131 results about "Bismuth oxybromide" patented technology

The invention discloses a flaky titanium dioxide / bismuth oxybromide composite photocatalyst and a preparation method thereof. The composite photocatalyst is a heterogeneous composite material formed by depositing bismuth oxybromide on a titanium dioxide nanometer sheet. The preparation method comprises the following steps: dispersing the titanium dioxide nanometer sheet, thioglycollic acid, potassium bromide in deionized water in an ultrasonic manner, uniformly mixing to obtain a solution, and dissolving bismuth nitrate in ethylene glycol to obtain a solution; mixing the two solutions obtained in the former step to obtain a milky emulsion, stirring, leaving the emulsion to stand, and performing centrifugal separation and washing to obtain the composite photocatalyst. In the preparation process, through adjusting ratio of titanium dioxide to bismuth oxybromide, composite structures in different particle diameters can be obtained. The composite photocatalyst is simple in preparation technology; particularly, through thioglycollic acid, bismuth oxybromide can be uniformly distributed on the titanium dioxide (TiO2) sheet; the composite photocatalyst shows a more excellent photocatalytic activity compared with that of the titanium dioxide nanometer sheet under visible light, and has the potential practical application prospect of photocatalytic degration of organic pollutants through solar power light in the processing technology.

A preparation method of bismuth oxybromide with high-efficient visible light activities adopts cetyl pyridine bromide as raw material, the surfactant has the functions of providing bromine source and structure template agent simultaneously, and the bismuth oxybromide with stable structure and performance and high activity can be obtained. Dilute nitric acid solution dissolved with Bi(NO3)3 is dripped into the cetyl pyridine bromide solution to produce faint yellow precipitate, and then the pH value needs to be adjusted to 7; and the mass ratio of the two raw materials meets nBi: nBr=1: 1.5. The bismuth oxybromide synthesized by the method is faint yellow solid powder and has no special smell. The bismuth oxybromide has quadrangular crystal form detected by an instrument, the specific surface area is large, the surface aperture is small, the band gap is 2.62eV, the crystallinity is 98.3% of layer crystal, the product purity is more than 99.9%, the visible light activity of the prepared bismuth oxybromide is high, and various organic dyes and microcystic toxins can be degraded effectively in a short time.

The invention discloses bismuth oxybromide particles with a three-dimensional flower-like microstructure and a preparation method and use thereof, which belong to the technical field of visible-light catalyst. The bismuth oxybromide powder has a three-dimensional flower-like microstructure of which the diameter is 1 to 5 micrometers, and the specific surface area of the bismuth oxybromide powder is 11.2 to 27.9m<2> / g. In the preparation method, mixed solution of glycol and isopropanol is used as a solvent, a bismuth salt and hexadecyl trimethyl ammonium bromide are used as a bismuth source and a bromide source respectively, the bismuth salt and hexadecyl trimethyl ammonium bromide are dissolved in the mixed solution of the glycol and isopropanol according to a Bi to Br ratio ranging from 1:1 to 1:4, the mixed solution is filled in a closed reaction kettle, the reaction kettle is placed in an oven at 120 to 160 DEG C for reaction for 6 to 24 hours, the obtained product is washed, centrifuged, dried and roasted in a muffle furnace at 250 to 450 DEG C for 4 to 6 hours, and finally the bismuth oxybromide is obtained. The obtained product has high photocatalyzing performance. The method is simple and convenient, the period is short, the raw materials are readily available, and the method meets the requirements for batch production.

The invention discloses a solar nitrogen fixation pholocatalyst. The solar nitrogen fixation pholocatalyst is hydrogenated bismuth oxybromide, has the molecular formula of H-BiOBr, is used for solar nitrogen fixation photocatalysis, and is used for a solar nitrogen fixation photocatalytic reaction in which water is used as a reducing agent. The preparation method of the catalyst comprises steps of1, taking an ethylene glycol, isopropanol or propanetriol solution; 2, adding a bismuth-containing compound and a bromine-containing compound into the alcoholic solution, mixing and sufficiently agitating; 3, agitating until a clear solution, then adding a neutral solution, agitating, then loading in a reaction kettle, and carrying out a thermostatic reaction; 4, cooling to a room temperature, carrying out centrifugal separation, washing for multiple times by using water and an ethanol solution, drying, and then grinding into powder; 5, incinerating in a hydrogen atmosphere, so as to obtain the hydrogenated bismuth oxybromide. The hydrogenated bismuth oxybromide pholocatalyst obtained by the method provided by the invention is green and nontoxic and is low in price; raw materials are simple and wide in source; the method is easy to operate and moreover, the solar nitrogen fixation pholocatalyst can be massively prepared within a short time and has favorable solar nitrogen fixation photocatalytic performance.

The invention discloses a method for preparing a bismuth-enriched bismuth oxybromide photocatalyst and belongs to the field of photocatalysis. The method is mainly characterized in that heavy doping of bismuth oxybromide can be realized under actions of a certain pH value and polymer guide, and a novel bismuth-enriched bismuth oxybromide Bi4O5Br2 photocatalytic material is obtained and has excellent visible-light catalytic activity. The method comprises the following preparation steps: mixing glycerin and deionized water into a beaker according to a certain ratio, adding bismuth nitrate pentahydrate, adding a bromine source while stirring to be clarified and transparent, fully stirring, adding a polymer guide agent, and regulating the pH value of the solution with a sodium hydroxide solution; continuously stirring until uniform white suspension is formed, transferring the suspension into a high-pressure reactor, reacting at a high temperature for a certain time, performing centrifugalseparation on the obtained product, washing for several times, and drying, thereby obtaining the bismuth-enriched bismuth oxybromide Bi4O5Br2 photocatalyst. The method is simple in process, low in cost and easy to operate and realize, and the prepared bismuth-enriched bismuth oxybromide Bi4O5Br2 photocatalyst has high visible-light catalytic activity and is expected to be applied to degradation ofenvironmental pollutants.

The invention discloses a visible-light response photocatalyst, namely bismuth hydride deposited bismuth oxybromide with the molecular formula of H-Bi@BiOBr for visible-light photocatalysis degradation of organic matter in the water body. The preparation method of the catalyst comprises the following steps: 1, organic alcohol is taken as a solvent; 2, a bismuth salt compound and a bromine salt compound are added into the organic alcohol solvent, mixed and fully stirred; 3, after the solution is stirred to be clear, a neutral solution and a certain quantity of reducing agents are added, stirring is carried out, and then the solution is put into a reaction kettle to conduct a thermostatic reaction; 4, the solution is cooled to a room temperature, subjected to centrifugal separation and washed with water and an ethanol solution for multiple times, and a powder is collected after drying; and 5, calcination is carried out in a hydrogen atmosphere, and the bismuth hydride deposited bismuth oxybromide is obtained. The bismuth hydride deposited bismuth oxybromide photocatalyst obtained through the preparation method is environmentally friendly, harmless, material sources are widely available, the price is low, the method is controllable and easy to operate, and the photocatalyst can be mass produced and has good photocatalysis performance on degradation of the organic matter.

The invention relates to a method for preparing a hierarchical structure bismuth oxybromide hollow microsphere photocatalysis material, comprising the steps of: respectively dissolving bismuth nitrate and brominated 1-cetyl-3-methylimidazole methylimidazole in ethylene glycol monobutyl ether, mixing the two solutions, and placing the mixed solution in an enclosed autoclave to react at the temperature of 140-180 DEG C for 0.5-12 hours. The preparation method provided by the invention can be carried out under the hydro-thermal condition, has advantages of low cost as well as simple and maneuverable equipment, can be applied in batch production, and has an important potential application value in industrial production. The prepared hierarchical structure bismuth oxybromide hollow microspherephotocatalysis material can markedly improve the separation of photocarrier and has high photocatalysis performance.

The invention discloses a surface oxygen vacancy-modified bismuth oxybromide photocatalyst and a preparation method thereof. The invention relates to the technical field of photocatalysis. According to the invention, a bismuth oxybromide material is prepared through a chemical precipitation method, and the bismuth oxybromide material comprises BiOBr or Bi24O31Br10. Then, bismuth oxybromide powderis dispersed in a methanol-water solution, and nitrogen aeration treatment and visible light illumination are carried out, so that to the surface oxygen vacancy-modified bismuth oxybromide photocatalyst is obtained. The preparation method of the oxygen vacancy-modified bismuth oxybromide photocatalyst is simple, is easy to operate, and is high in repeatability and low in cost, and the absorption rate of visible light can be remarkably improved.

The invention discloses a black bismuth oxybromide photocatalyst and a preparation method thereof, belonging to the field of photocatalysis. The black bismuth oxybromide photocatalyst is mainly characterized in that black bismuth oxybromide is high in absorption on visible light, and by oxygen deficiency, separation of photoproduction electron-hole is easy, so that the catalyst is high and efficient in photocatalysis capability. The preparation method comprises preparation steps of 1. preparing white bismuth oxybromide solids by a solvothermal method; and 2. putting a certain amount of the prepared white bismuth oxybromide sample into a tubular furnace, vacuumizing the tubular furnace, feeding high-purity inert gas, performing high-temperature treatment for 3-8 hours to obtain a black bismuth oxybromide sample. The method is simple and is easy to operate; the obtained black bismuth oxybromide photocatalyst is high in visible light catalyst performance.

The invention discloses a photocatalyst, and more specifically discloses nanometer carbon fiber supported bismuth oxybromide bismuth oxyiodide with the molecular formula BiOI / BiOBr / CNFs. The nanometercarbon fiber supported bismuth oxybromide bismuth oxyiodide is used for high efficiency solar energy nitrogen fixation. A preparation method comprises following steps: 1, an organic solution is takenas a solvent; 2, an organic matter with a molecular weight larger than 5000 is dissolved in the organic solvent so as to obtain a mixed solution; 3, electrostatic spinning is adopted for spinning; 4,fiber carbonization is carried out so as to obtain nanometer carbon fiber; 5, an organic alcohol is taken as a solvent; 6, a bismuth salt compound, a bromine salt compound, and an iodine salt compound are added into the organic alcohol solvent for mixing and full stirring; 7, the nanometer carbon fiber is added, and ultrasonic treatment is carried out; 8, an obtained product is introduced into areaction vessel for constant temperature reaction; and 9, an obtained reaction product is cooled to room temperature for centrifugation, respective washing with water and an alcohol solution is carried out, drying is carried out, an obtained powder is collected so as to obtain the nanometer carbon fiber supported bismuth oxybromide bismuth oxyiodide. The catalyst prepared using the preparation method is friendly to the environment, is nontoxic, is low in cost, and possesses high efficiency solar energy nitrogen fixation performance; and batch production can be realized.

The invention discloses a bismuth-bismuth tungstate-bismuth oxybromide ternary compound and a preparation method and application thereof. The method comprises the following steps of: adding bismuth nitrate into ethylene glycol, and uniformly stirring to obtain a solution A; adding sodium tungstate and potassium bromide into ethylene glycol, and uniformly stirring to obtain a solution B; dripping the solution B into the solution A, and uniformly stirring to obtain a mixed solution; and transferring the mixed solution to a hydrothermal kettle for solvothermal reaction, wherein the molar ratio of bismuth nitrate, sodium tungstate and potassium bromide in the mixed solution is 2: 1: (0.5-5). The Bi / Bi2WO6 / BiOBr ternary compound with nano structure prepared by the method has strong adsorption and visible light degradation effects on cationic dye rose red B in water.

The invention belongs to the technical field of preparation of composite materials and discloses a ferric oxide / bismuth oxybromide composite material and a preparation method and application thereof. The ferric oxide / bismuth oxybromide composite material is formed by ferric oxide nano-clusters depositing on the surfaces of bismuth oxybromide nano-sheets. The preparation method comprises the steps of adding an alkali solution into a ferric nitrate solution to obtain a ferric hydroxide colloidal solution, adding a KBr solution into a bismuth nitrate solution, performing mixing to obtain a mixed solution, dropwise adding the ferric hydroxide colloidal solution into the mixed solution and performing hydrothermal reaction to obtain the ferric oxide / bismuth oxybromide composite material. The preparation method has the advantages of being simple in preparation process and low in cost, having very good environmental protection benefits and the like, the prepared composite material has excellent photocatalytic performance and is widely applied to the field of photocatalytic degradation of dye wastewater, and the higher catalytic efficiency can be obtained.

The invention discloses a preparation method of a Co-BiOBr (cobalt-bismuth oxybromide) / TiO2 (titanium dioxide) / GO (graphene oxide) ternary composite photocatalyst, and belongs to the technical field of photocatalysis. The preparation method comprises the following steps of (1) preparing a BiOBr photocatalyst doped with Co<2+>; (2) preparing a Co-BiOBr / TiO2 binary composite photocatalyst; (3) preparing the Co-BiOBr / TiO2 / GO ternary composite photocatalyst. The preparation method has the advantages that by doping the Co<2+> and compounding with the TiO2 to form a heterojunction, the photo-induced electron can be quickly moved through the good conductivity of GO, and the charge compounding is inhibited; by utilizing the larger specific surface area of GO, the adsorbing ability of the photocatalyst is improved, and a dye is favorably degraded; the degrading rate on Rhodamine B can reach 96.8% within 20min by the prepared modified Co-BiOBr / TiO2 / GO ternary composite photocatalyst; the improved solvent thermal method and ultrasonic method are simpler and more convenient, and the reaction condition is milder; compared with the method of depositing noble metal on the BiOBr surface, the obtaining of the raw materials in the preparation method is simple, the cost is lower, the preparation method is suitable for the treatment of large-scale printing-dyeing wastewater, and the practicality is good.

The invention provides a preparation method and application of an AgI / BiOBr heterojunction photocatalyst. The method comprises the following steps that firstly, a bismuth salt substance and a brominesource substance are dissolved in ethylene glycol respectively, and the two solutions are mixed and are stirred for 1 h; a mixed solution is transferred into a reaction kettle and reacts at 125-185 DEG C for 14-22 h so as to obtain a milk white solid; the milk white solid is washed, dried and ground so as to obtain dried BiOBr powder; silver salt is dissolved in 40 ml of deionized water, the prepared BiOBr powder is added into the solution, an iodine source is dropwise added into the solution, and stirring is carried out for 60 minutes so as to obtain a yellow precipitate; and the yellow precipitate is washed, dried and ground, and obtained yellow powder is the AgI / BiOBr heterojunction photocatalyst. The AgI / BiOBr heterojunction photocatalyst prepared through the method is used for degrading organic pollutants in water; and compared with photocatalysts such as commercial TiO2 (P25), pure-phase AgI and pure-phase BiOBr, the photocatalyst has higher visible-light catalytic activity.

The invention discloses a bismuth-oxybromide-cadmium sulfide nano composite photocatalyst and a preparation method thereof and relates to the technical field of photocatalyst material preparation. The preparation method includes: utilizing cetyl trimethyl ammonium bromide and cadmium sulfide for reaction to obtain a bismuth-oxybromide nanosheet; allowing reaction on the bismuth-oxybromide nanosheet to generate cadmium sulfide nano crystals. Microstructure of the composite photocatalyst is characterized in that the cadmium sulfide nano crystals uniformly grow on the surface of the bismuth-oxybromide nanosheet which mainly presents a square structure, the cadmium sulfide nano crystals growing on the bismuth-oxybromide nanosheet are quantum dots, and particle size is 1-5nm. The bismuth-oxybromide-cadmium sulfide nano composite photocatalyst has high visible light catalytic activity, can remarkably increase degradation rate of organic dye and is expected to be used for organic pollutants in sunlight degraded water. The preparation method is simple in process equipment, simple and convenient to operate, high repeatability, low-in-cost and easy-to-get in raw material and suitable for industrial production.

The invention discloses a preparation method capable of controlling oriented growth of bismuth oxybromide photocatalysts and belongs to the field of photocatalysis. The preparation method is mainly characterized in that bismuth salt, bromide, glacial acetic acid and polyvinylpyrrolidone (PVP) are taken as raw materials, the added amounts of glacial acetic acid and PVP are controlled, the bismuth oxybromide photocatalysts with different growth orientations are obtained by virtue of a simple hydrothermal method, and photocatalytic performance of the bismuth oxide bromide photocatalysts are compared. The preparation method is simple in technology and low in cost, and the prepared bismuth oxybromide photocatalysts with different growth orientations have different visible light catalytic activities.

The invention discloses a preparation method of a Bi24Br10O31 visible-light-induced photocatalyst. According to the preparation method, ethylene glycol and glucose are used as a complexing agent and areductant, and a two-step method which combines microwave treatment and calcination is adopted; by the preparation method, operation is easy, large-scale production is easy, the obtained nanometer flower-like Bi24Br10O31 visible-light-induced photocatalyst is high in purity and high in degree of crystallinity, has high photogenerated carrier separation efficiency, high visible-light catalytic activity and high stability and can convert benzyl alcohol into benzaldehyde with high selectivity, and after a reaction for 2.5 hours, the conversion rate and the selectivity are as high as 99%; the preparation method has a very wide application prospect.

The invention discloses a preparation method and applications of a bismuth oxybromide compounded titanium dioxide nano-tube heterojunction material. According to the preset invention, a heterojunctionis constructed by modifying TiO2 so as to increase the visible light utilization efficiency and the photogenerated electron hole recombination efficiency, and organic dyes are photoelectrocatalytically removed from water so as to purify the water; the composite material grows on the titanium (Ti) sheet, and the photocatalytic effect can be used as the catalyst for degrading toxic substances in the dye wastewater, such that the catalyst is easily recovered after the removal of the organic dyes from the water body compared with the powder catalyst; the material has suitable forbidden band width, and can absorb visible light, promote the rapid transfer of photogenerated electron holes, and reduce the recombination of electron holes so as to further improve the photocatalytic efficiency; andby using the material as the catalyst, the rhodamine B dye degrading performance is obviously improved, the stability is good, and the material can be used for a long time.

The invention discloses a preparation method of a three-dimensional-structure bismuth oxychloride @ bismuth oxybromide composite ultrathin nanosheet and belongs to the technical field of synthesis ofphotocatalytic materials. The preparation method includes: dissolving bismuth nitrate pentahydrate and sodium dodecyl benzene sulfonate into a mannitol solution, stirring at room temperature till complete dissolution, taking and slowly adding a saturated sodium chloride solution into the above solution, and continuing stirring to obtain a white turbid solution; transferring an obtained solution into a hydrothermal reaction kettle for reaction to obtain a product-an ultrathin bismuth oxychloride nanosheet; taking and dispersing the ultrathin bismuth oxychloride three-dimensional nanosheet intoa saturated potassium bromide solution, and forming the three-dimensional-structure bismuth oxychloride @ bismuth oxybromide composite ultrathin nanosheet through high-temperature ion exchange. The preparation method is simple and easy-to-implement in operation process, and a synthetic bismuth oxychloride / bismuth oxybromide composite material has a three-dimensional structure formed by self-assembly of ultrathin two-dimensional nanosheets and is large in specific surface area and stable in structure.

The invention discloses a bismuth oxybromide and nano zinc stannate heterojunction and a preparation method thereof. The heterojunction is nano powder of which the chemical formula structure is Zn2SnO4 / BiOBr, and the particle size of the heterojunction is 20-30nm. The preparation method comprises the following steps: preparing a solution A, preparing a solution B, preparing a solvent heat product, preparing Zn2SnO4 nano powder, preparing a suspension C, and preparing the Zn2SnO4 / BiOBr nano powder. The nano Zn2SnO4 / BiOBr heterojunction is synchronized by using a two-step method, the operation is convenient to implement, and a product prepared through synchronization reaction is high in purity, and is excellent in photocatalytic performance under a visible light condition.

The invention discloses a hydrothermal preparation method for a small-size bismuth oxychloride / bismuth oxybromide chip. The method comprises the following steps: hydrolyzing bismuth ions in the presence of chloride ions and bromide ions so as to form a bismuth oxychloride / bismuth oxybromide crystal nucleus; controlling heating time and temperature and a template in an enclosed container so as to form a bismuth oxychloride / bismuth oxybromide chip with a controllable size; and carrying out cooling, cleaning and drying so as to obtain a high-purity bismuth oxychloride chip having a controllable size and directly grown on a substrate. The method provided by the invention adopts the principle of direct hydrolysis of bismuth chloride, only has one reactant, is simple in process flow and low in cost, can control the size of the produced chip by changing heating time and temperature and the template, and is a preparation method with commercial utilization value. The prepared bismuth oxychloride chip is extensively applied to the fields of photocatalysts and devices thereof.

The invention discloses a method for photoelectrochemically detecting an organophosphorus pesticide based on a BiOBr / Bi2S3 semiconductor heterojunction generated by biological induction. The method comprises the following steps: mixing malathion with avidin-modified magnetic beads, biotin-modified auxiliary DNA and a malathion aptamer, incubating, removing part of the malathion aptamer by using malathion to recover the single strand of the auxiliary DNA, triggering by using the auxiliary DNA to form G-rich dsDNA, and embedding the dsDNA into Hemin and MnTMPyP to catalyze a Na2S2O3 and H2O2 mixed solution to generate H2S. H2S reacts with BiOBr modified on an electrode to generate a BiOBr / Bi2S3 compound, so that the photocurrent is greatly increased, the change of the photocurrent and the concentration of a target object are in a linear relationship in a certain range, HCR signal amplification is designed on the basis of specific recognition of malathion and an aptamer thereof, biocatalysis is utilized to induce a BiOBr / Bi2S3 semiconductor heterojunction to amplify a signal, therefore, high-sensitivity and high-selectivity photoelectric method detection of malathion is realized.

The invention discloses a preparation method and application of a bismuth oxybromide / biochar composite photocatalyst, and aims at solving the problems that an existing biochar adsorbent cannot be repeatedly used and is small in adsorption capacity to prepare the bismuth oxybromide / biochar composite photocatalyst. According to the preparation method, adopting hydrothermal method firstly to synthesis bismuth oxybromide, then preparing the bismuth oxybromide / biochar composite visible-light-induced photocatalyst with high specific surface area by adopting a ball milling method. According to the photocatalyst disclosed by the invention, biochar with good adsorption performance and BiOBr are subjected to ball-milling mixing, so that the adsorption capacity of Biochar to organic pollutants is improved, meanwhile, compared with Biochar, the capacity of the bismuth oxybromide / biochar compound for synergistically adsorbing and degrading the organic pollutants under visible light is further enhanced, and the photocatalytic material can be applied to visible light catalytic degradation of pollutants in the field of energy. And the biochar is provided with the capability of repeated use.

The invention provides a niobium-doped bismuth oxybromide catalyst and a preparation method and a use method thereof. The preparation method comprises the following steps: 1, heating an alcohol solvent until the alcohol solvent is boiled, and naturally cooling, 2, sequentially adding a bismuth salt compound, a niobium compound and a bromine compound, mixing and fully stirring, 3, adding a neutralsolution, 4, carrying out high-pressure constant-temperature reaction, and 5, cooling to room temperature, carrying out centrifugal separation, respectively washing with water and an ethanol solution,drying, and collecting the powder to obtain the flower-ball-shaped niobium-doped bismuth oxybromide. The photocatalyst prepared by the preparation method disclosed by the invention is Nb-BiOBr, the photocatalyst has good visible light photocatalytic degradation organic matter performance, higher photocatalytic activity and photo-induced electron hole separation efficiency, the degradation efficiency of the photocatalyst is 6.4 times that of BiOBr in the prior art, and the photocatalyst is environmentally friendly, harmless, low in price, controllable in method and easy to operate and has wideapplication prospects in the field of environmental pollution and governance.

The invention provides a preparation method and an application of a magnetic hydrotalcite / bismuth oxybromide compound, and belongs to the field of inorganic photocatalysis. The compound comprises magnetic hydrotalcite and bismuth oxybromide. The preparation method comprises the following steps: synthesizing hydrotalcite by a coprecipitation technology, synthesizing magnetic hydrotalcite by a solvothermal technology, and finally synthesizing the magnetic hydrotalcite / bismuth oxybromide compound by the solvothermal technology and a calcining technology. The magnetic hydrotalcite / bismuth oxybromide compound of the invention overcomes the defects of bismuth oxybromide and magnetic zinc-aluminum hydrotalcite, has a high electron-hole separation efficiency and high transfer speed, reduces the recombination of electron hole pairs, improves the catalytic reduction activity of visible light to Cr(VI), has the advantages of low cost, convenience in preparation and easiness in separation, can bewidely used in photocatalytic reduction of heavy metal chromium in wastewater to achieve a catalytic effect of 98%, also has a magnetic separation effect, a good stability and a good recyclability, and also has a good catalytic reduction activity in actual wastewater treatment.

The invention discloses a preparation method of a chitosan hybrid bismuth oxybromide micro-nano multi-layer material. The preparation method comprises the steps of: slowly adding a chitosan dispersioninto a bismuth salt solution, conducting magnetic stirring for even dispersing; slowly adding a bromine salt solution into the system under stirring, conducting stirring for even dispersing, then transferring the reaction system into a reaction kettle, conducting hydrothermal reaction at 120-300 DEG C for 6-20 h, and separating a product by suction filtration, conducting washing with distilled water, and conducting drying in vacuum to obtain the chitosan bismuth oxybromide micro-nano multilayer material. According to the invention, chitosan is adopted as a template guiding agent and a structure inducing agent, and a bismuth salt is combined with a bromine salt to form bismuth oxybromide by polymer hydrothermal assist, and the bismuth oxybromide photocatalytic material is promoted by an amino group in a chitosan molecular segment to have highly exposed crystal plane and rich oxygen vacancies, thus further the absorption of the catalyst in a visible region is expanded, and the chitosanhybrid bismuth oxybromide micro-nano multi-level photocatalytic material has high photocatalytic activity under simulated sunlight.

The invention relates to a preparation method of a bismuth molybdate-bismuth oxybromide composite visible photocatalyst, and relates to the technical field of inorganic photocatalysis materials. The method is mainly characterized in that bismuth molybdate-bismuth oxybromide precursors are obtained through a one-step technology to form a uniform p-n heterojunction between bismuth molybdate-bismuth oxybromide, so the compounding of electrons and holes is effectively inhibited, thereby the photocatalysis performance is improved. The rhodamine B degradation rate of the bismuth molybdate-bismuth oxybromide composite visible photocatalyst reaches 93.3% in 30 min, the rhodamine B degradation rate of single bismuth molybdate is 70.6% in 30 min, the rhodamine B degradation rate of single bismuth oxybromide is 9.05% in 30 min, the catalyst can be recovered in a simple settlement mode, the recovery rate is 90.9%, the rhodamine B degradation rate of the recovered catalyst reaches 81.9% in 30 min, and the catalyst has good application prospect in photocatalytic degradation of organic pollutants in heterocyclic aromatic dye wastewater.

The invention relates to the technical field of photocatalysis, and particularly discloses a photocatalytic material and a preparation method and application thereof, and the main components of the photocatalytic material are KPF6 and BiOBr. The photocatalytic material provided by the embodiment of the invention has excellent performance of preparing H2O2 by photocatalysis, is a BiOBr composite material improved by KPF6, can be used for efficiently preparing H2O2 by photolysis of water, is prepared by dropwise adding a potassium hexafluorophosphate solution into a bismuth oxybromide precursor solution by adopting a one-step hydrothermal method for hydrothermal reaction, is simple to operate. The problem that an existing BiOBr photocatalyst is not high in hydrogen peroxide synthesis efficiency in the process of preparing hydrogen peroxide through water photolysis is solved. Moreover, the preparation method provided by the invention is simple, and the prepared photocatalytic material is stable in performance and low in cost and has a good market application prospect.

The invention discloses a bismuth oxybromide-copper oxide nano composite photo catalyst and a preparation method thereof and relates to the technical field of preparation of photo catalyst materials.Firstly, cetyl trimethyl ammonium bromide reacts with bismuth nitrate to prepare bismuth oxide nano sheets, and then copper oxide nano crystal is generated on the bismuth oxide nano sheets after reaction. The microstructure of the prepared bismuth oxybromide-copper oxide nano composite photo catalyst is that the copper oxide nano crystal evenly grows on the surfaces of the circular bismuth oxide nano sheets, the diameter of the bismuth oxide nano sheets is 0.5-2 micrometers, the thickness of the bismuth oxide nano sheets is 20-50 nm, the copper oxide nano crystal is quantum dot, and the particle size is within 1-5 nm. The bismuth oxybromide-copper oxide nano composite photo catalyst has high visible-light catalytic activity, can remarkably improve the degrading rate of organic dye and is expected to be used for helping sunlight to degrade organic pollutants in water. The preparation method is simple in technology and device, easy to operate and good in repeatability, raw materials arelow in cost and easy to obtain, and the bismuth oxybromide-copper oxide nano composite photo catalyst is suitable for industrialization production.

The invention discloses bismuth vanadate / bismuth oxide and a preparation method. The preparation method comprises the following steps: firstly adding bismuth nitrate in nitric acid, adding ammonium metavanadate in a sodium hydroxide solution, mixing the two solutions, regulating and controlling the pH value and obtaining bismuth vanadate through drying, grinding and calcining. The bismuth vanadate / bismuth oxide and the preparation method disclosed by the invention have the benefits that after in-situ conversion of bismuth oxybromide by using sodium hydroxide, bismuth oxide in the bismuth vanadate / bismuth oxide is obtained; bismuth vanadate / bismuth oxide powder is obtained through mixing and dispersing the obtained bismuth vanadate powder and the bismuth oxide powder, then adding a sodium hydroxide solution, stirring, washing and drying; the bismuth vanadate / bismuth oxide has the advantages of being easy to regulate and control in ratio between two-phase components, low in production cost, simple and convenient in process and the like.