688 results about "Bismuth vanadate" patented technology

The preparation process of visible light responding photocatalytic film layer features that the core or substrate to be coated is set inside water solution with water soluble inorganic or organic Bi compound and V compound, additive, complexing agent, NaOH, KOH and HNO3 while ultrasonically stirring, and after processing for 1-360 min, the core or substrate with obtained visible light responding photocatalytic bismuth vanadate film layer in the surface is taken out and washed with water or organic solvent. Thus obtained material with loaded bismuth vanadate photocatalyst has powerful sterilizing, deterging and deodorizing functions.

The invention discloses bismuth vanadate powder and a preparation method thereof. The method comprises the following steps: firstly, bismuth-bearing compounds and vanadium-bearing compounds are respectively dissolved in a nitric acid, mixed and then added with a hexadecyl trimethyl ammonium bromide solution, the mol ratio of bismuth to vanadium to the nitric acid to hexadecyl trimethyl ammonium bromide is 1 to 1 to 2.5 to 0.025, and the mixture is stirred for 1 to 2 hours by magnetic force so as to form a bismuth vanadate precursor; the bismuth vanadate precursor is placed in a reaction kettle, undergoes hydrothermal treatment for 70 to 75 hours at a temperature of between 80 and 200 DEG C, cooled, centrifugally separated, and then added with a saturated sodium chloride solution of anhydrous ethanol and deionized water; ion-exchange is performed after the bismuth vanadate precursor is completely immersed, and then centrifugal separation is performed; and finally the bismuth vanadate precursor is washed for 3 to 5 times by mixture of the deionized water and ethanol, then the bismuth vanadate powder with microspheric and/or micro-flaky particles is prepared. The method has simple operation and mild conditions; and bismuth vanadate powder particles prepared are uniform, have large specific surface area, have the characteristics of good visible light response and high photocatalytic activity, and are suitable for industrialized production.

The invention discloses the methods of preparation for a superfine bismuth vanadate yellow pigment, the characteristics of its bismuth nitrate, partial vanadate or vanadate are the main raw material. Through controlling of its appropriate pH and temperature to get the Ultra-fine particles,which composed of bismuth vanadate yellow pigments.well by adding surfactant or changing vanadium source, itcan further control particle morphology, which were prepared by a diameter of 50-150 nm spherical particles, 100-200 nanometer length, width 50-100 nanometers Flake Vanadate Bismuth or length of 200-300 nm rod bismuth vanadate. The preparation of this invention is a simple process, and can be controlled morphology, the bismuth vanadate can meet the needs of different occasions, which can be widely used in the automotive topcoat, ink, paint and other requirements for a higher size area.

Bismuth vanadate pigments comprising at least one coating containing calcium fluoride, bismuth oxyfluoride or a lanthanide fluoride or oxyfluoride or a mixture thereof are useful for coloring paints, printing inks and plastics.

This invention relates to production process of pucherite yellow ceramic pigment, which takes sodium silicate as raw material to coat silicon dioxide. It takes sodium silicate as silicon source, coat silicon dioxide on surface of pucherite. For the strong inertia of silicon dioxide, it be able to withstand 1000 deg high temperature, and keep bright-colored after annealing of 1000 deg. This invention can eliminate harm to human body and pollution to environment in the process of production, solve the problem of heavy metal content are overproof in the export ceramic product of our country.

The invention discloses a ferro-nickel oxyhydroxide-modified bismuth vanadate photoelectrode and a preparation method and application thereof. The preparation method comprises the following steps: firstly, depositing bismuth oxyiodide on the surface of conductive glass, then coating the surface with the deposited bismuth oxyiodide with a dimethyl sulfoxide solution of vanadyl acetylacetonate, annealing, performing alkali soaking and rinsing with water to remove excessive vanadium pentoxide, and then drying to obtain a bismuth vanadate photoelectrode, and modifying ferro-nickel oxyhydroxide on the surface of the bismuth vanadate photoelectrode by adopting a cyclic voltammetry method in a three-electrode system, thus obtaining the ferro-nickel oxyhydroxide-modified bismuth vanadate photoelectrode. The invention further discloses applications of the ferro-nickel oxyhydroxide-modified bismuth vanadate photoelectrode in photoelectrocatalytic decomposition water. The prepared photoelectrode is used for producing hydrogen from photoelectrocatalytic decomposition water, can inhibit the compounding of photon-generated carriers, the service life of carriers generated by a BiVO4 photoelectrode can be effectively prolonged, and the oxygen evolution reaction on the surface of the photoelectrode can be promoted, so that the solar optic hydrogen conversion efficiency of a semiconductor photoelectrode can be improved.

The invention relates to a preparation method for a bismuth vanadate composite photocatalyst loaded with strontium ferrite, and belongs to the field of inorganic catalytic materials. According to the preparation method, bismuth vanadate adopts the structure of scheelite in the monoclinic system; while the degradation rate, of the composite photocatalyst loaded with the strontium ferrite, for methylene blue can reach 93 percent in 5h, the degradation rate, of a similar composite photocatalyst of bismuth vanadate loaded with ferroferric oxide, for the methylene blue can reach 80 percent in 8 h. Moreover, the prepared composite photocatalyst has photocatalysis activity in relatively-wide wavelength range, and can efficiently and cyclically degrade organic pollutants in heteroaromatic dye-type wastewater under the irradiation of ultraviolet light, visible light and natural light through photocatalysis. Meanwhile, the composite catalyst is convenient to recover with the recovery rate not less than 92 percent; the degradation rate, of the recovered composite catalyst, for the methylene blue can reach 60 percent in 5h. The preparation method is simple and has an excellent application prospect.

The invention discloses an organic solvent-water heating method for preparing football-shaped mesoporous BiVO4, comprising the following experimental steps: under the condition of stirring, bismuth nitrate and ammonium metavanadate are dissolved in a mixed solution of ethanol, ethylene glycol, nitric acid and laurylamine (oleylamine or mixed liquid of oleylamine and oleic acid); a sodium hydroxide (2mol / L) alcohol solution of ethanol and ethylene glycol with the volume ratio of 1 to 1 is used to regulate the pH of the solution to be equal to 1.5-3; the mixed solution is transferred in a stainless steel self-pressing vessel (the volume filling degree is about 70%) with a Teflon inner liner and is put in an incubator to carry out organic solvent - water heating treatment for 12h in constant temperature of 100 DEG C; and the mixed solution is naturally cooled to room temperature after taking out. The obtained product after the organic solvent - water heating treatment is filtered, is washed with deionized water and absolute ethanol and is dried for 12h at the temperature of 60 DEG C, and then football-shaped mesoporous BiVO4 micron particles with a monoclinic scheelite structure is obtained. The porous bismuth vanadate obtained by the method has good application prospects in the fields of photocatalysis, electrode materials, pigments, ion conductive ceramic, and the like.

The invention relates to a vanadate nanofiber photocatalyst and a preparation method thereof. The nanofiber photocatalyst is pucherite, or silver vanadate, or a compound of pucherite and silver vanadate. Organic vanadic salt, organic bismuth salt and the like with good alcohol solubility are taken as precursor reactors, a spinning solution is prepared by a PVP (Polyvinyl Pyrrolidone) and alcohol system, electrospining is performed by an electrospining device, then high-temperature roasting is performed, and the vanadate nanofiber photocatalyst is obtained. A prepared vanadate nanofiber is in a monoclinic crystal phase, is 30-100nm in diameter, has a narrower band gap, shows good visible light catalytic degradation ability for ofloxacin, a contaminant in water, and can be separated from a solution quickly by precipitation.

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

The invention relates to a visible light photocatalysed material for air purification and a method for air purification, which belong to the technical field of air purification through photocatalysis. The method is characterized by comprising the following steps: firstly, preparing nanometer photocatalyst powders of copper oxide/bismuth vanadate; secondly, dispersing and loading the photocatalyst powders on a metal mesh and a nylon base material by using silicon or titanium sol; and thirdly, naturally drying the photocatalyst powders or baking the photocatalyst powders at a temperature of between room temperature and 100 DEG C, so as to form a material with excellent visible light catalytic activity to toluene, formaldehyde and other air pollutants. At the same time, the surface of chitosan is modified by the nylon base material to effectively enhance the formaldehyde pollutant adsorption effect of the surface of the material. The visible light photocatalysed material for air purification and the method for the air purification have the advantages that the prepared nanometer photocatalysed material of the copper oxide/bismuth vanadate oxidizes the air pollutants through photocatalysis in daylight or under the normal lighting condition; and the catalyst loading base material does not need the temperature treatment at a temperature of more than 100 DEG C, can endow more indoor decorating materials with novel function of visible light catalytic purification, and has wide application prospect in the field of air pollution purification.

The invention discloses a method for preparing a pucherite-graphene composite photocatalyst. The method comprises the following steps: 1, preparing uniform porous olive-shaped pucherite powder from bismuth nitrate and ammonium metavanadate serving as raw materials by using an organic solvent-hydrothermal method; 2, preparing a graphene oxide colloid suspension; 3, pretreating the pucherite powder by adopting a silane coupling agent; and 4, simultaneously reducing the graphene oxide and compounding pucherite and grapheme by utilizing ultraviolet irradiation. In order to solve the problems that a conventional photocatalyst is low in visible light utilization rate and a single pucherite catalyst photon-generated carrier is easy to have compounding limitation on photocatalysis efficiency, the invention provides a high visible light activity photocatalyst preparation method which is low in production cost, simple and feasible. The pucherite-graphene composite photocatalyst prepared by adopting the method has good properties in the aspect of organic pollutant photocatalysis degradation, and has wide application prospects in the field of environment friendliness.

The invention relates the method for preparation of pucherite composite photocatalyst loaded on cobalt oxide. The photocatalyst comprises semi-conductor pucherite particle and cobalt oxide particle. The pucherite is monoclinic crystal system scheelite structure, and the diameter is 100nm-5mum. The grain diameter of cobalt oxide is 10nm-1mum. The mass ratio of cobalt oxide and pucherite is 1-100mg/g. The specific surface area of composite photocatalyst is 0.5-5m2/g. The said photocatalyst can effectively degrade the noxious and harmful chemical under the ultraviolet light, visible light and natural light radiating. And the photocatalyst is easy to separate and recover.

The invention provides a bismuth vanadate-graphene composite photocatalyst, and preparation and application thereof, and aims to provide a visible-light-responsive bismuth vanadate-graphene composite photocatalyst which has low production cost, short preparation period and high photocatalytic activity. The preparation method comprises the following production steps: 1, preparing a graphene oxide colloidal suspension; 2, preparing a bismuth vanadate-graphene oxide compound from bismuth nitrate, ammonium metavanadate and the graphene oxide colloidal suspension; 3, putting the product obtained in the step 2 in a microwave reactor to prepare a bismuth vanadate-graphene compound; and 4, performing centrifugal separation on the product obtained in the step 3, washing with redistilled water, and drying. The bismuth vanadate-graphene composite photocatalyst provided by the invention is high in photocatalytic activity and low in production cost; and the preparation method of the bismuth vanadate-graphene composite photocatalyst, provided by the invention, is simple to operate, short in preparation period, friendly to environment and suitable for commercial popularization.

The invention discloses a synthetic method for high-activity N-F co-doped bismuth vanadate visible light photocatalytic material prepared through the citric acid complexation sol-gel method and a preparation process. The method employs Bi(NO3)3.5H2O(97%) and NH4VO3(98.5%) as source materials, citric acid(99.5%) as a chelating agent, NH4F as N and F sources, and utilizes ammonium hydroxide to regulate the pH value, and dark blue sol is prepared, dried, calcined to obtain the N-F co-doped bismuth vanadate photocatalytic material. When the material is compared to bismuth vanadate without being doped, because of the synergistic effects of N and F, oxygen vacancies and V4+ with catalytic activity are increased N-F co-doped bismuth vanadate crystals, the band-gap energy is narrower and the photocatalytic activity is raised obviously in visible light. The method is advantaged by simple process, mild conditions and good repeatability. The photocatalytic material can be widely used in photocatalytic degradation of organic pollutants, and has wide application prospects in environmental governance.

The invention discloses a method for preparing a Bi/BiVO4 composite photoanode material by photodeposition. The method comprises the following steps: soaking a BiVO4 electrode in an ethylene glycol/water mixed solution of Bi(NO3)3 5H2O, and illuminating to uniformly generate a layer of an ash black film on the surface of the BiVO4 electrode; and washing with ethyl alcohol to obtain a Bi/BiVO4 composite photoanode. According to the method, metal Bi particles are successfully loaded on a multihole BiVO4 thin film in a simple photo-reduction process; furthermore, introduction of the metal Bi particles enlarges an absorption range of bismuth vanadate to visible light; meanwhile, electrons in the metal Bi particles are transferred onto a BiVO4 conduction band to increase the concentration of current carriers; and a hole in the BiVO4 surface in a pure Na2SO4 solution oxidizes part of the metal Bi nano particles, so that separation of electron-hole pairs is effectively promoted, and the photoelectric chemical decomposition performance of water is improved.

The invention discloses a carbon nitride nano particle modified pucherite composite photocatalyst and a preparation method thereof. Carbon nitride nano particles are dispersedly compounded on the surface of porous pucherite, and the porous pucherite is composed of bent pucherite nanorods; the preparation method comprises the steps of firstly, preparing carbon nitride powder, adding the carbon nitride powder to high-purity water and performing ultrasonic dispersion, adding bismuth nitrate pentahydrate and stirring until the mixture is dissolved completely, adding ammonium metavanadate and continuing to stir, carrying out centrifugal separation, washing and drying to obtain a solid sample, then performing heat treatment, and grinding into powder. According to the carbon nitride nano particle modified pucherite composite photocatalyst, the carbon nitride nano particles are small and are dispersedly compounded on the surface of the porous pucherite, so as to be beneficial to exposure of carbon nitride-pucherite interfaces with high activity and reduction of a charge transferring distance, and therefore, the carbon nitride nano particle modified pucherite composite photocatalyst has wide application prospect in the fields such as environment pollution control and energy; besides, the preparation method of the composite photocatalyst is simple, low in cost and good in repetitiveness, and can well meet the requirement of volume production.

The invention discloses a method for synthesizing monoclinic-phase bismuth vanadate photocatalyst powder by using a microwave hydrothermal synthesis technology. The method comprises separately dissolving bismuth nitrate pentahydrate (Bi(NO3)3.5H2O) used as a bismuth source and ammonium metavanadate (NH4VO3) used as a vanadium source in HNO3 and NaOH solution at a ratio of Bi to V of 1:1, and synthesizing monoclinic-phase BiVO4 powder at the reaction temperature of 160-220 DEG C and heat-insulation time of 60-120 minutes by using a microwave hydrothermal method. In the method disclosed by the invention, monoclinic-phase BiVO4 powder with photocatalytic activity is rapidly synthesized by using the microwave hydrothermal synthesis technology. The method simultaneously has the unique characteristics of microwave heating and the advantages of the hydrothermal method, the obtained powder has uniform particle size distribution, the process is simple and easy to control, the preparation period is short, the energy is saved and the obtained monoclinic-phase BiVO4 powder has very wide application prospects.

The present invention relates to a preparation method for a carbon nanotube-nano-bismuth vanadate composite photocatalyst. The method comprises: (1) adding a bismuth salt and a stabilizing agent to a phosphate buffer solution, stirring to form a suspension, dissolving metavanadate in the phosphate buffer solution, adding to the suspension, and stirring to form a transparent solution; (2) adopting an alkaline solution to adjust the pH value of the transparent solution to 6.0-8.0, adding carbon nanotubes while maintaining a temperature to 40-100 DEG C, stirring until uniformly mixing, centrifugating, filtering, washing, placing into a muffle furnace to carry out baking, and finally cooling and grinding to obtain the finished product. The preparation method of the present invention has characteristics of simpleness, easy performance, low requirements on equipment, and good operability. The prepared carbon nanotube powder bismuth vanadate is uniformly distributed, the persistent toxic substances can be efficiently degraded under the ultraviolet light condition and the visible light condition with the prepared carbon nanotube powder bismuth vanadate, the prepared carbon nanotube powder bismuth vanadate is convenient to use, and can be recovered and regenerated.

The invention relates to a preparation method of a pucherite/graphene compound photo-catalyst with a controllable particle size. The method comprises the following steps: dissolving bismuth nitrate and ammonium metavanadate precursor powder into a mixed reagent of glycerinum, alcohol and water to obtain a pucherite precursor solution; ultrasonically dispersing graphite oxide or a water solution or an alcoholic solution of the graphite oxide into the precursor solution; carrying out ultrasonic treatment, centrifugally filtering and drying in a drying oven; and finally preparing the pucherite/graphene compound photo-catalyst with the controllable particle size. Compared with the prior art, the obtained catalyst has the advantages of controllable particle size, and wide application prospect in the aspects of photocatalytic decomposition of organic pollutants and oxygen production employing photolysis of water.

The invention belongs to the technical field of semiconductor photocatalysis, and discloses a bismuth oxyiodide-bismuth vanadium oxide heterojunction photocatalyst and a preparation method thereof. The photocatalyst is a heterostructure formed by combination of bismuth oxyiodide ad bismuth vanadium oxide, and bismuth vanadium oxide nanoparticles are uniformly dispersed on bismuth oxyiodide nanoparticle surfaces. The preparation method comprises firstly dissolving bismuth nitrate pentahydrate and citric acid in diluted nitric acid and adjusting pH value, dissolving ammonium metavanadate and citric acid in distilled water and heating, and mixing the two solutions; and dissolving bismuth nitrate pentahydrate in glycol, dissolving potassium iodide KI in distilled water, mixing the two solutions and putting into the above mixed solutions, stirring, ageing, drying, calcining and grinding, so as to obtain the heterojunction photocatalyst. The synthesized photocatalyst possesses the typical heterostructure, possesses the characteristics of inhibiting electron-cavity recombination and effectively promoting carrier separation, and compared with a monomer bismuth vanadium oxide, the synthesized photocatalyst is relatively wide in photoresponse scope and relatively good in catalytic activity and stability.

The invention provides a crystal face proportion-controllable bismuth vanadate photocatalyst, and a synthesis method thereof. The photocatalyst is sued for high-efficiency photocatalysis of water oxidation. The growth process of the bismuth vanadate photocatalyst is controlled to accurately regulate the transition of the phase structure of the photocatalyst from a tetragonal phase to a monoclinic phase and the change of the monocrystalline morphology from a micro-spherical shape to a regular decahedral morphology, so the (010) and (011) proportions of the decahedron are effectively controlled. The aquatic product oxygen decomposition activity of the optimized decahedral bismuth vanadate photocatalyst in the presence of a Fe<3+> soluble electron acceptor reaches 60.0 L/kg/h or above, and the oxygen production apparent quantum efficiency at 460 nm reaches 60% or above. The photocatalyst still has good activity under outdoor sunlight, can be recycled multiple times, and has good stability. The method has a simple preparation process, and the prepared photocatalyst has the advantages of high activity, high stability, non-toxicity, greenness, realization of high-efficiency catalysis of the water oxygen under the sunlight, and hopefulness for being coupled with a hydrogen production catalyst in large-scale solar photocatalytic decomposition of water for producing hydrogen.