57results about How to "Improve visible light photocatalytic activity" patented technology

The invention provides a method for preparing sulfur and nitrogen co-doped titanium dioxide with visible light catalytic activity, which adopts a sol-gel method and comprises the following steps: hydrolyzing titanium ester and introducing sulfur and nitrogen sources to obtain a titanium dioxide sol, wherein the sulfur and nitrogen sources are from thiourea solution; in a sol system, dropwise adding 1 to 5 percent saturated aqueous solution of thiourea to perform the hydrolysis reaction to obtain the sol; then performing aging and volatilizing a diluent to obtain a titanium dioxide gel; drying the titanium dioxide gel and grinding into powders; performing heat treatment on the solid powder; and calcinating to obtain sulfur and nitrogen co-doped titanium dioxide nano powder. In the method, the thiourea is used as the raw materials of the nitrogen and sulfur sources, the sulfur and the nitrogen are simultaneously introduced in the process of the hydrolysis reaction of the sol to achieve synergistic effect and improve the reaction efficiency, raw material consumption is less, the process is simplified, the absorption range of visible light is effectively improved, the wavelength of the visible light is expanded to about 650nm, and the sulfur and nitrogen co-doped titanium dioxide has obvious visible light activity in the photocatalytic degradation reaction of organic pollutant molecules.

The invention proposes a kind of hydrothermal method used for preparing light catalyzing material with visible light active nano crystal Bi2WO6 powder. The method makes bismuth nitrate and sodium tungstate as raw materials, prepare them into mixed solution, then add into reacting kettle and have hydrothermal treatment for 10 - 48 hours at 100 - 200 Deg. C, take out reacting kettle, after the system cooled to room temperature, repeatedly wash the got output to neutral with deionized water, then dry in vacuum condition, finally through 100 -1000 heat treatment for 0.5 -10 hours, we can obtain light catalyzing material with visible light active nanometer crystal Bi2WO6 powder. The method has such advantages as low synthesizing temperature, large specific surface area of obtained simples and small grains. The prepared material can not only show light catalyzing activeness in ultraviolet, but also show light catalyzing activeness in visible light bound as sunlight or indoor lamplight.

The invention discloses a Bi/g-C3N4 semimetal-organic composite photocatalyst and a preparation method. The preparation method comprises the following steps: (11) mixing a precursor of a bismuth element and graphene-like carbide nitrogen according to the mass ratio of the bismuth element in the precursor to the graphene-like carbide nitrogen being 0.1%-250% so as to obtain a mixture; (12) adding the mixture into 1mol/L salpeter solution so as to obtain a mixture solution, and adjusting the pH value of the mixture solution to be 1-2; and (13) heating the mixture solution in a reduction system of a reducing solvent so as to obtain the Bi/g-C3N4 semimetal-organic composite photocatalyst by an in-situ precipitation method, wherein the temperature is 80-210 DEG C and the heating time is 1 hour-48 hours. The Bi/g-C3N4 semimetal-organic composite photocatalyst and the preparation method which are disclosed by the invention can be used for solving the problem of relatively high cost of the photocatalyst due to expensive precious metal in the prior art.

The invention discloses a preparation method for a snowflake-shaped ZnO/BiOI composite material. Firstly, Zn(NO3)3.6H2O and NaOH are dissolved in deionized water; then, lauryl sodium sulfate is dispersed into a mixed solution of absolute ethyl alcohol and deionized water; and next, the two solutions are mixed, and after magnetic stirring is carried out, a microwave-assisted hydrothermal method is adopted, and the flower-shaped ZnO nanorods are obtained. KI and Bi(NO3)3.5H2O are added into ethylene glycol, after a period of magnetic stirring, the prepared flower-shaped ZnO nanorods are added, ultrasonic dispersion is added, and after a solvothermal reaction, the flaxen snowflake-shaped ZnO/BiOI composite material is obtained. Compared with other shapes, the snowflake-shaped ZnO/BiOI composite material is a tightly-stacked laminar BiOI sphere formed on the surfaces of the ZnO nanorods, and the photocatalytic activity is remarkably improved. By means of the solvothermal method, the reaction time and the reaction temperature are controlled easily, equipment is simple, and the cost is low.

The invention discloses a graphene/antimony sulfide composite photocatalyst preparation method. The method comprises adding graphene oxide into deionized water, carrying out ultrasonic dispersion, adding a sulfur source into the solution, carrying out ultrasonic treatment, adding antimony potassium tartrate into the solution, carrying out magnetic stirring to obtain a reaction mixture, carrying out hydro-thermal treatment on the reaction mixture, carrying out cooling, carrying out centrifugation to obtain black precipitates and washing and drying the black precipitates to obtain the graphene/antimony sulfide composite photocatalyst. The graphene/antimony sulfide composite photocatalyst has good compounding effects and high visible light photocatalytic activity and fully utilizes sun lights and indoor natural lights to realize photocatalytic degradation of environment pollutants. The preparation method has the advantages of simple processes, production process environmental friendliness, easy control of reaction parameters, low enforcement cost and excellent product quality and can be widely used for preparation of a graphene-based composite material.

The invention provides a preparation method of a flower-like BiOCl photocatalyst, the prepared BiOCl photocatalyst and application of the BiOCl photocatalyst. The method comprises the following steps: (1) adding bismuth nitrate and maltose into water, dripping a chloride solution, and stirring to form a bismuth precursor, wherein a molar dose ratio of the bismuth nitrate to maltose is 1:(0.2-3); (2) regulating the pH value of the bismuth precursor to be 5.0-6.5 by adopting an alkaline solution so as to form reactants; (3) reacting the reactants at the temperature of 150-160 DEG C for 24-30 hours so as to obtain a precipitate; (4) washing and drying the obtained precipitate in the step (3), thereby obtaining the BiOCl photocatalyst with a flower-like structure. According to the method disclosed by the invention, the defects in the preparation method of the conventional BiOCl photocatalyst are overcome, the obtained BiOCl photocatalyst is capable of well responding to visible light and has high visible light photocatalytic activity as well as excellent stability and reusability.

The invention provides a preparation method of a rutile type boron-doped titania (B-TiO2) microsphere with an exposed high energy crystal face {001} and belongs to the technical field of the preparation of inorganic material. The preparation method comprises the following specific steps: adding titanium boride (TiB) into a hydrochloric acid solution hydrazine containing natrium fluoride (NaF) to obtain a mixed solution, forcefully agitating, then transferring the mixed solution to a reactor with a polytetrafluoroethene lining, keeping the mixed solution at a constant temperature of 200 DEG C for 12-24 hours, naturally cooling the mixed solution to the room temperature so as to obtain a product, filtering the product, respectively washing and settling the product with distilled water and absolute ethyl alcohol for three times, drying the product at a temperature of 60-80 DEG C for 12-24 hours, and finally preparing the B-TiO2 microsphere with the exposed high energy crystal face {001}, of which exposing rate nearly reaches 100 percent. The preparation method is simple in preparation technology and good in repeatability; the prepared B-TiO2 microsphere is controllable and uniform in size and has a diameter of 3-5 micron; the element boron is doped, and is uniform in distribution and controllable in the amount of dopping; in addition, the prepared B-TiO2 microphere has excellent visible light catalytic activity, and is likely to be widely applied in the fields of photolytic water hydrogen preparation, organic contaminant degradation and the like.

The invention provides a solvent-heat preparing method of N-doped TiO2, comprising: adding TiO2 into the solvent of N-containing organic alkali and water or alcohol, ultrasonic vibrating, pouring the mixture into a corrosion-resistant stainless steel hydrothermal reactor at room temperature, raising temperature to make solvent heat reaction, filtering, washing and drying and making it. And the invention overcomes the aggregation growth in the high temperature gas-phase reacting course, directly adopts TiO2 to one-step synthesize it by simple solvent heat synthesis process. And it has good dispersivity, small and uniform particles, high nitrogen doping quantity, high catalytic activity in the sun, etc.

The invention provides a preparation method of a self-doped titanium dioxide nanorod. The method comprises the following steps of: adding butyl titanate [Ti(OC4H9)4] into liquor of hydrazine (N2H4.H2O) and ethylene glycol (C2H6O2); powerfully stirring; then, transferring to a reaction kettle lined with polyvinyl fluoride; maintaining the constant temperature at 200 DEG C for 12-24 hours; naturally cooling to room temperature; and filtering, washing and drying to obtain the self-doped titanium dioxide nanorod provided by the invention. According to the method provided by the invention, self-doped titanium dioxide is directly reduced in a liquid phase without thermal reduction treatment. The preparation method is simple in process, and the self-doped TiO2 nanorod is controllable in size and uniform in dimension, and the average length is 50-80nm and the average diameter is 8-15nm. The self-doped titanium dioxide nanorod prepared by the method provided by the invention is expected to be widely applied to the fields of hydrogen generation by photolysis of water, degradation of organic pollutants and the like.

The invention discloses a preparation method of a Fe-doped Bi2O2CO3 photocatalyst and the Fe-doped Bi2O2CO3 photocatalyst, and belongs to the technical field of photocatalysis. The preparation methodcomprises the following steps: uniformly mixing a dopant containing Fe<3+> in alkaline solvent solution with dissolved Bi(NO3)3 and sodium citrate, and carrying out hydrothermal reaction under the condition of containing ammonia water. The photocatalyst is prepared according to the preparation method. The Fe-doped Bi2O2CO3 photocatalyst disclosed by the invention has the advantages that Fe can bedoped into lattices of Bi2O2CO3, and the absorption of Bi2O2CO3 for visible light can be improved, so that the photocatalytic activity of Bi2O2CO3 for the visible light is improved.

A method of preparing a macroporous/mesoporous stannic sulfide/titanium dioxide photocatalyst is disclosed. The method includes steps of adding absolute ethanol into butyl phthalate, adding tin tetrachloride into the abovementioned solution, and labeling the solution as an A solution, preparing a sodium sulfide solution that has a certain concentration and that is labeled as a B solution, adding the A solution dropwise into the B solution, allowing the mixture to stand for 24 h, transferring the prepared precipitate and solution into a hydrothermal kettle, maintaining the temperature at 180 DEG C for 3-9 h, cleaning the precipitate after hydrothermal treatment, and drying to obtain the macroporous/mesoporous stannic sulfide/titanium dioxide composite photocatalyst. The composite photocatalyst prepared by the method has good visible light photocatalytic activity and can rapidly degrade organic pollutants under visible light.

The invention discloses a preparation method of a defective titanium dioxide/ultrathin carbon nitride/defective titanium dioxide Z-type heterojunction photocatalyst, and belongs to the field of photocatalytic water treatment. Comprising the following steps: 1, preparing TiO2 nanoparticles by a sol-gel method; 2, carrying out secondary high-temperature calcination to obtain thin g-C3N4/; 3, carrying out ball milling and compounding to obtain TiO2-x/ultrathin g-C3N4/TiO2-x of a sandwich structure; and 4, carrying out solid-phase reduction to obtain the final defective titanium dioxide/ultrathin carbon nitride/defective titanium dioxide Z-type heterojunction photocatalyst. According to the preparation method of the defective titanium dioxide/ultrathin carbon nitride/defective titanium dioxide Z-type heterojunction photocatalyst, oxygen vacancies are introduced to broaden the light absorption range of the catalyst, a sandwich structure is constructed to increase space conduction and separation of photon-generated carriers, the Z-type heterojunction improves the ability of the photocatalyst to generate strong oxidizing species, and the photocatalytic activity of the photocatalyst is improved. Therefore, the activity and stability of the photocatalyst are stimulated in multiple aspects, and tetracycline or other types of pollutants in water are effectively removed.

The invention discloses a novel photocatalytic material based on Cu and Ag. The material can be expressed by CuxAg(1-x)/(CuyAg(1-y))2O/Ag3PO4/TiO2, wherein 0<x and y<=1. Based on the preparation of TiO2 nanowires by a hydrothermal method, the novel photocatalytic material CuxAg(1-x)/(CuyAg(1-y))2O/Ag3PO4/TiO2 with a large specific surface area is obtained by modifying CuxAg(1-x), (CuyAg(1-y))2O nanoparticles and bulk Ag3PO4. The novel photocatalytic material has good photocatalytic performance.

The invention relates to a method for selectively modifying the {110} surface of bismuth vanadate with a NiOOH assistant. The method comprises the following steps: 1) preparing an electrolyte solution; 2) adjusting the pH value of the electrolyte solution prepared in step 1) to 2-12; 3) mixing the solution obtained in step 2) with a Pt/BiVO4 powder to form a uniform suspension; 4) adding a water-soluble nickel salt to the suspension obtained in step 3); 5) uniformly stirring the suspension in step 4) at room temperature, and illuminating the suspension for a certain period of time; and 6) filtering, washing and drying a precipitate obtained in step 5) to obtain a photocatalyst selectively modified with the NiOOH assistant. The synthesis method has the advantages of simplicity in operation,greenness, environmental protection, energy saving, and no need to add various organic surfactants, and the nickel oxyhydroxide has the advantages of wide sources of raw materials, low price, no toxicity, no pollution and stable chemical properties.

The invention relates to a method for preparing fluorine and tungste co-doped anatase type nano titanium dioxide composite powder, which is characterized by comprising the following steps: 1) preparing butyl titanate, absolute ethanol, acetic acid, HF, deionized water and ammonium tungstate according to a ratio of 20mL:200mL:5mL:(0.1 to 0.15mL):5mL:(85-340g), mixing and uniformly stirring the absolute ethanol and the acetic acid to obtain mixed liquid and dripping the butyl titanate into the mixed liquid to obtain yellowish sol; 2) preparing solution of fluorine and tungsten; 3) adding F-W-H2O into the yellowish sol to obtain milky sol, and standing the milky sol for 2 to 3 days; and 4) washing the milky sol which is stood for 2 to 3 days with deionized water till the pH value is 7, filtering to obtain a precipitate and drying to obtain the fluorine and tungste co-doped anatase type nano titanium dioxide composite powder. The method has the characteristics of low cost and simple preparation process and can realize batch production, and the prepared fluorine and tungste co-doped anatase type nano titanium dioxide composite powder has the characteristics of high catalytic activity and the like.

The invention relates to a composite photocatalyst, a preparation method of the composite photocatalyst, and a photocatalytic hydrogen production method. The composite photocatalyst is prepared by thefollowing steps: modifying graphite phase carbon nitride by adopting barium niobate nanosheets, and preparing the graphite phase carbon nitride-barium niobate composite photocatalyst. The 3d track ofniobium participates in composition of the valence band, so that the conduction band is enriched in free electrons; due to the diversity of the crystal structure and electron structure, the barium niobate has an appropriate energy band structure and high photo-induced carrier mobility; in addition, the graphite phase carbon nitride is modified by the barium niobate nanosheets, so that heterojunctions are produced between the barium niobate nanosheets and the graphite phase carbon nitride. Due to the special energy band structure produced by the heterojunctions and the carrier transport characteristics, the graphite phase carbon nitride-barium niobate composite photocatalyst having the heterojunction structure is capable of effectively inhibiting compounding of the photo-induced electron holes in a light-catalyzed reaction, and the quantum efficiency is improved. Therefore, the graphite phase carbon nitride-barium niobate composite photocatalyst has excellent visible light photocatalytic activity.