33results about How to "Lower bandgap energy" patented technology

The invention provides a preparation method for transition of photocatalysis material on Yb3+-Er3+-Tm3+ doped CaF2 matrix loaded Cr3+-Bi2WO6, which comprises the following steps: 1. adding hydrofluoric acid into a nitrate liquid, uniformly stirring, and obtaining a colloidal solution A; 2. placing the colloidal solution A into a reaction vessel, centrifuging, drying, calcining, and obtaining the powder B; 3. adding powder B into the aqueous solution of Bi(NO3)3x5H2O, stirring and obtaining the colloidal solution C; 4. adding the aqueous solution of Na2WO4x2H2O into the colloidal solution C, stirring and obtaining the colloidal solution D; 5. adding Cr(NO3)3x9H2O into a colloidal solution D, stirring and obtaining the colloidal solution E; 6. 2. placing the colloidal solution E into a reaction vessel, centrifuging, drying, calcining and obtaining the product; The invention improves the utilization efficiency of sunlight, simple preparation technology and low cost.

The invention discloses a preparation method for functional wood capable of degrading organic pollutants through photocatalysis. The preparation method comprises the following steps that wood is subjected to pretreatment, internal pores of the wood are gotten through, and hydroxyl on the surface of the wood is exposed; bismuth nitrate is taken to be dissolved in an acid solution, then, coupling agents are added, stirring is conducted, and a mixed solution is obtained; soluble iodized salts and soluble chlorate are taken to be dissolved in water, stirring is conducted for dissolving, and a halide salt solution is obtained; the pretreated wood is soaked into the mixture solution, subjected to pressurized soaking, taken out and dewatered, and the wood adsorbed with bismuth ions is obtained; the wood adsorbed with the bismuth ions is soaked into the halide salt solution, subjected to pressurized soaking, taken out and subjected to vacuum drying, and then the functional wood capable of degrading the organic pollutants through photocatalysis can be obtained. The functional wood prepared through the method is high in light use ratio, can effectively degrade the organic pollutants under visible light radiation and is good in degradation effect.

The invention discloses an iron-nitrogen-doped titanium dioxide-loaded carbon fiber composite photocatalyst and a preparation method thereof, and belongs to the technical field of photocatalysts. The iron-nitrogen-codoped titanium dioxide-loaded carbon fiber composite photocatalyst ((Fe,N)/TiO2@CF for short) is prepared through sol and gel and an impregnating method; by introducing iron atoms and nitrogen atoms into the photocatalyst, the impurity energy level is introduced between a conduction band and a valence band of TiO2, the band-gap energy of the photocatalyst is reduced, and the visible photocatalytic performance of the photocatalyst is improved; loaded carbon fibers (CF for short) are utilized, therefore, the material is easy to recycle, the reuse performance of the photocatalyst is improved, effective migration of photo-induced electrons is improved, the recombination probability of electron holes is decreased, and the photo quantum efficiency of a catalytic material is improved.

The invention belongs to the technical field of composite photocatalysts, and relates to biomass charcoal degradation of ammonia nitrogen, in particular to a self-assembling carbon nitride-TiO2/hollowstructure biomass charcoal degradation ammonia nitrogen composite. The composite is composed of hollow structure biomass charcoal (HSBC), sheet carbon nitride and TiO2 microspheres of the grading structure, wherein the HSBC is formed by adopting biomass as raw materials through smashing and carbonization, and the hollow aperture is 10-50 micrometers; the sheet carbon nitride is formed by self-assembling, and the thickness is 100-200 nanometers; the grading structure TiO2 microspheres are obtained through hydrothermal in-situ growth, the diameter of the microspheres is 1-2 micrometers, and themicrospheres are composed of dense nano-rods. The invention further discloses a preparation method of the material. The preparation conditions are simple, the high specific surface area of the HSBC and the photocatalysis performance of TiO2 and carbon nitride are combined, and ammonia nitrogen can be rapidly removed. The composite is low in cost, stable, free of secondary contamination and environmentally friendly; ammonia nitrogen wastewater is removed through experiment simulation, and the removal rate under ultraviolet irradiation reaches up to 90.3%.

The invention discloses a wastewater treatment agent. The wastewater treatment agent is formed by coating a magnetic carrier nano-Fe3O4 with SiO2, then loading a porous high-surface-area nano-TiO2 andZn-MOF material, and carrying out doping with N, S and C. The invention also discloses a preparation method of the wastewater treatment agent. The porous structure of Zn-MOF is beneficial to the adsorption and degradation of organic matter in wastewater on the surface of the water treatment agent, the synergistic effect of Zn-MOF and N, S and C doping on TiO2 can reduce the band gap energy of TiO2 and improve the catalytic oxidation performance of TiO2 on organic matter, the magnetic carrier is beneficial to the catalyst recovery, and thus the wastewater treatment agent has great significancefor optimizing the wastewater treatment process and reducing the wastewater treatment cost.

Various embodiments of the present disclosure pertain to separating nitride films from growth substrates by selective photo-enhanced wet oxidation. In one aspect, a method may transform a portion of a III-nitride structure that bonds with a first substrate structure into a III-oxide layer by selective photo-enhanced wet oxidation. The method may further separate the first substrate structure from the III-nitride structure.

The invention belongs to the technical field of water pollution photocatalysts and relates to a hollow-structure biomass charcoal/TiO2 multi-wall tube/CuO photocatalyst. The hollow-structure biomass charcoal/TiO2 multi-wall tube/CuO photocatalyst is prepared through compounding hollow-structure biomass charcoal, TiO2 multi-wall tubes and CuO nanoparticles. The invention further discloses a preparation method of the photocatalyst; the preparation method comprises the following steps: pre-treating biomasses through washing, crushing, acid washing and the like; after dissolving the biomasses intoa titanium solution, carrying out ultrasonic treatment for 20 to 40min; drying for 4 to 8h at 40 to 60 DEG C, so as to obtain a titanium source/biomasses; putting the titanium source/biomasses into amuffle furnace and carrying out high-temperature calcination for 2 to 6h; immersing into a copper solution for 3 to 6h; after washing, immersing into a copper solution and washing; after repeating for 10 to 20 times, drying for 10h at 50 to 70 DEG C; finally, carrying out high-temperature calcination for 2 to 4h under the protection of nitrogen gas and naturally cooling to obtain the photocatalyst. The preparation method disclosed by the invention is controllable and has simple reaction conditions; the high specific surface area of the hollow biomass charcoal is combined with the photocatalysis performance of TiO2 and the catalysis performance of CuO, and ammonia nitrogen is efficiently and rapidly removed. Ammonia nitrogen wastewater is removed through experimental simulation and the highest removal rate under the irradiation of ultraviolet rays reaches 99.5 percent.

The invention relates to a zinc oxide nanorod ternary composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: obtaining biochar: removing spongy parts of shaddock peels, drying the shaddock peels, grinding the shaddock peels into powder, sieving the powder, and carbonizing the powder in a protective atmosphere; then immersing the carbonized product into an alkaline solution, heating, cooling, washing and drying to obtain biochar; and preparing the composite material: dispersing the biochar in a solvent, adding zinc acetate, an alkaline reagent, polyethylene glycol and graphene oxide, uniformly mixing, loading into a high-pressure reaction kettle, heating to react, cooling to room temperature, filtering, washing and collecting a solid product. The zinc oxide nanorod ternary composite material disclosed by the invention has a good photocatalytic effect on tetracycline hydrochloride, the tetracycline degradation efficiency reaches 99.24% after the tetracycline nanorod ternary composite material is mixed with a tetracycline hydrochloride solution, dark adsorption is performed for 40 minutes, and irradiation is performed for 80 minutes under a 75W mercury lamp, so that a new way and a new method are provided for tetracycline wastewater degradation.

The invention discloses a tourmaline TiO2 composite material preparation method, and belongs to the field of composite materials. The tourmaline TiO2 composite material preparation method comprises: mixing and uniformly stirring titanium tetraisopropanolate and ethanol according to a volume ratio of (3-4):10; uniformly dispersing tourmaline powder in a mixing solution comprising ethanol and water according to a volume ratio of 2:1 so as to make the mass fraction of the tourmaline is 5-9%; carrying out ultrasonic dispersion for 1 h with ultrasonic waves with a power of 100 W; mixing the tourmaline/ethanol/water solution and the titanium tetraisopropanolate/ethanol solution, and continuously stirring the sol mixture until generating a brown gel; transferring the brown gel mixture into a reaction kettle, carrying out a solvothermal reaction for 24 h at a temperature of 120 DEG C, and drying the wet gel after completing the reaction to obtain a dry gel, wherein the heating rate is 1 DEG C/min; and carrying out a heat treatment on the dry gel for 24 h at a temperature of 100 DEG C, and washing three times with distilled water at a room temperature to obtain the tourmaline TiO2 composite material. The prepared TiO2 composite photocatalyst of the present invention has advantages of low cost and no pollution, and can directly use solar energy to perform degradation.

The invention mainly aims to provide anatase type titanium dioxide nanocrystalline as well as a preparation method and application thereof. The preparation method comprises the following steps: 1) adding a morphology control agent and a titanium source into a solvent, and uniformly stirring to obtain a precursor solution, wherein the solvent at least comprises acetic acid, and the morphology control agent is selected from at least one of hexadecyl trimethyl ammonium bromide and hydrofluoric acid; 2) carrying out solvothermal reaction on the precursor solution at 150-220 DEG C for 12-72 hours,and performing centrifuging, washing, drying and grinding treatment to obtain the anatase titanium dioxide nanocrystal. The technical problem to be solved is how to generate a crystalline phase only through solvothermal reaction without high-temperature calcination, so that the hydrolysis process of the reaction is controlled, and titanium dioxide nanocrystals with various microstructures and sizes are obtained. The method is simple to operate, low in cost and high in yield, industrial popularization is very easy to realize, and meanwhile, the application range of the titanium dioxide nanocrystal is widened, so that the method is more practical.

The invention belongs to the technical field of composite material preparation, relates to a photocatalytic degradation ammonia nitrogen material, and in particular relates to a hiberarchy biomass carbon fiber/TiO2 photocatalytic degradation ammonia nitrogen material which consists of a biomass carbon fiber and hiberarchy TiO2 nanowires, wherein the biomass carbon fiber is prepared by extracting cellulose and carbonizing biomass as a raw material and has the diameter of 2-10mu m; the hiberarchy TiO2 nanowires are made through seed method hydrothermal in-situ growth, have the diameter of 100-200nm and have the length of 1-5mu m. The invention further discloses a preparation method of the material, and application of the material as a photocatalyst for removing ammonia nitrogen in water. Thepreparation process is controllable, the reaction conditions are simple, and with the combination of a high specific surface area of the biomass fiber and the photocatalytic performance of TiO2, thepurpose of effectively and rapidly removing ammonia nitrogen can be achieved. Removal of ammonia nitrogen wastewater is simulated through experiments, and results show that the removal rate is as highas 97.3% under radiation of ultraviolet rays, and reliable theoretical and practical support are provided for actual application.

The invention belongs to the field of nanomaterial preparation and environmental protection, and discloses a preparation method of a composite photocatalyst Ag/ZnO/CdS. The method comprises the following steps: 1) subjecting cadmium salt, sulfide and polyvinylpyrrolidone to reacting under a high-temperature condition to prepare a hexagonal crystal phase CdS crystal; 2) respectively dissolving sodium hydroxide and zinc acetate into absolute ethyl alcohol, and conducting mixing to obtain ZnO sol; 3) respectively dissolving zinc nitrate and hexamethylenetetramine in deionized water, and conducting mixing to obtain a ZnO solution; 4) dispersing the CdS crystal into the ZnO sol, carrying out a water-bath reaction in the ZnO solution to obtain a dispersion liquid containing ZnO/CdS, and carrying out centrifuging, washing and drying to obtain ZnO/CdS; and 5) dispersing the ZnO/CdS powder in an aqueous triethanolamine solution, then adding a silver nitrate solution, and performing stirring under the irradiation of a light source to obtain the composite photocatalyst Ag/ZnO/CdS. The preparation method is mild in conditions and simple in materials, and the composite photocatalyst is uniform in particle, high in stability, high in photocatalytic activity, excellent in antibacterial property and good in application prospect.

The invention discloses a hydrogen sulfide sensor with a black phospho-TiO2 nanotube/Ti sensitive electrode. The sensor comprises a sensor shell and a membrane electrode arranged in the sensor shell,an air chamber is arranged between the sensor shell and the membrane electrode, a gas reaction chamber is arranged in the membrane electrode, and the membrane electrode comprises a cathode diffusion layer, a cathode catalyst layer, a Nafion membrane and a black phospho-TiO2 nanotube/Ti sensitive electrode from outside to inside; the cathode diffusion layer is connected with the sensor shell through a welding point to form a cathode output end, the black phospho-TiO2 nanotube/Ti sensitive electrode is connected with the sensor shell through a welding point to form an anode output end, and a gasfiltering cap with diffusion holes is arranged at a top end of the gas reaction chamber to allow hydrogen sulfide gas to be detected to pass through; an air circulation hole cover communicated with the air chamber is arranged on the sensor shell, a water discharge hole is formed in the bottom of the air chamber, and an SO2 discharge hole is formed in the bottom of the black phospho-TiO2 nanotube/Ti sensitive electrode. The sensor provided by the invention has good selectivity on hydrogen sulfide gas and strong anti-poisoning and anti-interference capabilities.

The invention belongs to the technical field of cell catalysts, and discloses a direct methanol fuel cell anode catalyst and a preparation method thereof. The preparation method comprises the steps: pretreating a titanium plate, and removing surface oil stains to obtain a rough surface; carrying out anodic oxidation of the pretreated titanium plate, performing washing through deionized water, performing drying and roasting to obtain TiO2 nanotube/Ti; performing heat treatment of red phosphorus, removing oxides and impurities on the surface, and performing grinding after cooling; putting TiO2 nanotubes/Ti into a tubular furnace, putting ground red phosphorus around the TiO2 nanotubes/Ti, introducing argon into the tubular furnace, performing heating and then cooling, performing further cooling to form a black phosphorus nano layer, and depositing the black phosphorus nano layer on the surface of the TiO2 nanotubes/Ti to obtain the anode catalyst for the direct methanol fuel cell. The obtained anode catalyst of the direct methanol fuel cell has high catalytic activity and CO poisoning resistance to methanol, and is low in cost.

The invention relates to the technical field of photocatalytic hydrogen production, and discloses a Co-modified Ni<2+> doped modified Ta3N5 photocatalytic hydrogen-producing material and a preparationmethod thereof. The hydrogen-producing material comprises the following formula raw materials: TaCl5, NiCl2, Co (OH) 2. The invention relates to a Co-modified Ni<2+> doped modified Ta3N5 photocatalytic hydrogen-producing material and a preparation method thereof, the doping of Ni<2+> can enhance the electronic conductivity of Ta3N5, the energy band structure and surface structure of Ta3N5 are optimized, the band gap energy of Ta3N5 is reduced, the ion defects produced by doping can capture the photogenerated carriers, the recombination efficiency of carriers is reduced, the photogenerated electrons and holes recombination is inhibited, surface ion defects can form more photocatalytic active sites, during the calcination process in ammonia atmosphere, metalloid nitrocobalt compounds are generated, which enhances the electron transport performance of Ta3N5 and promotes the separation and transport process of photo-generated carriers. At the same time, low valence nitrocobalt compounds can inhibit the autoxidation process of Ta3N5 and inhibit oxidation of N<3-> ions to N<2-> ions and avoid the decomposition of Ta3N5.

The invention discloses a preparation method of an oxygen-sulfur double-doped carbon nitride visible light catalytic material, a visible light catalytic material and a method for degrading micro-plastics in water, the preparation method comprises the following steps: (1) preparing sulfur-doped carbon nitride by using a pre-doping method: mixing melamine and thiourea according to a mass ratio of (1: 8)-(1: 12); sintering at a high temperature in a nitrogen atmosphere to obtain sulfur-doped carbon nitride; and (2) preparing oxygen-sulfur double-doped carbon nitride by using a post-doping method, namely mixing the sulfur-doped carbon nitride obtained in the step (1) with a hydrogen peroxide solution in a mass ratio of (1: 25)-(1: 35), and reacting at 140-160 DEG C for a certain time to obtain the oxygen-sulfur double-doped carbon nitride visible light catalytic material.

The invention belongs to the field of nano material preparation and environmental protection, and discloses a preparation method of an oxygen-vacancy-enriched multivalent cobalt in-situ doped ZnO flower-like microsphere composite photocatalyst. The preparation method comprises the following steps: (1) dissolving cobalt acetate, zinc acetate, organic weak base and a template agent in deionized water, placing the solution in a reaction kettle which is 1.25-2 times of the total volume of the solution, and reacting for several hours at high temperature to prepare a catalyst precursor; (2) cleaning the catalyst precursor with deionized water, centrifugally collecting a solid product, and drying in a vacuum drying oven at 40 DEG C for 72 hours; and (3) calcining the dried catalyst precursor at a high temperature in a tubular muffle furnace at a certain heating rate in a nitrogen environment for several hours to obtain the oxygen-vacancy-enriched multivalent cobalt in-situ doped ZnO flower-like microsphere composite photocatalyst. The photocatalyst is regular in morphology, uniform in size and high in stability, has high photocatalytic activity under visible light, and has good practical value and application prospects.