1961 results about "Photocatalytic degradation" patented technology

The present invention relates to Ag and RE doped nanometer zinc oxide and its preparation process and application in photocatalysis to degrade organic matter and killing bacteria. Ag, RE metals La, Ce, Pr, Nd, Sm, etc. are doped into nanometer zinc oxide to raise its photocatalytic activity in degrading harmful chemical matter and resisting bacteria. Under lighting, the doped nanometer zinc oxide has higher photocatalytic activity and higher antibacterial capacity; and in case of no lighting, it has relatively high antibacterial effect owing to the antibacterial effect one Ag, Zn, RE and other antibacterial ions. The preparation process may be an organic matter complexing process or a sprying pyrolysis process. The doped nanometer zinc oxide may be used through mixing with other material, or used as additive added into plastic, ceramic, fiber, timber, rubber, glass, cement, metal and other material to form various kinds of photocatalytic antibacterial material and product.

The invention relates to a high-capacity intermittent industrial wastewater microwave photocatalytic degradation device, belonging to the technical field of wastewater treatment. The existing microwave photocatalytic degradation technology for the organic pollutant-containing industrial wastewater has the problems that microwave energy is wasted and practical single-jar wastewater treatment quantity is relatively small, and has the problem of scaling since an electrodeless ultraviolet lamp screen protector in the device is soaked in wastewater liquid by the outer side face of a quartz tube for a long term. The invention intends to solve the problems globally.In order to solve the problems, an electrodeless ultraviolet lamp is arranged in a silk screen cage-shaped nonopaque microwave restraining device made from metal material, the microwave is guided into the microwave restraining device to be restrained, the useless dissipation of the microwave can be stopped, and the designed volume of an expander can be allowed to be greatly enlarged on the basis of the structure, so that the single-jar wastewater treatment quantity of a reactor can be greatly improved. An ultrasonic transducer is attached to the outer side face of the side wall of the reactor, so that the scale can be timely removed after the high-frequency ultrasonic wave reaches up to the scale.

The invention belongs to the field of photocatalytic materials, in particular relates to a novel red light or infrared light catalytic material which comprises an up-conversion material and a semiconductor material. In the invention, a semiconductor photocatalytic material and a red light/infrared-ultraviolet up-conversion luminescent material are combined, and the up-conversion material is used for absorbing red light/infrared light and emitting ultraviolet light, thereby activating the semiconductor photocatalytic material and realizing the infrared light catalysis. By modifying and improving the semiconductor in the composite material, the photocatalytic activity of the material can be further improved. The invention expands the wavelength range of the excitationlight required by photocatalytic reaction, breaks the limit that the photocatalytic reaction can be activated only by ultraviolet light and shortwave visible light, improves the utilization ratio of sun light in the photocatalytic reaction, and can be widely applied to the photocatalytic degradation of organic pollutants in water by using red light, infrared light and sun light.

The invention relates to a preparation method of a noble metal modified titanium dioxide photocatalyst, which refers to a photo-catalytic oxidation-reduction coupling method realized in a photo-catalytic reactor: firstly, TiO2, noble-metal water soluble salt and organism are used for preparing a suspension which is then ultrasonically vibrated after the pH value is regulated to 1-12, put into a photo-catalytic reactor for reaction for 0.5h to 8h at 0 DEG C to 90 DEG C under the irradiation of an ultraviolet source with the power of 8W to 125W or a medium or high-voltage mercury lamp source with the power of 100W to 600W, and then separated, washed and dried to obtain the TiO2 photocatalyst modified by noble metal Ag, or Au, or Pt or Pd, wherein, the content of TiO2 is 90 percent to 99.99 percent, the content of the noble metal is 0.01 percent to 10 percent. The noble metal modified titanium dioxide photocatalyst has high photocatalytic degradation activity and strong surface hydrophobicity and the attached catabolites are easy to clean.

The present invention discloses a method for preparing heteroatom doped carbon quantum dot, and application thereof in fields of biomedicine, catalysts, photoelectric devices, etc. The various kinds of heteroatom doped carbon quantum dots are obtained by using a conjugated polymer as a precursor and through a process of high temperature carbonization. These carbon quantum dots contain one or more heteroatoms selected from the group consisting of N, S, Si, Se, P, As, Ge, Gd, B, Sb and Te, the absorption spectrum of which ranges from 300 to 850 nm, and the fluorescence emission wavelength of which is within a range of 350 to 1000 nm. The carbon quantum dot has a broad application prospect in serving as a new type photosensitizer, preparing drugs for photodynamic therapy of cancer and sterilization, photocatalytic degradation of organic pollutants, photocatalytic water-splitting for hydrogen generation, organic polymer solar cell and quantum dot-sensitized solar cell.

The invention relates to permeable bricks inlaid with nanometer titanium dioxide and a preparation method thereof and belongs to the field of building materials. According to the preparation method provided by the invention, titanium dioxide precursor turbid liquid is evenly sprayed into holes of permeable brick base bodies, and then the permeable brick base bodies are dried and calcined for 10-30 min so as to obtain the permeable bricks inlaid with nanometer titanium dioxide and anatase type nanometer titanium dioxide is uniformly inlaid in the holes of the obtained permeable bricks. The permeable bricks can effectively degrade contaminants in water seepage passing though the permeable bricks and some organic contaminants attached to the surfaces of brick bodies in a manner of photochemical catalysis and also can degrade a part of gaseous pollutants in air in a manner of photochemical catalysis.

The invention relates to a novel composite air purification coating material and a preparation method thereof and belongs to the technical field of environment-friendly functional coating and air purification. Aerogel and photocatalysts are used as adsorption/photocatalytic functional fillers in the coating, prepared adsorption/photocatalyst dispersion liquid and acrylic emulsion or fluorocarbon emulsion are mixed, and an appropriate quantity of dispersing agents, coalescing agents, defoaming agents and the like are added so as to obtain the novel composite air purification coating. Compared with air purification coatings in prior art, the novel composite air purification coating is efficient and permanent in air purification effect. The test result of adsorption/photocatalytic degradation of formaldehyde shows that the formaldehyde concentration is decreased from 0.39mg/m3 to 0.04 to 0.05mg/m3 after 5 to 6 hours of adsorption/photocatalytic degradation, and the adsorption/photocatalytic degradation rate reaches to 79.49% to 89.74%.

The present invention provides a novel visible catalyst-silver phosphate and a preparation method thereof, solving the problems of wide TiO2 forbidden band, no absorbability of visible weakness, and the like in the prior art and applying Ag3PO4 to the field of photocatalysis for the first time. In the invention, a silver ammonia solution for replacing a silver nitrate solution is used as a silversource, the reaction of silver ions and phosphate ions is slowed, and then the catalyst is obtained and has the effect of high-efficiency photocatalytic degradation. The preparing method of the invention is simple and is favorable to extensive popularization.

The invention relates to the technical field of nanometer materials and photocatalytic degradation of organic pollutants, and in particular relates to a Bi/BiOCl (bismuth oxychloride) composite photocatalyst as well as an in-situ reduction preparation method and application thereof. Bi nano-particles with particle sizes of 5-20nm are uniformly distributed on a BiOCl nanosheet with 100-600nm or a the surface of a BiOCl microsphere being 1-3 microns to obtain the Bi/BiOCl composite photocatalyst; the Bi/BiOCl composite photocatalyst is prepared by gaseous-phase in-situ reduction or liquid-phase in-situ reduction; as Bi nano-particles are formed on a BiOCl substrate in an in-situ manner, the lattice matching degree of interfaces between the Bi and the BiOCl is high and the charge migration is facilitated; the Bi nano-particles have the good dispersibility, are difficult to cause agglomeration, and have the good size and distribution controllability; the Bi nano-particles can be well combined with the BiOCl and are difficult to drop off, the photo catalytic capability of the BiOCl under the existence of ultraviolet light can be improved, the spectral response range is expanded, and the visible photo catalytic capability can be acquired, and the Bi/BiOCl composite photocatalyst can be effectively applied to photocatalytic degradation of organic pollutants in a water body.

The invention relates to a composite material with anti-bacterial and purifying functions and a preparation method of the composite material, and belongs to the technical field of environmental-friendly materials. The composite material with the anti-bacterial and purifying functions comprises raw materials in parts by weight as follows: 70-95 parts of a mineral composite adsorption material, 3-25 parts of a photocatalytic degradation material, 2-15 parts of a rare earth inorganic anti-bacterial material and 1-10 parts of an additive, wherein the mineral composite adsorption material is prepared from sepiolite, diatomite, medical stone and attapulgite; the photocatalytic degradation material is prepared from titanium oxide, tourmaline and far infrared ceramic powder; the rare earth inorganic anti-bacterial material is prepared from zinc oxide, cerium oxide and silver oxide; the additive is a mixture of activated carbon, carboxymethylcellulose and pumice powder. The composite material with anti-bacterial and purifying functions has high adsorption and decomposition rate, can be resistant to water and damp and has excellent anti-bacterial effect. Meanwhile, the invention provides the preparation method. According to the preparation method, the cost is low, the amount of produced wastewater is low, and powder is simple and convenient to apply.

The invention relates to an omnidirectional antibacterial intelligent type air purifier for a vehicle, which comprises a shell, an air purification component, a fan power component, an energy component, an induction sensor component, a negative-ion generator and a display intelligent control component. The omnidirectional antibacterial intelligent type air purifier for the vehicle uses a nano silver modified titanium dioxide as a photocatalyst, thereby increasing photocatalysis effect and sterilization antibacterial performance. The omnidirectional antibacterial intelligent type air purifier for the vehicle uses an ultraviolet light emitting diode as a ultraviolet light source, thereby guaranteeing the photocatalyst to be capable of playing the role of degrading pollutants efficiently. The inner surface and the outer surface of an enclosure all have antibacterial performance, thereby guaranteeing bacteria not to live on the surface of an airframe of the omnidirectional antibacterial intelligent type air purifier for the vehicle, and guaranteeing personal safety. The omnidirectional antibacterial intelligent type air purifier for the vehicle can automatically induct air conditions, adjusts purification power in real time, and has intelligent control function.

The invention discloses a method for preparing concavo-convex rod soil/zinc oxide nanometer composite materials, which comprises the following steps: purifying and dispersing the concavo-convex rod soil in water to prepare concavo-convex rod soil dispersion liquid; then adjusting the temperature of the concavo-convex rod soil dispersion liquid to 30 to 100 DEG C; agitating the concavo-convex rod soil dispersion liquid dispersion liquid and while adding zinc salt aqueous solution with the concentration of 0.3 to 3 mol.L<-1> and carbonate aqueous solution with the concentration of 0.3 to 2 mol.L<-1> to the concavo-convex rod soil dispersion liquid dispersion liquid; and keeping the pH value of mixed liquid within the range of 6.0 to 8.0. The prepared mixed serous fluid comprising the prepared nanometer concavo-convex rod soil and basic zinc carbonate is filtered; and a filter cake is washed by deionized water; when the electrical conductivity of filtrate is less than 300 MuS.cm<-1>, the washing is finished; and the filter bake obtained is dried at the temperature of below 100 DEG C, then baked for 1 to 10 hours at the temperature of 300 to 600 DEG C, and finally crushed. The invention is simple and has the advantages of low energy consumption and high safety; the load of the adsorbing material prepared is uniform and has good dispersibility, strong adsorbability and remarkable photo-catalyzed degradation property.

The invention discloses a preparation method of a chitosan/titanium dioxide composite material. The chitosan is dissolved in colloid titanium dioxide solution containing acetic acid or the chitosan is blended with the colloid titanium dioxide after being dissolved by the acetic acid, by stirring, the dioxide is homogeneously dispersed in TiO2 colloid solution, and homogeneous chitosan/TiO2 mixed solution is prepared. The mass weight percentage of the chitosan in the mixed solution is 1 to 10 percent, and the mass weight percentage of TiO2 is 0.5 to 20 percent; the chitosan/titanium dioxide composite material is consolidated and prepared after the mixed solution is degassed. The compound membrane prepared by the method is transparent or semitransparent. The preparation method of the invention is simple, the raw material is inexpensive, the material source is abundant, and TiO2 is distributed in the compound material at nano-size. The prepared product has wide application range, and has photocatalysis degradation characteristic on waste water of helianthine and other dye, etc. The composite material can be taken as an indoor air purifying agent, an industrial waste water treating agent, an antibacterial film, self-cleaning fiber and antibacterial fiber, etc.

The invention relates to a silver doped grapheme-zinc oxide nano composite photocatalytic material and a method for preparing the same and belongs to the technical field of nano composite materials and photocatalysis. Graphite oxide is subjected to ultrasonic dispersion to obtain a dispersion solution of graphene oxide; precursors of silver ions and zinc ions are added in the dispersion solution of the graphene oxide, and the mixture is placed into a reaction kettle to be subjected to hydro-thermal treatment to be prepared into the silver doped grapheme-zinc oxide nano composite photocatalytic material in situ after the pH is regulated to an alkaline condition. Photocatalytic degradation experiments show that the silver doped grapheme-zinc oxide nano composite photocatalytic material prepared through the method has good adsorption and visible light photocatalytic degradation effects on rhodamine B and is an ideal nano composite photocatalytic material.

The invention relates to a silver-modified carbon nitride composite photocatalytic material and a preparation method thereof. The preparation method comprises: dissolving dicyanodiamide or melamine in deionized water or dimethyl sulfoxide and performing ultrasonic dispersing, so as to obtain a dicyanodiamide or melamine dispersion liquid; dissolving silver nitrate in deionized water and stirring uniformly, so as to obtain a silver nitrate solution; slowly dropwise adding the silver nitrate solution into the above dicyanodiamide or melamine dispersion liquid under the condition of magnetic stirring, and continuing stirring the solution, so as to obtain a mixed precursor solution; using anhydrous ethanol and deionized water repeatedly wash the obtained mixed precursor solution for multiple times, and performing vacuum drying; and putting the obtained product in a proper crucible and covering, putting in a high-temperature furnace, and sintering for a period under the condition of nitrogen protection, so as to obtain a powdery sample. The advantages comprise that the raw material source is wide, the preparation technology is simple and practicable, and the cost is relatively low; and the prepared composite photocatalytic material has relatively good photocatalytic degradation effect on organic dye rhodamine B under irradiation of visible light.

The invention relates to a bismuthyl carbonate micro flowery material with a graded structure, which is structurally characterized in that two-dimensional nano flakes are staggered to form a flower shape, and the average diameter of the flakes is 3 to 4 microns. The material is prepared by fist dissolving bismuth nitrate into dilute nitric acid and then gradually dripping the dilute nitric acid into excessive sodium carbonate solution and reacting the solution. A preparation method can be implemented at the low temperature and the normal pressure, and has the advantages of short time consumption, low cost, simple equipment, easy operation and large-scale production. Because of a large specific surface area, the prepared bismuthyl carbonate micro flowery material with the graded structure has important practical application in the aspects of pharmacy and sterilization; and meanwhile, the material with the large specific surface area has good performance in the aspect of degrading organic pollutants by photocatalysis.

The invention relates to a self-repairing water-based super-hydrophobic coating. The durability aim of the surface performance of an existing super-hydrophobic coating is achieved, and the environment-friendly aim in the preparing process of a traditional super-hydrophobic coating is further achieved. The coating is prepared from, by weight, 10%-50% of aqueous film-forming resin, 5%-40% of microcapsule, 0.1%-10% of photocatalytic activity nanometer particles, 5%-40% of hydrophobicity nanometer particles and 10%-60% of deionized water. After the surface of the coating is subjected to physical abrasion or organic pollution, the microcapsule in the coating is fractured under the effect of photocatalytic degradation and releases fluoroalkyl silane, and the damaged surface is self-repaired, the super-hydrophobic performance of the coating is recovered, and therefore the durability when the coating is used outdoors is guaranteed. According to the self-repairing water-based super-hydrophobic coating, the method is simple, the preparing technology is environmentally friendly, and large-area construction is easy to achieve.

The invention discloses a preparation method and application of a hierarchical pore metal-organic framework loaded heteropolyacid catalyst. The catalyst adopts hydrothermal-extraction method for preparation. The method includes: dissolving an organic ligand, a template agent, a metal salt and Keggin type heteropolyacid in a solvent, conducting hydrothermal synthesis of a crystal product, and thenperforming Soxhlet extraction to obtain a catalyst. The obtained catalyst has a meso-micro hierarchical porous structure, realizes high dispersion of the active component heteropolyacid and ultra-highloading capacity, and at the same time solves the problems of large mass transfer resistance, long diffusion path and small reaction place in microporous materials. The catalyst provided by the invention shows excellent catalytic performance in both photocatalytic degradation of dye wastewater and catalysis of oxidation-extraction desulfurization reaction, the catalysis reaction uses visible light and hydrogen peroxide respectively, the process is clean, environment-friendly and green, and after repeated use, the catalyst still maintains high activity, and has high industrial application value.

The invention belongs to the fields of environmental science and engineering, and in particular relates to a method for preparing a bismuth ferrite photocatalyst capable of efficiently degrading organic pollutants in water by utilizing photocatalysis technology. The photocatalyst bismuth ferrite is synthesized by a solvent method; and during synthesis, a molar ratio of bismuth nitrate to ferric nitrate is 12:1, a xenon lamp is taken as a light source, and the bismuth ferrite is fully mixed with neural red solutions with different concentrations to photo-catalyze and degrade the neutral red dye in aqueous solution. The invention provides a high-efficiency method for removing the neutral read dye from the water. The method can remove over 70 percent of the neutral red dye (the concentration is 10 to 30 milligrams/liter) from the water in 2 hours; moreover, the photocatalyst has the advantages of simple preparation process, large particle size and easy recycling; and the method has the advantages of easy operation, low cost, high efficiency, time conservation, and good industrial application prospect.

The invention discloses a preparation method of a visible-light activated cuprous oxide/titanium dioxide nano-composite photocatalyst and applications thereof, belonging to the technical field of environmental pollution control. The preparation of the catalyst comprises the following steps of: 1) carrying out electrochemical oxidation reaction under the action of hydrofluoric acid with the concentration of 0.2 percent by weight for preparing a titanium dioxide nanotube electrode, wherein the tube diameter of a nanotube is about 80nm, and the tube length is 550nm; and 2) adopting a photoreduction chemical method to prepare the cuprous oxide/titanium dioxide nano-composite photocatalyst. The prepared composite photocatalyst has the advantages of simple synthesis, stable performance, the synthesis process belonging to the field of green chemistry and the like. The composition of cuprous oxide can not only reduce the defect of high composite probability of photoproduced electron-hole pairs, but also expand the light response range of the titanium dioxide nanotube electrode and further improve the photocatalytic degradation efficiency thereof to organic pollutants in the visible light range, thereby having very high practical value and application prospect.

The invention provides a nanofiber membrane. The nanofiber membrane is made of mixture by spinning. The mixture includes polymers and nanofiber materials in the mass ratio of 1:(0.01-0.2). The nanofiber materials are composed of photocatalyst and adsorbent. The adsorbent and the photocatalyst are used in the nanofiber membrane, the adsorbent can adsorb harmful gas in an adsorption chamber, the photocatalyst is capable of degrading and adsorbing harmful organics in holes of the adsorbent into carbon dioxide and water under the condition of indoor light rays and irradiation of a daylight lamp, and activates and regenerates the adsorbent in situ when decomposing the harmful organics on the adsorbent in the meantime, so that the adsorbent and the photocatalyst are reusable, and the nanofiber membrane has excellent air purification capacity. The invention further provides a preparation method of the nanofiber membrane and a nanofiber composite and a preparation method thereof.

The present invention discloses an antimicrobial agent by using nano titanium dioxide as carrier and making antimicrobial metal ions be attached to the nano titanium dioxide carrier. Its grain size is less than 100 nm, and its preparation method includes the following steps: soaking nano titanium dioxide, utilizing ultrasonic wave to disperse titanium dioxide soaking liquor, then adding metal salt containing antimicrobial metal ions, mixing them and dissolving them, fully stirring, making solid-liquid separation to obtain solid material, drying, roasting and grinding so as to obtain the invented product.

The invention belongs to the technical field of membrane and relates to a photocatalytic composite ceramic separation membrane using porous ceramic membrane as a carrier, a method for preparing the same and application of the separation membrane. The method is characterized in that a porous ceramic membrane substrate is used as the carrier to prepare hydroxyapatite sol and argent-titania composite sol through sol-gel technology; and a carrier membrane is subjected to secondary sol-gel dipping, drying and roasting sequentially to obtain the argent-carried titania/hydroxyapatite photocatalytic composite ceramic separation membrane with aperture of between 100 and 1,900 nm and porosity of between 20 and 55 percent. The photocatalytic composite ceramic separation membrane has biological adsorption and high photocatalytic activity and membrane permeability, improves separation of the composite membrane, photocatalytic degradation and sterilization, has remarkable effects of decontamination and sterilization, reduces the loss of porosity in the process of membrane preparation, has a simple preparation and application process, is easy for large-scale industrial production, integrates three units of membrane separation, photocatalytic degradation and sterilization and reduces investment and occupied area.

New magnetic dye-adsorbent catalyst has been described in this invention, which is the modification of conventional magnetic photocatalyst. The catalyst consists of a composite particle having a core-shell structure, with a magnetic particle as a core and a dye-adsorbent (which may also exhibit photocatalytic activity) as a shell. The shell is made up of 1-dimensional (1-D) nanostructure, which enhances the specific surface-area of the conventional magnetic photocatalyst. The new magnetic dye-adsorbent catalyst removes an organic dye from an aqueous solution via surface-adsorption mechanism; while, the conventional magnetic photocatalyst uses the photocatalytic degradation mechanism.

The invention provides a composition for use in degradable plastics, which comprises: 1) a visible light catalytic oxidation degradation and thermally catalytic oxidation degradation component which is metal organic compound of a transition metal and accounts for 1 to 10 percent of the total weight of the composition; 2) an ultraviolet light catalytic degradation component which is a nano transition metal compound which has a particle diameter of between 5 and 100 nanometers and an ultraviolet light catalytic degradation function and accounts for 0.1 to 10 percent of the total weight of the composition; 3) an assisted oxidation degradation component which accounts for 1 to 10 percent of the total weight of the composition; and 4) a plastic basic component which accounts for the balance ofthe total weight of the composition. The invention also relates to the use of the composition in the production of degradable plastic products and the various degradable packaging or dispensable plastics and plastic products produced by using the composition.

The invention relates to a titanium dioxide nanometer tube electrode in the technology field of fathering the environmental pollution and its preparation method as well as its application. Its features lie in: choose the pure titanium or titanium alloy as the substrate, carry out the electrochemical oxidation in the condition of hydrofluoric acid with its density between 0.01wt% and 0.5wt%, form a titanium dioxide nanometer tube with its diameter between 40nm and 100nm and its length between 20nm and 50nm on the substrate vertically and get the integrative titanium dioxide nanometer tube electrode. The preparation features lie in: choose the substrate as the anode after grinding, etching and drying and the platinum sheet as the cathode, control the distance between the two electrodes between 10mm and 50mm, put them into the reactor, power on the stabilized voltage power supply with it voltage between 15V and 25V, after 1-to-30-minute reaction calcine them at the temperature of 400deg.C to 600deg.C for 40nin to 80min, cool it in natural condition and get the titanium dioxide nanometer tube electrode. The titanium dioxide nanometer tube electrode can be applied to the photocatalysed degradation and photoelectroncatalysed degradation to the organic pollutants. It has larger surface area and simple preparation method.

The invention relates to a wastewater-degradation microwave photocatalytic device beneficial to inhibiting energy unnecessary dissipation, belonging to the technical field of wastewater treatment. The invention aims to totally solve the problem of energy unnecessary dissipation since the wastewater body absorbs abundant microwave energy, and the problem of scaling on the outer side surface of the quartz tube for an electrodeless ultraviolet lamp shield in the existing microwave photocatalytic degradation technique of industrial wastewater containing organic pollutants. The electrodeless ultraviolet lamp is arranged in a metallic wire-cage-shaped transparent microwave restrictor, microwaves are introduced into the microwave restrictor, so that the microwave restrictor can inhibit the microwave from unnecessary dissipation. On the basis of the structure, the design volume of the reactor is allowed to be greatly expanded, thereby greatly enhancing the single-tank wastewater treatment capacity of the reactor; and an ultrasonic transducer is arranged on the inner side surface of the side wall of the microwave photocatalytic reactor, thereby instantly clearing the scales under the action of high-frequency ultrasonic by using the ultrasonic transmission of the liquid medium.

Provided is a visible active photocatalyst of formula BiOX wherein X=P or S and process of preparation and use thereof. Use of the catalyst is demonstrated in the photocatalytic degradation of pharmaceutical drug pollutants and pollutant dyes using solar radiation or artificial radiation.

The invention discloses a preparation method of a TiO2 (titanium dioxide) mesoporous monocrystal microsphere and g-C3N4 heterojunction photocatalyst and belongs to the technical field of photocatalysis materials. The method comprises the following steps: putting g-C3N4 into a TiO2 seed crystal solution, and performing water bath treatment in water with the temperature of 60-90 DEG C to plant a seed crystal; adding g-C3N4 and a TiO2 precursor solution for preplanting the seed crystal into one of water, isopropanol or tertiary butanol, and performing solvent heat treatment at the temperature of 100-120 DEG C to obtain the TiO2 mesoporous monocrystal microsphere and g-C3N4 heterojunction photocatalyst. The TiO2 mesoporous monocrystal microsphere and g-C3N4 heterojunction photocatalyst provided by the invention has good photocatalytic pollutant degradation performance and photocurrent response performance; the preparation method has the advantages that the material is low in price, the process is simple and the structure is controllable; the prepared photocatalyst has very high application prospect and practical value in sewage treatment and air treatment.

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.