48results about How to "Good photocatalytic effect" patented technology

The present invention provides a g-CNQDs / GO composite photocatalysis material preparation method. The concrete scheme of the method comprises that graphite powder, urea and concentrated nitric acid are used as main raw materials, an electrostatic coupling method is used, and four steps such as oxidation of graphene, oxidation of graphite phase carbon nitride quantum dots, oxidation of protonated graphite phase carbon nitride quantum dots, and g-CNQDs / GO compounding are performed to prepare the graphite phase carbon nitride quantum dot / graphene oxide composite photocatalysis material. According to the present invention, the photocatalytic property test on the prepared composite photocatalysis material is performed with visible light ([lambda] is more than 420 nm), and the results of the degradation on rhodamine B, methyl orange and other organic dyes show that the composite photocatalyis material has the excellent photocatalytic performance under the visible light.

The invention discloses a lightweight high-strength water permeable brick with a photocatalysis effect. The lightweight high-strength water permeable brick comprises a reverse osmosis layer, a water permeable layer and a photocatalysis layer in sequential distribution from bottom to top. The photocatalysis layer is coated with a cement-based material with a photocatalysis property; the water permeable layer is formed by pouring of ceramsite-doped regenerated lightweight aggregate concrete; the reverse osmosis layer is also formed by pouring of ceramsite-doped regenerated lightweight aggregate concrete. The lightweight high-strength water permeable brick structurally comprises three layers, namely the photocatalysis layer, the water permeable layer and the reverse osmosis layer, from top to bottom, and each of the three layers has certain porosity. The photocatalysis layer is capable of effectively treating motor vehicle exhaust; the water permeable layer is effective in water drainage; the reverse osmosis layer is effective in reduction of influences of the heat island effect on the environment.

The invention provides a preparation method for a nanometer titanium dioxide-silicon dioxide composite photocatalyst with a core shell structure. The preparation method comprises the following steps: (1) preparing a nanometer titanium dioxide-carbon-silicon dioxide compound with a core shell structure; (2) arraying the nanometer titanium dioxide-carbon-silicon dioxide compound with the core shell structure on a prepreg so as to form a single-layer structure; (3) corroding the prepreg with the nanometer titanium dioxide-carbon-silicon dioxide compound by using steam of a corrosive agent to remove a part of silicon dioxide shells in the nanometer titanium dioxide-carbon-silicon dioxide compound so as to form openings; (4) subjecting the corroded nanometer titanium dioxide-carbon-silicon dioxide compound to high-temperature oxidation to remove interlayer carbon so as to obtain the nanometer titanium dioxide-silicon dioxide composite photocatalyst with the core shell structure. The invention also provides the nanometer titanium dioxide-silicon dioxide composite photocatalyst with the core shell structure prepared by using the method.

The invention relate to a nm material modified latex coating for inside wall with environmental protection,comprises of the following components:water 18-24,dispersant 0.4-1.0;nm silicon dioxide powder 1.0-3.0;deposit barium sulfate 20-30;talcum powder 10-15;titanium dioxide 10-20;antifoaming agent 0.1-0.2;modified crylic acid 25-35;zinc oxide and titanium oxide compound finishing mixture 0.1-0.3;thickener 0.3-0.4; 0.15-0.30;and pH regulator. The modified crylic acid has the lowest temperature to form film being 0-5deg.C and glassifying temperature being 10-15deg.C, the coating contains 6 organic compound lower than 5g / l,is suitable for decoration and protection for inside wall.

The invention belongs to the technical field of structural-color material preparation, and discloses an amorphous photonic crystal structure-color material with a photocatalytic effect and a preparation method thereof. The method comprises the following steps: preparing a monodisperse silicon dioxide microsphere emulsion by adopting an improved method, and modifying the surfaces of silicon dioxidemicrospheres with ammonia water; and then, preparing SiO2@TiO2 nano microspheres with uniform particle sizes by adopting a mixed solvent method, and carrying out heat treatment under argon to obtainthe amorphous photonic crystal structure-color material with a photocatalysis function. Through introduction of oxygen defects, the nano microspheres can exhibit the characteristics that the amorphousdisordered photonic crystal structure color is high in saturation and does not fade. The shell layer formed by TiO2 nanocrystalline has high electron-hole separation rate, and the photocatalysis function is improved. The non-angle-dependent amorphous photonic crystal structure-color material with the photocatalytic property can replace conventional pigment in use, has double functions of degrading pollutants, and has a great application prospect in environment protection development in pigment industry.

The invention relates to the technical field of magnetic nanocomposite materials, in particular to a molybdenum disulfide / ferroferric oxide magnetic nanocomposite material and a preparation method andapplication thereof. The molybdenum disulfide / ferroferric oxide magnetic nanocomposite material is of a flower type structure and is prepared by combining molybdenum disulfide and ferroferric oxide supported on the surface of molybdenum disulfide; and heterojunction is formed between molybdenum disulfide and ferroferric oxide. The photocatalytic degradation rate of organic pollutants for TC by the molybdenum disulfide / ferroferric oxide magnetic nanocomposite material is increased by 172.8% and 71.3% separately compared with a MoS2 material and a Fe3O4 material, and after recycling is performed for 5 times, the photodegradation rate of TC is only reduced by 3.5%. The test results show that the molybdenum disulfide / ferroferric oxide magnetic nanocomposite material is excellent in photocatalytic degradation effect on the organic pollutants and good in cycling stability.

The invention provides an amorphous photonic crystal schemochrome material based on black titanium dioxide and silicon dioxide composite and a preparation method of the amorphous photonic crystal schemochrome material. The material component comprises SiO2 amorphous photonic crystal and black TiO2, and the mass ratio of the black TiO2 and the SiO2 amorphous photonic crystal is 1 to (0.1-1). The preparation method comprises the steps that (1) black TiO2 nanoparticle powder is prepared, and SiO2 amorphous photonic crystal microsphere powder is prepared; (2) the black TiO2 / SiO2 materials are prepared, specifically, the SiO2 amorphous photonic crystal microsphere powder and the black TiO2 nanoparticle powder are dissolved in ethanol, ultrasonic dispersion is conducted after stirring, and theproduct is dried. According to the preparation method, the schemochrome is combined with the photocatalysis function, the limitation of preparing non-angle independent color material by absorbing coherent scattering light with carbon black as the back bottom is broken, and the obtained material has the function of photocatalytic degradation of pollutants at the same time.

The invention discloses a bismuth vanadate-franklinite composite photocatalyst, and a preparation method and application thereof. The photocatalyst comprises an m-BiVO4 substrate, wherein ZnFe2O4 is dispersed on the surface of the m-BiVO4 substrate, and a mass ratio of the ZnFe2O4 to the m-BiVO4 substrate is (5-20): (95-80). A monoclinic bismuth vanadate-franklinite composite photocatalysis material is prepared by using a low-temperature self-propagating sol-gel method and a calcination method; the photocatalytic properties of the prepared material are tested by using simulated visible light;and the superior photocatalytic properties of the material are proved by degradation of the non-biodegradable organic pollutant methylene orange. The material belongs to inorganic photocatalysis materials, and has high photocatalytic activity and good application prospects in environmental protection. The preparation method has the advantages of controllable morphology of monoclinic bismuth vanadate, good compounding between franklinite and monoclinic bismuth vanadate, uniform dispersion and formation of effective p-n heterojunctions.

The invention discloses a technology for recycling wastewater resulted from the production of aromatic polycarboxylic acid. Combined technology including filtering, photocatalytic oxidation and ion exchange resin is adopted to process the wastewater resulted from the production of aromatic polycarboxylic acid so that the wastewater can be recycled. The technology comprises that: suspending substances in the wastewater are removed by using a filter reactor in order to ensure that solid particles cause no impact to subsequent technologies, the completely-filtered wastewater enters a photocatalytic reactor, organic substances dissolved in the water are removed, the wastewater degraded by means of photocatalysis enters an ion exchange column, and metal ions in the water are removed. The technology can achieve the COD removal rate of discharged water reaching over 90%, the removal rate of PT acid reaching over 92% and the removal rate of metal ions reaching over 90%, and can greatly reduce the investment on equipment, floor area and running period.

The invention provides a preparation method of a visible light catalyst. The preparation method comprises the following steps: weighing tetrabutyl titanate, ethanol, hydrazine hydrate and AgNO3, dispersing the tetrabutyl titanate in the ethanol, adding N2H4.H2O, ultrasonically dispersing in icy water bath for 0.5 to 1.5 h, forming TiO2 precursor sol, transferring the TiO2 precursor sol into a hydrothermal kettle, adding AgNO3 into the hydrothermal kettle at an ultrasonic state, reacting for 6 to 10 h at 160 to 200 DEG C, and obtaining the anatase TiO2 / Ag visible light catalyst. Oxygen vacancyformed inside the TiO2 prepared by virtue of the reduction of N2H4.H2O is synergistic with Ag, so that the absorption spectral range of a sample is enlarged, the propagation rate and separation efficiency of photon-generated carrier can be improved, and the visible light catalytic efficiency can be increased. The oxygen vacancy is separately formed inside TiO2 and nano silver corresponding to thevisible light is carried on the surface of TiO2 by virtue of in-situ reduction reaction, and the preparation method is simple and easy to control.

The invention discloses a mesoporous photo-thermal catalyst for medium-high temperature methane dry reforming as well as a preparation method and application thereof. The preparation method belongs tothe field of solar photo-thermal conversion and photo-thermal catalyst preparation methods, and adopts an impregnation method to load a thermal catalyst Ni to the surface of a mesoporous TiO2 photocatalyst, so as to form the Ni-mesoporous TiO2 photo-thermal catalyst with nano Ni particles loaded on the surface of mesoporous TiO2. The medium-high temperature methane dry reforming photo-thermal synergistic catalyst provided by the invention is simple to prepare and easy to operate, has good photo-thermal synergistic catalytic activity at 400-600 DEG C, and has obviously improved activity compared with the traditional Ni-based thermal catalyst, so that the catalyst has higher industrial application level and prospect.

The invention discloses a photoelectrochemical aptamer sensor and a preparation method and application thereof. The sensor comprises a working electrode, the reaction end face of which is modified with a composite film, wherein the composite film is composed of a graphite phase carbon nitride nanosheet composite material jointly modified by gold nanoparticles / cerium dioxide quantum dots; and a specific aptamer probe is self-assembled on the surface of the composite film. The preparation method comprises the following steps: modification of CeO2QDs / Au / g-C3N4 and fixation of the specific aptamer probe. The photoelectrochemical aptamer sensor disclosed by the invention has the advantages of high stability, long service life, strong anti-interference capability, wide detection range, low detection limit and the like, can realize specific detection of target objects in media such as water bodies and organisms, and is high in utilization rate, high in use value and good in application prospect. The preparation method of the sensor has the advantages of simple process, convenience in operation, safety, low cost, no pollution, high manufacturing efficiency and the like, is suitable for large-scale preparation and is beneficial to industrial application.

The invention relates to a method for synthesizing samarium doped titanium dioxide powder by a phonochemistry-microwave hydrothermal two-step process, which comprises the following steps of: firstly, slowly adding analytically pure butyl titanate into anhydrous alcohol to obtain a solution A, uniformly mixing analytically pure deionized water with the anhydrous alcohole, and then dissolving analytically pure samaric chloride into the solution A to obtain a solution B; adding analytically pure glacial acetic acid the solution B to obtain a solution C; uniformly mixing the solution A with the solution C and placing in an ultrasonic wave generator to perform ultrasonic reaction, and then naturally cooling to the room temperature to obtain a solution D; pouring the solution D into a hydrothermal reaction kettle, sealing the hydrothermal reaction kettle is sealed, placing in a microwave hydrothermal reaction instrument, and naturally cooling to the room temperature after reaction; opening the hydrothermal reaction kettle, centrifugally collecting and washing and drying the product to obtain the final product of the samarium doped titanium dioxide powder. The invention has the simple technological equipment; and compared with the titanium dioxide powder, the prepared powder has obvious capability for catalyzing the organic matters to degrade after being irradiated under visible lights.

The invention discloses a preparation method of zinc oxide-active carbon composite catalysts. The method comprises the following steps of (1) active carbon pretreatment: soaking the active carbon withan inorganic acid solution for 12 to 24 h; performing filtering; washing the materials to a neutral state by deionized water; performing soaking for 12 to 24 h with an inorganic basic solution; performing filtering; washing the materials to a neutral state by deionized water; performing drying; obtaining the pretreated active carbon; (2) adding the pretreated active carbon into the deionized water; performing ultrasonic dispersion for 6 to 8 h, thus obtaining an active carbon suspension; (3) adding a carbonate solution into the active carbon suspension; performing stirring for 15 to 30 min; then, adding a zinc salt solution; performing stirring for 3 to 5 h; performing suction filtering and drying; performing roasting for 1 to 2 h at the temperature of 280 to 400 DEG C to obtain the zincoxide-active carbon composite catalysts. The zinc oxide-active carbon composite catalysts have good photocatalysis effects; good application prospects are realized in aspects of industrial waste waterand waste gas treatment.

The invention provides an adsorption / flocculation / photocatalysis composite dye wastewater treatment agent and a wastewater treatment method, and relates to the technical field of wastewater treatment.The adsorption / flocculation / photocatalysis composite dye wastewater treatment agent is prepared from the following raw materials (by weight): 0.1-0.5 part f cerium and gadolinium codoped nano-TiO2, 60-80 parts of PDMDAAC modified diatomite and 20-35 parts of an inorganic polymer flocculant. By combining adsorption, flocculation and photocatalysis and selecting appropriate raw materials, the prepared wastewater treatment agent has excellent treatment effect on dye wastewater, and has high decolorization rate, high COD removal rate and good degradation effect.

The invention discloses a titanium dioxide nano-particles repairing nanowires heterojunction composite material, which adopts a hydrothermal method to prepare anatase type titanium dioxide nanowires firstly, then the anatase type titanium dioxide nanowires are added into hydrothermal reaction of titanium oxide nanoparticulates, and are used as a base body, the titanium oxide nanoparticulates grow on the anatase type titanium dioxide nanowires by using a mode of an epitaxial growth mode, and an heterojunction composite material with excellent photocatalytic performance is obtained by controlling mass ratio of nanowires to nanoparticulates. Compared with existing titanium dioxide materials, the titanium dioxide nano-particles repairing nanowires heterojunction composite material has excellent photocatalytic performance, and has excellent application prospect in the field of photocatalytic treatment organic pollutants.

The invention discloses a titanium dioxide nanowire and a preparation method thereof. The preparation method comprises the following process: (1) a titanium source and an organic reagent are mixed andsubjected to a hydrothermal reaction under the action of alkali, and nano titanium salt is obtained; (2) the nano titanium salt reacts with acid, and an intermediate product is obtained; (3) the intermediate product is calcined and the titanium dioxide nanowire is obtained. Titanium dioxide in the nanowire form can be obtained, the production efficiency is high, and the production cost is low.

The present invention provides a method for immobilization of titanium dioxide and application of the titanium dioxide, the method for immobilization of the titanium dioxide comprises the following steps: silica sol and a silane coupling agent are mixed evenly, adding titanium dioxide evenly, the quality of the two silicon oxide and titanium dioxide in silica sol ratio (0.6-2): 1; adding dispersant, mixing and stirring to obtain mixture, the mixture is sprayed carrier Aluminum Alloy online the pre treated, 150 to 170 DEG C under the condition of dry 0.5-5h, TiO2 catalyst supported by silica sol. The technical scheme of the invention, improves the catalyst supported firmness compared with the prior art, the photocatalytic effect of catalyst supported on the technical scheme of the invention has better, and the problem of cracks on the catalyst surface is solved.

The invention relates to a method for preparing a titanium dioxide nanotube / cotton fabric photocatalytic material based on click chemistry. The method includes the synthesis of pretreated cotton fabrics, the synthesis of reduced cotton fabrics, the synthesis of bromo-dopamine hydrochloride, the synthesis of bromo-titanium dioxide nanotubes and the synthesis of the titanium dioxide nanotube / cottonfabric photocatalytic material based on click chemistry. The method is simple, low in cost, middle in conditions, high in product yield, less in side reaction and environmentally friendly. The prepared titanium dioxide nanotube / cotton fabric photocatalytic material based on click chemistry is high in adsorption efficiency and good in stability, has good photocatalytic effect and excellent environmental friendliness, and can be used to treat dyes in printing and dyeing wastewater and expand the application of the cotton fabrics in the photocatalytic adsorption of dye wastewater.

The invention discloses low VOC sponge which comprises the following components: grafted polyether polyol, a highly active polyether polyol, a catalyst, a foam stabilizer, a chain extender, a foamingagent, a flame retardant, RGO / TiO2 nanoparticles, and diphenylmethane diisocyanate. A preparation method comprises the steps: preparing the RGO / TiO2 nanoparticles, preparing finished sponge, preparinga composite fabric, embossing and solarizing. The low VOC sponge is applied to automotive trim. The process is simple, and the VOC content in the composite fabric can be effectively reduced; RGO / TiO2is used as a photoelectron catalyst and does not participate in a chemical reaction, so that a good recyclable catalytic effect is achieved, and the problem of subsequent VOC release of the polyurethane sponge can be continuously and effectively solved; the sponge prepared by the invention is applied to embossing, the embossing forming effect is good, and the pattern appearance is uniform; the problem that a traditional half-ether half-ester polyurethane sponge is uneven in hardness is solved, and the application prospect is wide.

The invention relates to a method for preparing a zinc oxide photocatalytic nanomaterial by a template-free method. According to the low-cost template-free method, raw materials include water, ethanol, zinc nitrate and n-butylamine, wherein zinc nitrate is a zinc source, water and ethanol serve as solvents, and n-butylamine is an alkali source, and a simple hydro-thermal synthesis method is carried out to finally obtain the zinc oxide nanomaterial with a unique spherical structure with coarse surface by adopting. Shown in XRD (X-Ray Diffraction) spectrogram, the prepared zinc oxide material has a typical wurtzite structure and is good in crystallization. The photocatalytic test results show that the prepared zinc oxide material has excellent photocatalytic performance, can effectively solve the problems of environmental pollution and the like, and further has a potential application prospect in the fields of energy sources, biomedicines and the like.

The invention discloses a gold nanoparticle / cerium dioxide quantum dot co-modified graphite phase carbon nitride nanosheet composite material as well as a preparation method and application thereof. The composite material comprises a cerium dioxide quantum dot loaded graphite phase carbon nitride nanosheet and gold nanoparticles modified on the cerium dioxide quantum dot loaded graphite phase carbon nitride nanosheet, the graphite-phase carbon nitride nanosheet loaded with the cerium dioxide quantum dots takes a graphite-phase carbon nitride nanosheet as a carrier, and the cerium dioxide quantum dots are loaded on the graphite-phase carbon nitride nanosheet. The preparation method comprises the step of modifying the gold nanoparticles on the carrier. The composite material disclosed by the invention has the advantages of strong photoelectric capability, high light energy utilization rate, good dispersion performance, high stability and the like, can be widely used for detecting and degrading pollutants in the environment as a functional material, and has very high use value and application prospect. The preparation method of the composite material has the advantages of being simple in process, convenient to operate, low in cost, free of additional chemical auxiliary solvents and the like, is suitable for large-scale preparation and is beneficial to industrial application.

The invention discloses a preparation method of MoS2 quantum dot loaded nano TiO2, which applies chitosan to the reaction of nano titanium dioxide and molybdenum disulfide, so that the prepared MoS2@TiO2 nano material keeps good in-situ dispersion characteristic, and the catalytic efficiency of titanium dioxide in natural light is improved. According to the method disclosed by the invention, a MoS2 lamella is opened by using high-frequency and high-energy ultrasonic treatment, and MoS2 can be crushed at 110-140 DEG C, so that MoS2 small molecules subjected to fault crushing can be doped into nano titanium dioxide crystals. The preparation method of the MoS2 quantum dot loaded nano TiO2 is simple and convenient to operate, easy to implement, short in consumed time, low in consumption, low in cost, high in yield, good in repeatability and suitable for large-scale production or does not cause secondary pollution to the environment.

The invention discloses a preparation method for a nanometer platinum viscose fiber. The preparation method comprises the following steps of: carrying out pre-processing: firstly, carrying out acid pickling on nanometer platinum micro-particles, and then, washing the nanometer platinum micro-particles by potassium hydroxide alkaline liquor until the platinum micro-particles are neutral; (2) carrying out surface processing: adding the nanometer platinum micro-particles into ethyl alcohol or water, carrying out ultrasonic dispersion, and then, adding a coupling agent; (3) compounding a loading system: evenly dispersing the nanometer platinum micro-particles subjected to the surface processing and an inert carrier in an ethyl alcohol and ethylene glycol mixed solution, carrying out ultrasonicdispersion, and under a high-speed stirring condition, loading the platinum micro-particles to the surface of the inert carrier by a microwave heating method to obtain the loaded platinum micro-particles; (4) blending the loaded nanometer platinum micro-particles and a viscose spinning solution, and carrying out spinning by a two-bath method, so as to obtain a mixed fiber; and (5) carrying out steam processing: processing the mixed fiber by steam for 10-30 min, then, carrying out high-pressure steaming for 10-20 min, and finally, carrying out drying.

The invention relates to a preparation method of a hydrophilic anatase-phase titanium dioxide nano photocatalyst. The preparation method comprises the following steps: (S1) preparing mixed liquid of ethanol and titanium tetrachloride at room temperature; performing an alcohol thermal reaction of the mixed liquid in an oven; after the reaction, cooling to room temperature to obtain white precipitate with supernatant; (S2) pouring the supernatant in the step (S1), adding ethanol into the white precipitate and centrifuging; repeatedly cleaningto obtain white precipitate; (S3) adding deionized water into the white precipitate obtained in the step (S2), and performing freeze drying to obtain a white powdery hydrophilic anatase-phase titanium dioxide nano photocatalyst. With a size of only about10nm, the photocatalyst prepared in the invention has the advantages of small size, large specific surface area, and has strong redox ability and good photocatalysis effect under the impact of surface effect, small size effect and quantum size effect.

The invention discloses a preparation method of highly-catalytic type nanometer cerium oxide, and belongs to the technical field of preparation of nanometer-grade cerium oxide. The preparation method comprises the steps of preparing a certain amount of cerium acetate solution and ammonium hydroxide under the same closed environment; heating for 30 to 40min with low-power microwave to enable ammonia to volatilize and fill the whole closed container and synchronously enable part of ammonia to be diffused into a cerium solution through a liquid gas interface to slowly react so as to obtain a precipitate; then washing, centrifugally drying and firing for 5 hours under a temperature of 500 DEG C to obtain the highly-catalytic type nanometer cerium oxide. According to the preparation method of the highly-catalytic type nanometer cerium oxide, the cost can be effectively decreased, and the prepared nanometer cerium oxide particles are 5 to 10nm in particle size; the novel microwave interface technology is performed, which avoids the limitation due to the high requirements of the general method on temperature and environment; meanwhile, the nanometer cerium oxide has an outstanding photocatalysis effect and can be applied to the fields of degradation of indoor formaldehyde, purification of air in a car, etc.

The invention discloses a molybdenum sulfide nano-sheet / titanium dioxide nano-sheet / graphite fiber composite material and a method for preparing the same. The molybdenum sulfide nano-sheet / titanium dioxide nano-sheet / graphite fiber composite material and the method have the advantages that visible light photocatalytic effects of titanium dioxide nano-sheets can be enhanced by three-dimensional heterogeneous structures formed by two-dimensional molybdenum sulfide nano-sheets, two-dimensional titanium dioxide nano-sheets and one-dimensional graphite fibers, excellent photocatalytic effects can be realized by the molybdenum sulfide nano-sheet / titanium dioxide nano-sheet / graphite fiber composite material in ultraviolet light and visible light, accordingly, the sunlight utilization ranges can be expanded, and photocatalytic effects can be improved; the molybdenum sulfide nano-sheet / titanium dioxide nano-sheet / graphite fiber composite material is high in methyl orange photocatalytic efficiency in the ultraviolet light and the visible light, and accordingly the sunlight utilization rate can be effectively increased; operation procedures are simple, the molybdenum sulfide nano-sheet / titanium dioxide nano-sheet / graphite fiber composite material and the method are low in production cost and easy to popularize, and application of titanium dioxide in actual photocatalytic fields can be greatly promoted.

The invention discloses a solar photocatalytic glass. The solar photocatalytic glass is of an AgX @ Ag surface structure and has photocatalytic performance under sunlight irradiation. Halogen-containing boron aluminum silicate glass is prepared by an ordinary high-temperature melting technique, and then subjected to ion exchange heat treatment, the prepared glass is of the AgX @ Ag surface structure, can catalyze and decompose organic matters and has good photocatalytic performance, therefore, a solid foundation is laid for a further research of preparation technologies of glass with photocatalytic performance under sunlight irradiation, and new ideas and methods are provided for allowing the glass to exhibit photocatalytic performance.

The invention discloses a BiZn hydrotalcite photocatalyst, and a preparation method and application thereof. The photocatalyst is two-dimensional ultra-thin BiZn nanosheets having a thickness of 5-10nm. The method includes (1) mixing a surfactant, ethylene glycol and water, then adding n-butanol, and stirring the solution until the solution is transparent; (2) adding a zinc salt and a bismuth salt, stirring the mixture, then adding thiourea or urea to obtain a mixture solution, and heating the solution for reaction; and (3) after heating is finished, performing cooling, filtration and dryingto obtain the BiZn hydrotalcite photocatalyst. The photocatalyst can be used for catalyzing xylose conversion to prepare xylonic acid. The method has advantages of low reaction condition requirements,low raw material costs, simple and feasible synthesis, and a reduced production cost so that the method has an industrial production potential. A photocatalytic reaction system different from the traditional thermal catalytic processes is energy-saving, safe and environmentally friendly.

The invention discloses a method for degrading contaminants in a water body by using a nanometer photocatalyst flocculate. The method comprises the following steps: firstly, adding a nanometer photocatalyst into water for uniformly dispersing; then adding a coagulant, stirring and finishing coagulating, wherein the nanometer photocatalyst flocculate is formed in the coagulating process, a nanometer photocatalyst is nano-nitrogen-doped titanium dioxide (N-TiO2) and the coagulant is polyaluminum ferric chloride (PAFC); secondly, after the coagulating is finished, separating the generated flocculate to obtain the nanometer photocatalyst flocculate; thirdly, adding the nanometer photocatalyst flocculate obtained in the second step into to-be-treated wastewater and putting the wastewater undervisible light for irradiating and finishing photocatalytic degradation of the contaminants in the wastewater. The nanometer photocatalyst is prepared into the flocculate and can be separated from a water body by adopting simple centrifugal separation steps. The prepared flocculate can be uniformly dispersed in a to-be-treated water body and is matched with the visible light for irradiating, so that the treatment efficiency and treatment effects of the wastewater are improved.