a nitrogen-doped carbon quantum dot and a preparation method and application thereof. The composite photocatalyst is characterized in that bismuth tungstate is taken as a carrier, and is modified with the nitrogen-doped carbon quantum dot. The preparation method comprises the following steps: mixing bismuth nitrate, sodium tungstate and water, and stirring the mixture to obtain a bismuth tungstate precursor solution; mixing the bismuth tungstate precursor solution with a nitrogen-doped carbon quantum dot solution, and stirring the mixture to obtain a mixed solution; performing a hydrothermal reaction to obtain the bismuth tungstate composite photocatalyst. The composite photocatalyst has the advantages of environmental friendliness, high photo-induced electron-hole separating efficiency, high light absorbing efficiency, high photocatalysis activity, high photocatalysis stability and high corrosion resistance; the preparation method has the advantages of simple preparation process, low raw material cost, and easiness in controlling operation conditions. The composite photocatalyst is used for catalyzing degradation of antibiotic wastewater, and has the advantages of simple application method, high degrading efficiency and high repeatability, and has a very good practical application prospect.

The invention relates to a preparation method of core-shell TiO2/ZnO photocatalyst and the application thereof, which relates to the preparation method of a photocatalyst and the application thereof. The invention solves the problem that the valence band electron of the existing photocatalyst can transit onto a conduction band only under the excitation of ultraviolet radiation. The preparation method of the invention is that: 1. Zn(CH3/COO)2/2H2/O is mixed into a Polyvinyl alcohol solution and heated in step after being dried and then cooled down to room temperature; 2. tetrabutyl titanate, absolute ethyl alcohol and triethanolamine are mixed together and aged, then the product of the step 1 is added into the solution for dissolving following by drying and heat treatment. The core-shell TiO2/ZnO photocatalyst prepared by the invention is painted on cross linked ethylene, layered perovskite, molten salt crystal water and salt or Al-Si material as thermal energy storage material. The electron of the TiO2 in the invention can transit onto the conduction band under common lighting condition, which leads photo electron to be effectively separated.

The invention provides a transition metal phosphide/g-C3N4 composite material as well as a preparation method and application thereof. According to the transition metal phosphide/g-C3N4 composite material, transition metal phosphide is loaded on g-C3N4, the compounding of photoelectrons and holes can be remarkably reduced and hydrogen evolution over-potential is reduced, so that the photo-catalytic reaction activity of the g-C3N4 is improved; the transition metal phosphide/g-C3N4 composite material can be applied to a photo-catalytic reaction system and especially can be used in a photo-catalytic water decomposition and hydrogen production system. According to the preparation method provided by the invention, the interface bonding performance of the transition metal phosphide and the g-C3N4 can be improved so that the catalytic activity is improved; furthermore, the preparation method is simple to operate, wide in applicability, good in repeatability and wide applicable range; a reliable scheme is provided for reduction of the photo-catalytic cost and photo-catalytic hydrogen production.

The invention discloses a WO3/TiO2 hollow composite nanotube and a preparation method. TiO2 and WO3 require different spectra in light-catalyzed reaction, and are combined organically to form an effective WO3/TiO2 heterostructure, so that a solar spectrum can be used better. In addition, WO3 nanoparticles organically grow on the internal surface and the external surface of a TiO2 nanotube, so that a specific surface area of the nanotube is increased greatly, and a light-catalyzed reaction speed is increased greatly. The composite nanotube comprises the hollow TiO2 nanotube with a porous structure, and WO3 nanoparticle layers distributed on an external wall and an internal wall of the TiO2 nanotube. The WO3/TiO2 nanotube has excellently-matched crystal lattices, and can accelerate charge separation of photoinduced electrons and holes. TiO2 generates the photoinduced electrons and the holes under irradiation, and performs oxidation-reduction reaction with a pollutant on the surface. The photoinduced electrons and the holes of a WO3/TiO2 composite thin film are obviously better than those of a TiO2 thin film under the irradiation; the oxidation-reduction reaction is accelerated; and the catalytic performance of the thin film is improved.

The invention provides a catalyst for generating hydrogen by visible light photocatalytic reduction of water, and a preparation method thereof, wherein each 100mg of the catalysts contain 10-60mg of eosin-Y, 35-85mg of carbon nano tubes and 1-10mg of oxides. With the technical scheme of the invention, the eosin is used as a sensitizing agent, the carbon nano tubes are used as carriers and photogenerated electron channels, the oxides, such as copper oxide, are used as co-catalysts, so that hydrogen generation by visible light photocatalytic reduction of water is implemented. The catalyst has higher hydrogen generation activity under irradiation of the visible light, and can be used for generating hydrogen by visible light photocatalytic reduction of water. And the oxides substitute Pt to be used as the co-catalyst, thereby implementing non-platinum property of the catalyst.

A heterojunction composite material consisting of one-dimensional In₂O₃ hollow nanotube and two-dimensional ZnFe₂O₄ nanosheets and its application are disclosed. When using this material for catalytic reactions, the hollow cavity and two-dimensional nanosheets of hollow nanomaterials can not only reduce the migration distance to accelerate the electron-hole separation, but also provide a large surface area and rich active sites to promote pollution adsorption and surface catalysis. At the same time, multiple light scattering or reflection in the hollow cavity of the hollow nanomaterials can increase light absorption and utilization. In addition, the heterojunction photocatalyst constructed by growing two-dimensional semiconductor nanosheets on a tubular substrate can promote the effective separation of photogenerated electrons and photogenerated holes, thereby improving the catalytic efficiency. In terms of catalytic performance, In₂O₃ @ ZnFe₂O₄ shows effective degradation of tetracycline, and due to its ferromagnetism, it shows convenient and good separation effect and has good recycling performance.