47 results about "Bismuth oxybromide" patented technology

Disclosed in the present invention are an oxygen-enriched carbon quantum dot composite bismuth oxybromide nanosheet material, and a preparation method therefor and the use thereof. The preparation method comprises: sequentially uniformly dissolving Bi(NO3)3·5H2O and oxygen-enriched carbon quantum dots in a mannitol solution, then adding KBr thereto, stirring the mixture, then subjecting same to a solvothermal reaction, and then subjecting same to washing, suction filtration and drying, so as to obtain an oxygen-enriched carbon quantum dot composite bismuth oxybromide nanosheet material. The preparation method of the present invention is simple, and the bismuth oxybromide nanosheet is more easily and uniformly modified with the oxygen-enriched carbon quantum dots. The oxygen-enriched carbon quantum dots provide more active sites for bismuth oxybromide, thereby overcoming the defects of monomer bismuth oxybromide having a limited visible-light response and few active sites, optimizing the electron transmission performance of monomers, enhancing the light absorption intensity of the material, effectively guiding the charge flow, accelerating the separation and transfer of photo-generated charges, and achieving efficient visible light catalytic activity.

The invention relates to a high-purity HDPE composite material with a self-cleaning function for an ultra-clean barrel, and belongs to the technical field of high polymer materials. Comprising the following raw materials in parts by weight: 85-95 parts of high-density polyethylene, 3-5 parts of a modified filler, 1-2 parts of an antioxidant and 0.5-1.5 parts of a plasticizer. Nano silicon dioxide is deposited on the surface of bismuth oxybromide by a modified filler through a sol-gel method, so that the photocatalytic efficiency and the material stability are improved, and the dispersity in an HDPE (High-Density Polyethylene) matrix is improved; and then a silane coupling agent KH570 is grafted on the surface of silicon dioxide, so that the material is endowed with hydrophobic performance, pollutant adhesion is prevented, meanwhile, the compatibility with HDPE is enhanced, and the mechanical property of the composite material is improved. Acetyl tributyl citrate and epoxidized soybean oil are mixed according to the ratio of 1: 1 to serve as an environment-friendly plasticizer, and the processability, flexibility and impact strength of HDPE are synergistically improved. The HDPE composite material prepared by the invention has a self-cleaning function, excellent mechanical properties and environmental friendliness, and is suitable for ultra-clean barrel products.

The invention relates to the technical field of photocatalysts, in particular to a bismuth-defect bismuth oxybromide-sulfur-defect bismuth sulfide bromide heterojunction and a preparation method and application thereof in photocatalytic CO2 reduction, Bi (NO3) 3.5 H2O, thiourea, cetyltrimethylammonium bromide (CTAB) and the like are used as raw materials, and the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction is prepared through a two-step hydrothermal method. According to the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction, bismuth vacancies and sulfur vacancies are introduced, the visible light absorption range of the material is expanded through a proper amount of double vacancies, more electron capture centers are provided, and the separation efficiency of photo-induced electrons and the vacancies is improved, so that the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction has excellent performance of photocatalytic reduction of CO2, and the preparation method of the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction is suitable for large-scale production and application of the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction. CO2 can be reduced into a single product CO, and the photoreduction efficiency of the carbon dioxide can be improved.

According to the graphene quantum dot regulated bismuth oxybromide photocatalytic material as well as the preparation method and the application thereof provided by the invention, the two-dimensional photocatalytic material Bi24O31Br10 is combined with the GQDs with good conductivity to form a composite structure, so that the photocatalytic efficiency is remarkably improved. According to the structure, the specific surface area of the material is increased, more active sites are provided, and separation and transmission of photogenerated charges are promoted, so that the rate and efficiency of a photocatalytic reaction are improved. Due to the introduction of the GQDs, the GQDs / Bi24O31Br10 composite material can effectively utilize a visible light part in a solar spectrum, so that the light response range of a photocatalyst is expanded, and the photocatalyst can absorb light energy in a wider spectral range. The GQDs / Bi24O31Br10 composite material prepared by the invention is suitable for photocatalytic degradation of antibiotics such as norfloxacin and the like, and has a wide application prospect.

The invention relates to a preparation method and application of an ultra-efficient nitrate-based free radical activation catalyst, and the preparation method comprises the following steps: S1, dissolving bismuth nitrate Bi (NO3) 3.5 H2O and polyvinylpyrrolidone (PVP) in a mannitol solution; s2, adding potassium bromide into the solution in the step S1, and performing ultrasonic treatment to form a white suspension; s3, transferring the suspension into a high-pressure reaction kettle for hydrothermal reaction; and S4, after the reaction is completed, cooling, centrifugally collecting precipitates, washing, and carrying out vacuum freeze drying to obtain the bismuth oxybromide BixOBr nanosheet catalyst. According to the application of the super-efficient nitrate-based free radical activation catalyst in degradation of organic pollutants, the bismuth oxybromide BixOBr nanosheet catalyst is added into a water body containing nitrate, the nitrate is activated to generate free radicals by utilizing the piezoelectric effect induced by photoinduced deformation of the photocatalyst under the condition that an external electric field and an oxidizing agent are not needed, and the degradation efficiency of the nitrate-based free radical activation catalyst is improved. Therefore, organic pollutants are degraded.

The present invention belongs to the technical field of photocatalytic CO₂ reduction, and specifically relates to a dual-MOFs-derived zinc oxide / bismuth oxybromide composite photocatalyst, its preparation method and application. In the present invention, ZIF-8 and Bi-MOF are first prepared by a solvothermal method. After halogenating Bi-MOF with ammonium bromide, ZIF-8 is in-situ grown, and a composite photocatalyst with a dual-MOFs structure composed of zinc oxide particles with a dodecahedral structure derived from ZIF-8 and bismuth oxybromide derived from Bi-MOF is prepared by a one-step calcination method. Under room temperature, xenon lamp illumination, and without a sacrificial agent, this catalyst can effectively catalyze the reduction of carbon dioxide into carbon monoxide and methane, and has good photocatalytic CO₂ reduction performance, stability and repeatability. This preparation method has low cost, high reproducibility, and mild and controllable preparation conditions, and has broad application prospects in the field of photocatalytic CO₂ reduction.

The invention discloses a preparation method and application of a BiOBr-based composite material, and the preparation method of the BiOBr-based composite material comprises the following steps: (1) adding a bromine-containing precursor solution into a bismuth-containing precursor solution to obtain a mixed solution, and dropwise adding ethanolamine into the mixed solution; and (2) adding TPP into the solution after the reaction in the step (1), carrying out ultrasonic dispersion, transferring into a hydrothermal reaction kettle after dispersion, carrying out hydrothermal reaction, and carrying out centrifugal separation after the reaction to obtain the BiOBr-based composite material. The TPP / BOBZ type heterojunction material prepared by the invention is a nanosheet, the synthesis steps are simple, the obtained material integrates the characteristics of a bismuth oxybromide-based material and a TPP material, and TPP / BOB shows excellent sterilization activity.

The invention discloses a full-spectrum response BiOBr / Bi2O3-x / WO3-x double-S heterojunction material rich in oxygen vacancy as well as a preparation method and application of the full-spectrum response BiOBr / Bi2O3-x / WO3-x double-S heterojunction material. The heterojunction is prepared by taking bismuth nitrate pentahydrate, potassium bromide and WO3-x microspheres containing oxygen vacancies as main raw materials through a wet impregnation method, and the value range of x in Bi2O3-x and WO3-x is 0 < = xlt; 1 represents that the two have oxygen vacancies with certain concentration. Due to the introduction of the wide-spectrum response semiconductor materials WO3-x and Bi2O3-x, the double-S-type heterojunction shows a remarkable full-spectrum absorption capability. Meanwhile, oxygen vacancies in the material can serve as effective electron capture centers and transmission channels, and separation of photo-induced electron-hole pairs is effectively promoted. Based on the synergistic coupling effect among BiOBr, Bi2O3-x and WO3-x, the heterojunction can degrade ciprofloxacin (CIP) and reduce Cr (VI) (85% and 74% respectively) at the same time. The heterojunction material provided by the invention is simple in preparation process and good in repeatability, and has important application potential in the field of environmental governance.

The invention discloses a light and wave multi-energy complementary power generation device based on a bismuth oxybromide thin film material and an oscillating water column. The light and wave multi-energy complementary power generation device comprises an inflow pipeline, an oscillating water column power generation unit and a photovoltaic power generation unit. The inflow pipeline and the oscillating water column pipeline form an L-shaped fluid channel, periodic compression and expansion of air in the pipeline are triggered by guiding wave kinetic energy, the bismuth oxybromide film is driven to vibrate, and wave energy is converted into electric energy through the piezoelectric effect of the bismuth oxybromide film. Membrane pores excite a synergistic oscillation rate by directing airflow through the membrane. The photovoltaic power generation unit is integrated on the top of the pipeline, incident light energy is directly converted into electric energy, and complementation with wave energy power generation is formed. Efficient collaborative conversion of light energy and wave energy is achieved, the L-shaped pipeline structure optimizes an airflow path to enhance the compression effect, the corrosion resistance of the film guarantees long-term stability in the marine environment, the structure is concise, the cost is reduced, and the system robustness is improved; the technical problems that a traditional ocean energy system is low in efficiency, single in dependence and poor in environmental adaptability are solved.

The invention belongs to the technical field of air pollution prevention and control of photocatalytic materials, and particularly relates to a nitrogen-doped bismuth oxybromide-graphite phase carbon nitride heterojunction photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: 1) respectively dissolving ammonium sulfate, bismuth nitrate and potassium bromide in water, mixing and transferring into polytetrafluoroethylene, and obtaining nitrogen-doped bismuth oxybromide by utilizing a hydrothermal method; 2) adopting a hydrothermal-assisted thermal polymerization method, obtaining a precursor through a melamine hydrothermal reaction, and performing nitrogen calcination to obtain tubular graphite-phase carbon nitride; 3) adding the mixed sample into methanol, and adopting a mechanical stirring method to obtain the nitrogen-doped bismuth oxybromide-graphite phase carbon nitride heterojunction photocatalyst. Due to the formation of the heterojunction, the activity of the nitrogen-doped bismuth oxybromide-graphite phase carbon nitride in photocatalytic reduction of carbon dioxide can be greatly improved.

The application provides a nitrogen-doped carbon-encapsulated sheet layer stacked microrod-shaped bismuth material and a preparation method and application thereof. The microrod-shaped bismuth matrix is tightly stacked by a plurality of sandwiched nanosheet units, the inside of the sheet layer is metal bismuth, and the outside is a nitrogen-doped carbon shell. The nitrogen-doped carbon-encapsulated sheet layer stacked microrod-shaped bismuth material is obtained by sintering and carbonization of the sheet layer stacked structure containing the microrod-shaped bismuth oxybromide coated with dopamine. The nanosheet units of the material are stacked to form a microstructure, and the nitrogen-doped carbon is tightly encapsulated outside, so that when the material is used as a negative electrode of a sodium ion battery, the transmission path of sodium ions can be effectively shortened to realize fast charging and discharging, direct contact between electrolyte and metal bismuth can be prevented, and the volume expansion of the material during the sodium intercalation / deintercalation process can be fully relieved, thereby greatly improving the rate performance and cycle stability of the battery.

This invention relates to the field of nanoscale full-spectrum photocatalytic materials, and particularly to a method for preparing a molybdenum selenide / oxygen-deficient bismuth oxybromine@gold three-phase Z-type heterojunction photocatalyst. This method solves the problems of low photogenerated electron-hole separation efficiency, narrow full-spectrum response range, and poor stability in existing bismuth-based photocatalysts. The preparation method involves first preparing oxygen-deficient BiOBr nanospheres via a solvothermal method, then directly reacting tetrachloroauric acid with oleylamine in toluene to prepare small-particle-size monodisperse Au nanoparticles, which are then combined with oxygen-deficient BiOBr to prepare a BiOBr@Au nanosphere core-shell structure. Finally, a MoSe2 / oxygen-deficient BiOBr@Au three-phase composite material is prepared via a hydrothermal reaction. The catalyst of this invention exhibits absorption capacity under the full spectrum of light, and simultaneously achieves a synergistic enhancement of carrier separation efficiency and strong redox capability, demonstrating excellent photocatalytic activity and the ability to efficiently degrade pollutants and produce hydrogen.

The invention discloses a modified bismuth oxybromide composite photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of photocatalytic organic synthesis. The preparation method comprises the following steps: mixing Bi (NO3) 3, KBr and Cu (NO3) 2, adding chlorophyll, and stirring to obtain the modified bismuth oxybromide composite photocatalyst. The Cu-doped chlorophyll co-regulated nano bismuth oxybromide photocatalyst is synthesized, the Cu-doped chlorophyll co-regulated nano bismuth oxybromide photocatalyst is used for photocatalysis of bimolecular oxidative coupling of benzylamine and methylamphetamine, bimolecular coupling of methylamphetamine and benzylamine is carried out under 10W visible light for the first time, the conversion rate can reach 99.5%, the product is alpha-methyl-N-(benzylidene) phenylethylamine, and the product has a wide application prospect. The method realizes detoxification treatment of methylamphetamine, realizes efficient and green synthesis of an imine compound under a noble metal-free condition, and can efficiently photocatalyze oxidative coupling of methylamphetamine and chemically degrade pollutants in water.

The invention discloses a portable detection device and a detection method for detecting microcystic toxins based on bismuth oxybromide doped biomass carbon, and belongs to the field of photoelectrochemical detection devices. The prepared BiOBr-coated BC nano composite material is used as a working electrode and is applied to a detection device, and the detection device further comprises a control system and a detection system. The detection system is fixed in the detection system shell, and the control system is fixed in the control system shell. Wherein the control system controls the LED lamp to emit exciting light to irradiate the working electrode, and the nano material in the detection system enters an excited state after receiving light to generate current. After a detection target object is added, separation of hole electron pairs can be influenced, so that the change of current is influenced. The concentration of the detected object is reflected by detecting the current change after the target objects with different concentrations are added. The device provided by the invention can realize detection of weak current signals, and meanwhile, compact and small equipment provides a scheme for portable detection.

The method comprises the following steps: firstly, preparing ferric vanadate through a hydrothermal reaction and calcination, then reacting the ferric vanadate with bismuth nitrate and potassium bromide to synthesize ferric vanadate bismuth oxybromide composite particles, finally adding the composite particles into a solvent, mixing the composite particles with polyvinylidene fluoride and the like to prepare a membrane casting solution, and finally, preparing the membrane casting solution into the photocatalytic membrane. And standing, degassing, forming a film and curing to obtain the photocatalytic film. According to the method, the photocatalytic efficiency and the visible light utilization capability are improved by utilizing the bismuth oxybromide iron vanadate heterojunction, the bismuth oxybromide iron vanadate heterojunction is compounded into the polyvinylidene fluoride matrix, the problems of catalyst recovery and falling are solved, and the membrane is endowed with anti-pollution and self-cleaning capabilities. And the preparation process ensures sufficient construction of heterojunctions, good interfacial compatibility and complete membrane structure, so that interfacial charges are smoothly transferred, the structural defects are reduced, efficient synergy of photocatalysis and membrane separation technologies is realized, the antibiotic wastewater treatment effect is improved, and the method has a good application prospect.

The application discloses a preparation method of a bismuth sulfide nanorod / bismuth oxybromide composite photocatalytic material. The method adopts a hydrothermal method, first prepares a bismuth sulfide precursor, and then grows the bismuth sulfide nanorod / bismuth oxybromide composite material through hydrothermal growth after the bismuth sulfide precursor is uniformly stirred with bismuth nitrate pentahydrate and sodium bromide. The composite material has a unique nano structure and good photocatalytic performance by adjusting the mass of the bismuth sulfide precursor in the composite material. When 2 mmol of bismuth oxybromide and 0.05 g of the bismuth sulfide precursor are used to hydrothermally synthesize the bismuth sulfide nanorod / bismuth oxybromide composite material, the composite material has the optimal rhodamine B removal performance, and the removal rate can reach 99.2% after 30 min of dark adsorption and 15 min of photocatalytic reaction; meanwhile, the bismuth sulfide nanorod / bismuth oxybromide composite photocatalytic material also has good removal effects on tetracycline, methyl orange and other organic pollutants.

The invention discloses a preparation method of a gold-loaded bismuth-based nano material, which comprises the following steps: adding potassium bromide and bismuth nitrate pentahydrate into a mixed solution of deionized water and ethanol, heating and stirring; after the reaction is finished, filtering, collecting precipitates and drying to form bismuth oxybromide; the preparation method comprises the following steps: uniformly mixing tantalum pentoxide, bismuth oxybromide, bismuth oxide, sodium chloride and potassium chloride, putting the mixture into a crucible, putting the crucible into a muffle furnace, calcining, cleaning with deionized water, and finally drying to obtain the Bi4TaO8Br catalyst. The preparation method comprises the following steps: adding a Bi4TaO8Br catalyst into deionized water, stirring and dispersing uniformly, then adding a chloroauric acid solution and a methanol solution, illuminating by a xenon lamp, and stirring; after the reaction is finished, filtering, collecting a precipitate, and drying to form Au-Bi4TaO8Br. According to the bismuth-based piezoelectric catalyst Bi4TaO8Br prepared by the preparation method disclosed by the invention, metal gold is loaded on the surface of the bismuth-based piezoelectric catalyst Bi4TaO8Br, so that the good water oxidation performance of the catalyst is ensured, meanwhile, the loaded metal gold can provide sites required by an oxygen reduction reaction, and the purpose of efficiently preparing H2O2 by coupling water oxidation and the oxygen reduction reaction is achieved.

The invention provides a preparation method of a polyion liquid modified bismuth oxygen bromide photocatalyst, which comprises the following steps: dissolving 1-vinyl-3-butylimidazolium bromide in acetone, and adding Bi (NO3) 3.5 H2O to obtain a precursor solution; and dropwise adding a cross-linking agent, adding an initiator azodiisobutyronitrile, reacting, washing, and drying to obtain the product. The invention further provides application, and the photocatalyst is used for photocatalytic CO2 reduction reaction and used for degrading tetracycline in a water body. The light absorption capacity of the material is enhanced through an in-situ cross-linking polymerization strategy, the charge separation efficiency and stability are improved, and the catalyst can be applied to photocatalytic CO2 reduction and organic pollutant degradation.

The invention provides a bismuth oxybromide modified strontium titanate photocatalytic material and a preparation method thereof. According to the method, the synergistic effect of bromide and bismuth salt is adopted, through complexing of hydroxyl (-OH) and Bi < 3 + > ions, the nucleation rate of BiOBr is successfully controlled, particle aggregation is inhibited, and finally the photocatalytic composite material with the flower-like microsphere structure is formed. By constructing the SrTiO3 / BiOBr heterojunction, the forbidden band width of the composite material is obviously reduced, the visible light absorption range is obviously widened, the separation efficiency of photon-generated carriers is improved, and the photocatalytic performance is promoted to be enhanced. The composite material shows remarkable photocatalytic activity under visible light, formaldehyde in air can be efficiently removed, and the removal rate is 70% or above. The preparation process is simple and environment-friendly, and has a wide application prospect, especially in the fields of air purification and water treatment.

The invention discloses a circulation-type photoelectric synergistic catalytic filtration system for removing new pollutant wastewater by efficiently activating molecular oxygen, which has multiple advantages of efficiently activating molecular oxygen, realizing photoelectric synergistic interaction and enhancing mass transfer by a flow system, and is beneficial to realizing efficient removal of new pollutants. The circulation type photoelectric synergistic catalysis filtering system comprises a shell, a negative electrode, a positive electrode and an interlayer, wherein an anode, a non-woven fabric interlayer, a cathode and a sealing ring are sequentially arranged in the shell; wherein the anode is a bismuth oxybromide / carbon nitride / samarium-bismuth vanadate photoelectrode, and the cathode is a ferrocobalt diatom confinement carbon nanotube electrode; the broadband spectral response material and the novel catalyst design significantly improve the anti-interference performance, and adapt to complex water quality and low-concentration pollution scenes. New pollutant wastewater can be efficiently removed after being illuminated and electrified in the circulation type photoelectric concerted catalytic filtration system in a circulation flow mode, and the removal rate of ibuprofen within 2 hours can reach 96%. The method is simple in design, easy to operate, low in cost and small in energy consumption, solves the problems of low removal efficiency, high energy consumption and the like of a common treatment system, further reduces the operation cost in cooperation with solar full spectrum utilization and low catalyst dosage design, and shows the comprehensive advantages of high efficiency, stability, economy and environmental protection.

The invention discloses a coated bismuth ferrite and bismuth oxybromide flaky water treatment catalyst and a preparation method and application thereof, and belongs to the technical field of sewage treatment.The coated bismuth ferrite and bismuth oxybromide flaky water treatment catalyst structurally comprises a two-dimensional mullite phase Bi2Fe4O9 nanosheet and a continuous film coated on the surface of the two-dimensional mullite phase Bi2Fe4O9 nanosheet, and the continuous film is composed of bismuth oxybromide nanoparticles; the side length of the two-dimensional mullite phase Bi2Fe4O9 nanosheet is 500 to 600 nm, the thickness of the two-dimensional mullite phase Bi2Fe4O9 nanosheet is 100 to 200 nm, and the particle size of the bismuth oxybromide nanoparticles is 5 to 10 nm; under visible light, the coated bismuth ferrite and bismuth oxybromide flaky water treatment catalyst removes azo dyes in wastewater by activating persulfate. The coated bismuth ferrite and bismuth oxybromide flaky water treatment catalyst provided by the invention has a compact heterogeneous interface and a relatively large specific surface area, the number of active sites is large, meanwhile, the persulfate activation capability is strong, and the coated bismuth ferrite and bismuth oxybromide flaky water treatment catalyst has a wide application prospect in the aspect of azo-containing dye wastewater treatment.

The invention discloses a preparation method and application of a bismuth oxybromide supported gold monatomic photocatalytic material, and relates to the technical field of organic matter halogenation. In the photocatalytic material, the supported metal material is supported on the precursor in a monatomic form, and the metal material is uniformly dispersed in the monatomic form, so that the photocatalytic material shows excellent conversion rate and selectivity in a photocatalytic organic matter halogenation reaction. The invention also provides a preparation method and application of the photocatalytic material. According to the invention, gold single atoms are combined with a bismuth oxybromide photocatalytic material, so that the photocatalytic performance of the material is improved, the material shows excellent performance in photocatalytic toluene bromination, toluene can be rapidly halogenated, the reaction rate is relatively high, the selectivity is relatively high, the reaction conditions are mild, and environmental pollution and resource waste are not easy to cause.

The invention discloses a synthesis method and application of a bismuth-rich bismuth oxybromide solid solution single crystal nanosheet for visible light driven full water decomposition. According to the method, bismuth oxide and lanthanum oxide are used as raw materials, a binary molten salt system of potassium bromide and lithium bromide is used as a bromine source, the bismuth-rich bismuth oxybromide solid solution single crystal is synthesized in situ, in the process, the stoichiometric ratio of the bismuth oxide to the lanthanum oxide is regulated and controlled, complete mutual dissolution of the lanthanum and the bismuth in crystal lattices can be achieved, and the bismuth-rich bismuth oxybromide solid solution single crystal is obtained. Therefore, the formed bismuth-rich bismuth oxybromide solid solution is stable in structure. The prepared bismuth-rich bismuth oxybromide solid solution monocrystal nanosheet has the advantages of simple synthesis process, good repeatability and the like, meets the requirements of large-scale production, not only has an energy band structure required by a full-water decomposition reaction, but also can effectively inhibit the compounding process of photo-induced electron-hole pairs, and is suitable for large-scale production. The separation efficiency and the surface migration rate of current carriers are remarkably improved, so that wide application prospects are shown.

The invention discloses an application of a QL-COF-BiOBr composite material in synchronous reduction of Cr (VI) and degradation of butyl xanthate composite wastewater treatment. The composite material is composed of a QL-COF matrix and bismuth oxybromide nanoparticles loaded on the surface and in pores of the QL-COF matrix and is used for treating composite wastewater containing Cr (VI) and butyl xanthate, and Cr (VI) reduction (the reduction rate is larger than or equal to 90%) and butyl xanthate degradation (the degradation rate is larger than or equal to 95%) are synchronously achieved through the adsorption-photocatalysis synergistic effect. The composite material has high adsorption capacity and high photocatalytic activity, the preparation process is simple, the stability is high, large-scale production is easy, the process is simplified during composite wastewater treatment, the cost is low, and the composite material is suitable for industrial popularization and application.

The invention relates to the technical field of lithium batteries, in particular to a V2O5-coated BiOBr composite positive electrode material as well as preparation and application thereof. The composite positive electrode material is obtained by compounding bismuth oxybromide and vanadium pentoxide, and the composite catalyst has PN heterojunction. The V2O5-coated BiOBr heterojunction composite positive electrode material is created, a new direction is developed for the applicable positive electrode material of the lithium oxygen battery, meanwhile, the lithium oxygen battery prepared from the positive electrode material is relatively low in overpotential, and the energy efficiency of the battery is greatly improved. The invention also provides a synthesis method of the V2O5-coated BiOBr heterojunction composite positive electrode material, the V2O5-coated BiOBr heterojunction composite positive electrode material is synthesized by adopting a sol-gel method, and the method is simple, convenient and easy to operate, and is beneficial to popularization and application of a new material.

The invention provides a preparation method of a Bi4O5Br2-ZnO composite photocatalyst, which comprises the following steps: mixing an aqueous solution of sodium bromide and an ethanol solution of bismuth nitrate pentahydrate, adjusting the pH value of the mixed solution by using ammonia water, adding nano zinc oxide, putting the mixed solution into a high-pressure kettle, carrying out hydrothermal reaction for sufficient time under the conditions of constant temperature and constant pressure, and carrying out vacuum drying to obtain the Bi4O5Br2-ZnO composite photocatalyst. And cooling, precipitating, washing and drying the reactant to finally obtain the Bi4O5Br2-ZnO composite photocatalyst. The preparation method is simple, raw materials are easy to obtain, and the method is suitable for large-scale amplification. According to the Bi4O5Br2-ZnO composite photocatalyst prepared by the preparation method disclosed by the invention, an ultraviolet visible light absorption spectrum has red shift by reducing a band gap, so that the light wave absorption range is remarkably widened, and the utilization rate of the catalyst to sunlight is effectively improved; an interface formed by zinc oxide and bismuth-rich bismuth oxybromide can effectively promote migration and separation of photon-generated carriers, increase reaction active sites and improve the efficiency and stability of photocatalytic reduction of CO2 into CO so as to achieve the purpose of assisting carbon emission reduction.

The invention discloses a preparation method and application of a bismuth tungstate nanosheet composite material, and the preparation method comprises the following steps: preparing bismuth tungstate nanosheet powder and bismuth oxybromide nanoflower powder in advance, then mixing and stirring the bismuth tungstate nanosheet powder and the bismuth oxybromide nanoflower powder uniformly, and performing centrifugal drying to obtain a B delta B finished product; according to the preparation method of the bismuth tungstate nanosheet composite material, the bismuth tungstate nanosheet composite material is rich in bismuth vacancies; the bismuth tungstate nanosheet composite material is applied to photocatalytic degradation of antibiotic pollutants. The bismuth tungstate nanosheet loaded bismuth oxybromide nanoflower composite material rich in bismuth vacancy is prepared from bismuth tungstate nanosheet powder and bismuth oxybromide nanoflower powder, compared with a monomer, the light absorption and oxidation reduction capacity is optimized, photo-generated electron-hole pairs can be effectively separated, the recombination rate of Bi2WO6 and BiOBr photo-generated carriers is effectively reduced, and the photocatalytic performance of the Bi2WO6 / BiOBr composite material is improved. The preparation process is simple, large-scale mass production is achieved, and huge application possibility is shown.

The present invention discloses a bismuth oxybromide / carbon nitride-based photocatalytic paper in the field of photocatalytic materials, a preparation method thereof, and uses thereof. The bismuth oxybromide / carbon nitride-based photocatalytic paper is prepared by hydrothermal reaction and then hot-pressing and compounding on a constant-temperature heating table using bismuth nitrate pentahydrate, carbon nitride, plant fiber, and cationic starch as raw materials. The present invention selects bismuth oxybromide / carbon nitride with good visible-light photocatalytic performance as the catalyst and loads it on natural plant fibers, which can avoid the agglomeration of bismuth oxybromide / carbon nitride nanomaterials, thereby ensuring the physical adsorption and catalytic activity of the photocatalyst. The bismuth oxybromide / carbon nitride-based photocatalytic paper prepared by the method of the present invention has good visible-light photocatalytic and physical adsorption properties, and can effectively degrade organic pollutants and kill bacteria. It can be applied to the field of fruit and vegetable preservation, which can not only effectively inhibit the growth of microorganisms, but also the good air permeability can avoid the problem of rotting and deterioration caused by excessive humidity.

The present application relates to a kind of bismuth oxybromide / biochar composite for nitrogen fixation and preparation method and its application in photocatalytic nitrogen fixation.The composite is composed of layered porous biochar and rose-like bismuth oxybromide, bismuth oxybromide nanosheet is vertically or obliquely oriented growth in the two-dimensional surface and three-dimensional pore inside of biochar, form 0D-2D face-face contact heterostructure, rather than traditional point-face contact.The preparation method includes controllable preparation of corn straw biomass BC carrier and in-situ growth induced by chemical bond.And its application in photocatalytic nitrogen fixation.By introducing the physical support function of biochar, the problems of BiOBr nanosheet easy to agglomerate, few surface active sites, weak nitrogen adsorption and activation ability, poor cycle stability and short service life are solved.

The present invention provides a metal-organic framework / bismuth oxybromide composite photocatalyst and its preparation and application, which relates to the technical field of water pollution detection and environmental catalysis. The metal-organic framework is Ce-MOF. Through hydrothermal reaction, the present invention combines the metal-organic framework with bismuth tetraoxide bromide to form a heterojunction, which modifies the photocatalyst. The structure of the heterojunction endows it with excellent charge mobility and light absorption coefficient in the visible light range, improves the absorption ability of the metal-organic framework / bismuth oxybromide in the visible light range, enhances the separation efficiency of photo-generated electron-hole pairs, increases the distribution of active sites and specific surface area on the surface of the composite photocatalyst, effectively improves the adsorption and photocatalytic performance of the photocatalyst, and thus shows good degradation effect when degrading organic phosphorus pollutants in water.