349 results about "Tio2 nanoparticles" patented technology

A photoelectrochemical assay apparatus for determining chemical oxygen demand (COD) of a water sample which consists of a) a measuring cell for holding a sample to be analysed b) a titanium dioxide nanoparticle photoelectric working electrode and a counter electrode disposed in said cell, c) a UV light source adapted to illuminate the photoelectric working electrode d) control means to control the illumination of the working electrode e) potential measuring means to measure the electrical potential at the working and counter electrodes f) analysis means to derive a measure of oxygen demand from the measurements made by the potential measuring means. The method of determining chemical oxygen demand of a water sample, comprises the steps of a) applying a constant potential bias to a photoelectrochemical cell, containing a supporting electrolyte solution; b) illuminating the working electrode with a UV light source and recording the background photocurrent produced at the working electrode from the supporting electrolyte solution; c) adding a water sample, to be analysed, to the photoelectrochemical cell; d) illuminating the working electrode with a UV light source and recording the total photocurrent produced; e) determining the chemical oxygen demand of the water sample according to the type of degradation conditions employed. The determination may be under exhaustive degradation conditions, in which all organics present in the water sample are oxidised or under non-exhaustive degradation conditions, in which the organics present in the water sample are partially oxidised.

A composition and an associated method for chemical mechanical planarization (or other polishing) are described. The composition includes a surface-modified abrasive modified with at least one stabilizer and at least one catalyst differing from the at least one stabilizer. The composition can further include a medium containing the abrasive and an oxidizing agent (e.g., hydrogen peroxide), wherein the at least one catalyst is adapted to catalyze oxidation of a substrate by the oxidizing agent. Preferably, the abrasive is alumina, titania, zirconia, germania, silica, ceria and / or mixtures thereof, the stabilizer is B, W and / or Al, and the catalyst is Cu, Fe, Mn, Ti, W and / or V. Both the stabilizer and the catalyst are immobilized on the abrasive surface. The method includes applying the composition to a substrate to be polished, such as substrates containing W, Cu and / or dielectrics.

The invention discloses a polyurethane foam supported liver / graphene / titanium dioxide nano particle composite material, a preparation method thereof and an application thereof. The material is a three-dimensional structure which is specifically that sliver / graphene / titanium dioxide ternary nano particles are uniformly loaded in the surface and a base body of the polyurethane foam. The preparation method comprises: preparing graphene / titanium dioxide binary nano particles; adding silver nitrate to carry out silver ion modification, thereby preparing silver / graphene / titanium dioxide ternary nano particles; and finally, quickly mixing and stirring a mixed solution of the silver / graphene / titanium dioxide nano particles and diphenyl methylpropane diisocyanate with a mixed solution of polyether polyol and dichloromethane, thereby preparing the polyurethane foam supported liver / graphene / titanium dioxide ternary nano particle composite material. The material provided by the invention has strong adsorption effect, and can degrade oil pollutants on the surface of a water body under irradiation of visible light, thereby achieving great potential in surface water remediation.

The invention belongs to the technical field of treatment and application of nanometer materials and industrial and agricultural wastewater, and provides a magnetic Fe3O4 / SiO2 / TiO2 / quantum dot compounded nanometer photocatalyst and a preparation method and application thereof. The preparation method comprises the following steps of: synthesizing an Fe3O4 magnetic nucleus by a coprecipitation method; preparing an SiO2 protective layer by virtue of hydrolysis reaction and polycondensation reaction of TEOS (Tetraethyl Orthosilicate); then preparing a TiO2 layer on the surface of the SiO2 protective layer by a sol-gel method; and finally modifying Fe3O4 / SiO2 / TiO2 nanoparticles by CdS and CdSe quantum dots. The obtained magnetic Fe3O4 / SiO2 / TiO2 / quantum dot compounded nanometer photocatalyst has very good visible-light photocatalytic capability, can be conveniently and fast recovered and reused by an external magnetic field, and can be used for removing organic pollutants of azo dyes contained in the industrial wastewater.

The invention relates to a graphene / TiO2-based near-infrared / ultraviolet radiation resistant polymer composite film and a preparation method thereof, relating to a near-infrared / ultraviolet radiation resistant composite film and a preparation method thereof. The invention aims to solve the problems of the existing heat reflecting material such as poor heat insulation effect, low transparency, serious light pollution and high production cost and the like. The composite film is prepared by adding the mixed liquid of graphene oxide dispersion and nano-TiO2 dispersion in the curing system of epoxy acrylate at a volume ratio of 1-10:50. The preparation method comprises the following steps: 1) preparing graphene oxide; 2) preparing TiO2 nanoparticles; 3) preparing nanometer graphene / TiO2 composite; and 4) preparing the graphene / TiO2-based near-infrared / ultraviolet radiation resistant polymer composite film. The composite film is mainly used for the glass coating of a building or means of transport for running an air-conditioning system.

The invention belongs to the field of a solar cell, and discloses a perovskite solar cell. The perovskite solar cell sequentially comprises a transparent conductive substrate, an electron transmission layer, an interface modification layer, a modified perovskite active layer, a hole transmission layer and a positive electrode, wherein the electron transmission layer is a nanometer TiO2 particle layer, and the interface modification layer is a fullerene derivative layer. A sol-gel method is employed, high-crystallization TiO2 nanoparticles are synthesized by taking titanium tetrachloride is used as a precursor, the TiO2 nanoparticles are applied to the perovskite solar cell by employing a low-temperature annealing process, a fullerene derivative is directly spin-coated on a surface of the obtained nanometer TiO2 particle layer for modification, the defects in TiO2 and perovskite are passivated, a novel perovskite synthesis path is employed, the obtained perovskite solar cell has high efficiency and does not have hysteresis effect under a low-temperature preparation process, and the device can be used for stable transmission; and moreover, the related preparation method is simple, is low in energy consumption and is suitable for promotion and application.

A multiple elements doped anatase-type TiO2 sol photocatalyst features that its solvent is water or the mixture of water and unitary or binary alcohol, and its sol contains non-metal doped anatase-type TiO2 nanoparticles, and has a formula: TiO2-x-yAxBy, where x=0.0-0.1, y=0.0-0.1 and A or B is one or more of non-metal halogens or N-family elements. Its preparing process includes such steps as hydrolyzing organic or inorganic Ti source, doping, dispergating, and hydrothermal crystallizing.

The invention provides an inorganic nanoparticles-modified polyurethane sponge mask material and a preparation method thereof, and also provides application of the inorganic nanoparticles-modified polyurethane sponge mask material in manufacturing a mask. In the invention, the inorganic nanoparticles used for modifying sponge comprise magnetic Fe3O4 nanoparticles, magnetic Fe2O3 nanoparticles, TiO2 nanoparticles, ZnO nanoparticles, mesoporous SiO2, carbon nanotubes and carbon fibers. The inorganic nanoparticles have the advantages of small particle size, large specific surface area, strong adsorption performance and like and contain charges on the surfaces, and a plurality of the nanoparticles have strong ultraviolet absorption capability, photocatalytic activity, and antibacterial and antiviral actions. The inorganic nanoparticles-modified polyurethane sponge mask material provided by the invention has high efficiency and capability in filtering out sub-micron dust, viruses and bacteria, has the function of adsorbing poisonous and harmful gases, has the characteristics of small gas absorption resistance, simple preparation method, low cost and broad application future, and can be recycled through water washing.

A reverse-osmosis separating membrane with high resitance to scale deposit is prepared through hydrolyzing Ti compound in acidic aqueous solution to generate TiO2 nanoparticles, dispersing them in anaqueous solution (pH=1-6 or 9-13), and dipping the reverse-osmosis separating membrane in it for fixing said TiO2 nanoparticles on it.

The invention discloses a high-dispersion modified graphene lubricating oil and a preparation method thereof. The lubricating oil comprises modified graphene, base oil and a dispersant, wherein the addition amount of the modified graphene is equivalent to 3 to 15wt% of the base oil; and the addition amount of the dispersant is equivalent to 0.5 to 1.0wt% of the base oil. Preferably, the lubricating oil also comprises stearic acid modified TiO2 nanoparticles, and the addition amount of the nanoparticles accounts for 2 to 5 wt% of the base oil. The invention also discloses preparation for the lubricating oil by adopting a microwave manner. The high-dispersion modified graphene lubricating oil provided by the invention has excellent dispersibility and stability among all components, and solves the problem of long-term stability of graphene used as an additive in the base oil.

The invention relates to a photocatalytic composite gel bead and a preparation method as well as an application of the gel bed. The composite bead takes crosslinked alginate as a matrix, and the matrix is filled with titanium dioxide nanometer particles. The preparation method specifically comprises the following steps of: firstly mixing the titanium dioxide, the alginate and water uniformly, dropwise adding the mixed solution into a calcium chloride solution by using an injector to prepare uniform beads, collecting and washing the beads, adding the washed beads into a solution of glutaraldehyde and hydrochloric acid to carry out a crosslinking reaction, and finally collecting and washing the beads to obtain the final product. The product has the advantages of low cost, simple preparation, good light degradation effect, easy separation and recycling and the like, has a good light degradation effect on hexavalent chromium, and can be applied to the treatment of chromium containing wastewater discharged from an electroplating factory, an electronic equipment factory, a metallurgical refinery and the like.

The invention discloses a gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst and application thereof. The gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst having different particle sizes is firstly obtained by preparing a gold nanocluster solution based on chloroauric acid and a reducing type glutathione as raw materials and carrying out an impregnation method and illumination condition control on gold nanocluster solution and titanium dioxide nanoparticles. The gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst is simple in preparation method without high temperature and high pressure conditions; compared with the existing gold nanocluster-titanium dioxide and gold nanoparticle-titanium dioxide catalysts, the gold nanocluster-gold nanoparticle-titanium dioxide compound photocatalyst disclosed by the invention is higher in photocatalytic efficiency and hydrogen production efficiency, can be used for hydrogen production by photolysis of water, and is beneficial to sustainable development of environments and energy sources.

A nano-class deodoring agent for cleaning air is prepared from TiO2 nanoparticles, tourmalinite nanoparticles, muscovite nanoparticles, sodium silicate, sodium benzoate, sodium chloride, polyacrylamide, hydroxyethylene cellulose and propanetriol through ball grinding and baking. Its advantages are high effect to remove benzene, ammonia and formaldehyde by 60-80%, and short time (24hr).

The invention provides a graphene modified composite mesoporous carbon microsphere air purifying preparation. A certain amount of beta-cyclodextrin is added to thin-layered nano-SiO2 particles covering the surfaces of obtained micro-SiO2 particles, a certain quantity of obtained RGO / TiO2 nanoparticles is added simultaneously, -OH, -COOH, C-O-C and C=O oxygen-containing functional groups rich on the surface of graphene are adsorbed by and bonded with the RGO / TiO2 nanoparticles on the basis of the molecular recognition characteristic of beta-cyclodextrin, then a certain amount of CTAB (cetyltrimethylammonium bromide) surfactant is added, CTAB serving as a micelle stabilizer can stop the RGO / TiO2 nanoparticles from further hydrolysis and growth, and finally, the novel air purifying preparation adopting RGO / TiO2 supported by carbon microspheres with a mesoporous shell structure is obtained. With adoption of the scheme, the purity is high, RGO / TiO2 supported by the carbon microspheres with the mesoporous shell structure in powder is better in bonding performance, uniform in distribution and controllable in dimension at mesopores, and the air purifying preparation can be used for purifying polluted air and removing dust in a haze environment as well as photo-catalytically degrading and separating nitric oxide, sulfide or other organic pollutants in the polluted air.

The invention discloses a charged TiO2 / polyelectrolyte composite nanofiltration membrane as well as a preparation method and an application thereof, and belongs to the technical field of membrane separation. The preparation method comprises the following steps: firstly, the surface of a base membrane is charged, so that the base membrane and polyelectrolytes can conveniently generate an electrostatic effect; secondly, the composite nanofiltration membrane is prepared with a method for alternatively depositing anionic and cationic polyelectrolytes and performing electrostatic layer-by-layer self-assembly. Inorganic nanoparticles adopted in the preparation method are modified negatively charged / positively charged TiO2 nanoparticles; as TiO2 has the advantages of good photocatalytic performance, good hydrophilicity and the like, TiO2 is combined with layer-by-layer self-assembly to prepare the TiO2 / polyelectrolyte composite nanofiltration membrane; the preparation method is simple and convenient to operate and is an environment-friendly preparation method; moreover, the prepared TiO2-containing composite nanofiltration membrane has very good hydrophilicity and charge performance, has good pollution resistance, is uniform in structure and can be used for removing divalent metal ions such as Ni<2+> and the like in wastewater as well as dye molecules such as dimethylphenol orange, eriochrome black T and the like at the same time, thereby having a good application effect.

The invention discloses a lithium sulfur battery positive electrode material and a preparation method thereof, wherein the lithium sulfur battery positive electrode material includes a sulfur carbon nano composite material, the sulfur carbon nano composite material includes carbon nanotubes, TiO2 nano particles and nano sulfur powder, the carbon nanotubes are intertwined to form micron grade carbon balls with nano micropore structures which are interconnected, the TiO2 nanoparticles areuniformly dispersed and embedded in the micron grade carbon balls to form composite carbon microspheres, and the nano sulfur powder is evenly filled in the composite carbon microspheres. Sulfur is infiltrated into the composite microspheres which are formed by coating of the TiO2 nanoparticles with the carbon nanotubes, and the lithium sulfur battery positive electrode material is prepared in a water-in-oil microemulsion system. The obtained material is a regular spherical structure with monodispersity and uniformity. After sulfur infiltration, the sulfur is uniformly filled into the microspheres, and the capacity is fully utilized during charging and discharging processes, and the structure can be controlled at the same time.

The invention relates to the technical field of modification of ultrafiltration membranes, and in particular relates to a preparation method for a super-hydrophilic ultrafiltration membrane with photocatalytic performance. According to the method provided by the invention, TiO2 is added into a base membrane through the manner of blending, and a TiO2 functional layer is crosslinked on the surface of the base membrane, so that hydrophilicity of the interior of the ultrafiltration membrane is increased, the overall water flux is improved, and the ultrafiltration membrane has good hydrophilicity,pollution resistance and photocatalytic functions on the surface; and in addition, ultrasonic treatment is adopted, so that TiO2 nanoparticles can be uniformly dispersed in the ultrafiltration membrane, and a stable rejection ratio can be maintained under high-water-flux conditions.

The invention relates to a photoelectrochemical sensor, and preparation and application thereof. A preparation method for the photoelectrochemical sensor comprises the following steps: S1, pretreating ITO electro-conductive glass; S2, adding TiO2 nanoparticles onto the ITO electro-conductive glass drop by drop to prepare an ITO / TiO2 electrode; S3, soaking the electrode in a carbon quantum dot solution for 10 h so as to obtain an ITO / TiO2 / CODs electrode; S4, adding chitosan onto the electrode drop by drop so as to obtain an ITO / TiO2 / CODs / CS electrode; S5, adding a glutaraldehyde solution onto the electrode drop by drop; and S6, dropwise adding thrombin aptamer drops, carrying out a reaction at 4 DEG C under a wet condition for 10 to 15 h, continuing adding bovine serum albumin onto the electrode drop by drop after leaching and blow-drying, and carrying out leaching and blow-drying again. The prepared photoelectrochemical sensor can be used for detection of thrombin. According to the invention, the carbon quantum dots with a wide visible light absorption range, good luminosity and high-efficiency electron injection capability are used as a photosensitizer for titanium dioxide, so the obtained composite structure has good response to photoelectric current under visible light. The prepared photoelectrochemical sensor has the advantages of simple operation, low cost, environment friendliness, high sensitivity and good selectivity.

The invention discloses a preparation method of a polydopamine / titanium dioxide double-layer composite film. The method includes the steps of: 1) adding dopamine hydrochloride into deionized water to obtain a solution A; 2) mixing TiO2 hydrosol with part of the solution A to obtain a solution B; 3) adding a clean substrate into the remaining solution A to perform soaking so as to obtain a polydopamine film on the substrate; and 4) conducting spin-coating of the solution B on the polydopamine film, and performing drying. The preparation method provided by the invention has the characteristics of low cost, simple process, and easy realization, the prepared polydopamine / titanium dioxide double-layer composite film has good biocompatibility, and the TiO2 nanoparticles in the film are dispersed evenly. The polydopamine / titanium dioxide double-layer composite film has strong binding force with the substrate and has certain photo-responsiveness, and can be applied to the fields of biological tissue engineering, photocatalyts and other fields.

The invention relates to the technical field of solid-state polymer electrolyte preparation, and provides a preparation method for a lithium ion battery all-solid-state polymer electrolyte membrane with a three-layer structure through electrostatic spinning. An upper layer and a lower layer adopt PEO with high ionic conductivity as the carrier of lithium salt; a middle layer adopts PVDF with high mechanical strength as the carrier and a transport channel for the lithium salt; meanwhile, the upper layer, the lower layer and the middle layer all adopt TiO2 nanoparticles for modification; and finally layer-by-layer electrostatic spinning is performed by an electrostatic spinning machine for completing the preparation. The preparation method has the beneficial effects that the ionic conductivity and the mechanical strength of the solid-state polymer electrolyte membrane with the three-layer structure prepared by the method are greatly improved compared with the ionic conductivity and the mechanical strength of the corresponding single-layer solid-state polymer electrolyte membrane; and the mechanical strength of the modified solid-state polymer electrolyte membrane with the three-layer structure, added with 3wt% of TiO2 nanoparticles, is improved by 50% compared with the mechanical strength of the corresponding single-layer solid-state polymer electrolyte membrane.

The invention is directed to a method for reducing the chemical activity and photo activity of titanium dioxide nanoparticles comprising adding a densifying agent, such as citric acid, to an aqueous slurry of the titanium dioxide nanoparticles; treating the aqueous slurry with a source of silica, such as a solution of sodium silicate, to form silica treated titanium dioxide nanoparticles; treating the silica treated titanium dioxide nanoparticles with a source of alumina, such as a solution of sodium aluminate, to form silica and alumina treated titanium dioxide nanoparticles. The titanium dioxide nanoparticles described herein are useful in cosmetic, coating and polymer compositions.

The invention discloses a color material under the regulation and the control of an electric field. The color material comprises a medium and a colloidal crystal material uniformly dispersed in the medium, wherein the medium is propylene carbonate or water; the colloidal crystal material is titanium oxide-coated silicon oxide colloidal SiO2 / TiO2 nanoparticles; the volume ratio of the colloidal crystal material to the medium is (1-8): (90-95). The prepared color material is a novel off-color material under the regulation and the control of the electric field, and increases the types of color materials under the regulation and the control of electric fields; the colloidal SiO2 / TiO2 nanoparticles are synthetized by the one-step method, and the method is simple and effective; through regulating the added amount of a titanium source, different coated thicknesses of titanium oxide can be realized; the prepared color material is high in color display brightness, has obvious color changes under the action of a very small electric field, and is high in respond speed.

The invention relates to a preparation method of a TiO2 / ZnFe2O4 / active carbon (AC) composite material. The preparation method comprises the following steps: firstly, synthesizing a ZnFe2O4 / AC composite material by using a hydrothermal method; and further synthesizing the TiO2 / ZnFe2O4 / AC composite material by using a sol-gel method. The composite material has the characteristics of being relatively large in specific surface area, good in magnetic response and photocatalytic property. The composite material prepared by the invention can be applied to adsorbing organic dyes in sewage and has the advantages that firstly, the specific surface area is large and the adsorption capability on organic matters such as dyes in sewage is strong; secondly, ZnFe2O4 nano particles not only can provide good magnetic response for magnetic separation, but also has good visible light responsiveness, so that the photocatalytic property of the composite material is improved; thirdly, TiO2 nanoparticles have the property of photocatalytically degrading organic matters and are regenerated and used under illumination; and fourthly, the composite material can be recycled, so that the sewage treatment cost is lowered and the resources are saved.

The invention discloses modified graphene lubricating oil with good dispersibility and affinity and a preparation method thereof, the modified graphene lubricating oil comprises modified graphene, base oil, an affinity agent and a dispersing agent, the adding amount of the modified graphene accounts to 3-15wt% of the base oil, the adding amount of the affinity agent accounts to 0.1-2wt% of the base oil, the adding amount of the dispersing agent accounts to 0.5-1.0wt% of the base oil, preferably, the lubricating oil also includes stearic-acid-modified TiO2 nanoparticles, and the adding amount of the nanoparticles accounts to 2 to 5wt% of the base oil. The invention also discloses a method for preparing the lubricating oil by microwave. The high dispersion modified graphene lubricating oil has excellent dispersion and stability, and solves the problem of long-term stability of the graphene as an additive in the base oil.

The invention discloses an antibacterial type nanofiber composite material and a preparation method thereof. A hybrid-structured PLA-TiO2 fiber film with nano pores formed in whole fiber bodies and nano protrusions arranged on the fiber surface is adopted as the antibacterial type nanofiber composite material; the antibacterial ratio of the composite material on staphylococcus aureus is 99% or above, the antibacterial ratio of the composite material on escherichia coli is 95% or above, the filtering efficiency of the composite material on sodium chloride aerosol particle air with the weight median diameter of 260 nm reaches up to 99.98% or above, and the filtering resistance is smaller than 150 Pa. The preparation method comprises the steps that TiO2 nanoparticles are added into a PLA solution, electrostatic spinning is performed, and the hybrid-structured PLA-TiO2 fibers with the nano pores formed in the whole fiber bodies and the nano protrusions evenly distributed on the fiber surface are prepared through a one-step method. The preparation method is simple and low in cost, and the prepared composite material not only has the higher antibacterial property, but also has the high filtering efficiency and the low filtering resistance and is a functional filtering and protecting material with the potential application prospect.

The invention relates to a preparation method of a functional cellulose aerogel. The method comprises the following steps: generating an acyl hydrazone bond and introducing chemical crosslinking intoaerogel to prepare the functional cellulose aerogel composite material with high mechanical properties. The chemical crosslinking is introduced on the basis of traditional cellulose aerogel, so that the crosslinking degree between cellulose nano-fibers is increased; the compression performance of the cellulose aerogel and the shape keeping performance in a water environment are enhanced and the cracking caused by the fact that a hydrogen bond is damaged in a water environment is reduced; the mechanical properties of the aerogel are improved and the actual applicability of the aerogel is widened; the TiO2 nanoparticles with photocatalytic activity are doped through a suitable method to prepare the functional cellulose composite aerogel with wider applicability, and adsorption and degradation of organic dyestuffs in the atmosphere and a water body are realized.

The present invention is directed to black TiO2 nanoparticles having H2-plasma induced surface defects. The surface defects generate mid-band gap states, which enable the black TiO2 nanoparticles to absorb visible and IR light. The enhanced visible and IR light absorption allows the black TiO2 nanoparticles to serve as photocatalysts in the solar-induced decomposition of pollutant organic compounds in water, an important application in water treatment systems. The present invention is further directed to a method of generating the black TiO2 nanoparticles utilizing H2-plasma to introduce surface defects without changing the oxidation state of the titanium in the nanomaterial.

The invention discloses a composite wave-absorbing material based on MXene and metal organic framework. The composite wave-absorbing material is characterized in that the composite wave-absorbing material is a composite material which is obtained by loading metal nanoparticles and TiO2 nanoparticles on a layered carbon framework obtained by compounding a layered nanosheet MXene matrix Ti3C2 and athree-dimensional metal organic framework MOFs material. The invention also discloses a preparation method of the composite wave-absorbing material and an application of the composite wave-absorbing material in an electromagnetic wave absorbing material. According to the composite wave-absorbing material based on the MXene and the metal organic framework and the preparation method of the compositewave-absorbing material, the composite wave-absorbing material obtained through an in-situ chemical synthesis method and a heat treatment process has controllable, excellent and stable microwave absorption performance; and when the thickness of a sample is 3.0 mm, the maximum absorption strength can reach -51.8 dB.

A method of manufacturing a neutral and transparent metal oxide colloid solution containing dispersed titanium dioxide nano particles comprising the steps of (i) adding a titanium compound and a stabilizer to alcohol to produce a titanium-containing solution and (ii) neutralizing the titanium-containing solution of step (i) by adding a basic solution to produce a neutralized solution with the pH of the neutralized solution in a range of 6-8; and (iii) heating the neutralized solution at a temperature of above 75° C.

The invention belongs to the technical field of materials, in particular to a preparation method of a composite photocatalyst TiO2 / g-C3N4 derived from MOF (Metal Organic Frameworks). The photocatalystis prepared by a hydrothermal method and a calcination method. A porous titanium-based metal organic framework MIL-125 is prepared by the hydrothermal method. Porous TiO2 nanoparticles are obtained by the calcination process. Melamine is grown in situ on the porous titanium-based metal organic framework MIL-125 by calcination process to obtain the composite photocatalyst TiO2 / g-C3N4. The preparation method provided by the invention is simple, and problems such as agglomeration of TiO2 particles, low specific surface area and low utilization rate of visible light can be effectively solved. Thespecific surface area of the TiO2 can be improved by the porous structure of the titanium-based metal organic framework MIL-125. A photocatalytic range of the TiO2 can be effectively improved by theg-C3N4. The composite photocatalyst TiO2 / g-C3N4 can effectively broaden a spatial distance of photogenerated electron holes, and inhibit the combination of the two. Therefore, the photocatalytic efficiency is greatly improved, the cost is low, environmentally frendly is ensured, and the practical applications and the industrialized productions are improved.