49results about How to "Enhance photocatalytic hydrogen production activity" patented technology

The invention discloses a carbon dot/carbon nitride/titanium dioxide composite material which is formed by compounding of three-phase carbon dots, graphene-like carbon nitride and titanium dioxide, wherein carbon nitride has a large surface area so as to just provide a depositing space for titanium dioxide nanosheets, so that titanium dioxide cannot cluster; and meanwhile, carbon nitride has relatively narrow energy gap and can increase the light response range. Furthermore, compounding of photo-induced electrons can be further inhibited by utilizing the unique electron transfer capacity of carbon dots, so as to increase the photocatalytic capacity. Moreover, the preparation method is mild in process conditions and low in cost, and the composite material is suitable for large-scale production, and has wide application prospect.

The invention discloses a photocatalyst based on graphite phase carbon nitride g-C3N4, and a preparation method and an application thereof. The photocatalyst based on graphite phase carbon nitride g-C3N4 has a high photocatalytic hydrogen production activity, the hydrogen production activity is higher than 600 [mu]mol.g<-1>.h<-1>, and the photocatalytic hydrogen production activity of bulk phase graphite phase carbon nitride g-C3N4 is significantly improved. The preparation method of the photocatalyst based on the graphite phase carbon nitride g-C3N4 comprises the following steps: preparing g-C3N4 nano-sheets from the bulk phase g-C3N4 by physical or chemical treatment, and calcining the g-C3N4 nano-sheets at a high temperature to prepare the photocatalyst based on graphite phase carbon nitride g-C3N4, with different photocatalytic activities. The preparation method has the advantages of simplicity, short operation cycle, low cost, and suitableness for large-scale industrial production. The photocatalyst based on graphite phase carbon nitride g-C3N4 can be used in the fields of photocatalytic water decomposition for hydrogen production, photocatalytic carbon dioxide reduction, fueldegradation, pollutant degradation and the like.

The invention discloses a preparation method and an application of a highly crystallized carbon nitride photocatalytic material, and belongs to the technical field of semiconductor photocatalytic materials. The method comprises the following steps: 1) calcining melamine in a muffle furnace to obtain a heptazine precursor; 2) grinding and uniformly mixing the heptazine precursor, potassium salt andlithium salt, and calcining the mixture in the muffle furnace; 3) taking out the calcined product, and cleaning and drying the calcined product to obtain crystallized carbon nitride; and 4) dispersing the obtained crystallized carbon nitride in hydrochloric acid, continuously stirring the system, and finally washing and drying the system to obtain the highly crystallized carbon nitride photocatalytic material. In the invention, the crystallized carbon nitride is treated in the hydrochloric acid aqueous solution, so that the crystallinity of the obtained carbon nitride is greatly enhanced. Thehigh-crystallinity carbon nitride has great advantages in the aspects of photo-generated carrier migration and photo-generated electron hole pair inhibition. Meanwhile, potassium ions embedded into the high-crystallization carbon nitride middle layer make great contribution to migration of photo-induced electrons. Based on the two characteristics, the photocatalytic hydrogen production activity of the high-crystalline carbon nitride is greatly enhanced.

The invention aims at providing a composite semiconductor photocatalyst and an application thereof and relates to the field of photocatalytic materials. The photocatalyst is prepared by adopting the following method which comprises the following steps: preparing a precursor solution; mixing the precursor solution, a dispersing agent and a solvent, stirring and reacting for 0.5-5h at the temperature of 20-50 DEG C, and removing the solvent to obtain gel; firstly, treating the gel under the protection of nitrogen, then grinding, carrying out acid washing and water washing, and drying to obtain the composite semiconductor photocatalyst. The invention also provides the application of the composite semiconductor photocatalyst in the aspect of degrading organic pollutants and making hydrogen by water decomposition. The composite semiconductor photocatalyst has the advantages that the transferring distance between CdS and TiO2 is shortened, the photocorrosion rate of the surface of the CdS is reduced, not only can the dispersing effect of the CdS on the surface of the TiO2 be improved, but also the service life of the CdS is prolonged, and simultaneously the photocatalytic activity of the CdS is improved.

The invention discloses a visible light driven photocatalysis hydrogen production catalyst as well as a preparation method and application thereof. According to the technical scheme of the invention, tetraisopropyl titanate and tantalum-containing polyacid Ta-POMs-1 are adopted as precursors, the photocatalysis hydrogen production catalyst Ta-POM-1/TiO2 is prepared by using a sol-gel method; and by optimizing and selecting types and amounts of dye molecules, types and amounts of sacrifice catalysts and amounts of the catalyst, the reaction conditions of catalysis hydrogen production with visible light, of the catalyst, can be optimized. Compared with parent TiO2 and POMs, a prepared Ta-POM-1/TiO2 composite photocatalysis material is relatively good in visible light absorption and relatively high in photocatalysis hydrogen production activity, so that the visible light driven photocatalysis hydrogen production catalyst is relatively good in application prospect in the field of photocatalysis.

The invention discloses a heterojunction photocatalyst for hydrogen production and alcohol oxidation by high-efficiency photocatalytic water-cracking, and belongs to the field of photocatalyst preparation and application. According to the invention, nickel sulfate hexahydrate, sodium selenite and titanium dioxide are taken as reactants, glycol is taken as a solvent and a reducing agent, and then aNiSe/TiO2 heterojunction photocatalyst is synthesized according to a one-step solvothermal method. The heterojunction photocatalyst prepared by the invention has a photocatalytic hydrogen productionperformance 9 times higher than that of pure TiO2, and shows good stability in the long-cycle operation. Furthermore, simple alcohols are taken as sacrificial agents, and chemicals of high-value fuel(hydrogen), small molecular acids, aldehydes and the like are prepared through the photocatalytic water cracking under illumination of simulated sunlight. In addition, the heterojunction photocatalystused in the invention is green and simple in preparation method, rich in material sources, low in cost and stable in activity, and combines the small molecular alcohols as the sacrificial agents, sothat economic benefits of photocatalysis and the utilization rate of absorbed light energy can be greatly improved.

The invention discloses a preparation method of a 2D/2D g-C3N4/ZnIn2S4 heterojunction composite photocatalyst. The preparation method includes: firstly modifying a ZnIn2S4 photocatalyst with sodium citrate to find an optimal dosage; then further optimizing the g-C3N4 photocatalyst; and performing in-situ growth of a layer of ZnIn2S4 nanosheet on the surface of a g-C3N4 nanosheet, thus obtaining the 2D/2D g-C3N4/ZnIn2S4 heterojunction composite photocatalyst. The preparation method provided by the invention is simple, the raw materials are easily available, and reaction conditions are moderate.The prepared g-C3N4/ZnIn2S4 two-dimensional composite photocatalytic material has efficient photocatalytic hydrogen production activity, and the hydrogen production rate reaches 3.4mmol/h/g, which isincreased by 180% compared with the hydrogen production rate of single g-C3N4.

The invention relates to the technical field of composite photocatalysis, in particular to a NiCoP-g-C3N4/CdS composite photocatalyst as well as a preparation method and application thereof. The method comprises the steps of firstly, preparing pure CdS through a solvothermal method, and preparing g-C3N4 by directly calcining urea, wherein the g-C3N4 and the CdS have proper valence band and conduction band structures; preparing a g-C3N4/CdS heterojunction through a chemical adsorption and self-assembly method; then adding a nickel source, a cobalt source and a phosphorus source into ultrapure water according to the mass ratio of 1: 1: 5; after the mixture is fully stirred and dissolved, adding a prepared g-C3N4/CdS composite material, carrying out uniform ultrasonic treatment, completely evaporating moisture to dryness, and finally, calcining to successfully load granular NiCoP on the surface of the g-C3N4/CdS heterojunction. The color of the composite material is related to the doping amount of NiCoP, the color of the composite material is gradually darkened from grass green along with the increase of the doping amount of NiCoP, the prepared composite photocatalyst is applied to a hydrogen evolution experiment, the hydrogen evolution performance is excellent, the hydrogen evolution rate is more than 23 times that of pure CdS, the repeated utilization rate is high, and the composite photocatalyst has a wide application prospect in the field of photocatalysis.

The invention discloses a Nb-Rh co-doped titanium dioxide nanorod photocatalyst, and a preparation method and application thereof. The photocatalyst of the invention has the following advantages: 1) the photocatalyst prepared in the invention has a one-dimensional rod structure and is effectively improved in photocatalytic hydrogen production activity compared with a common photocatalyst; 2) the preparation method of the photocatalyst is simple and can easily realize large-scale commercial production; 3) the photocatalyst can be reused, and the catalytic activity of the Nb-Rh co-doped titaniumdioxide nanorod photocatalyst is free of obvious decline after reuse 20 times or more; and 4) the Nb-Rh co-doped TiO2 nanorod photocatalyst has high catalytic activity, e.g., a Ti<0.996>Nb<0.002>Rh<0.002>O<2> nanorod photocatalyst has a hydrogen production rate of up to 7.58 mmol/g.h in photolysis of water, which is 194 times the hydrogen production rate (0.039 mmol/g.h) of TiO2 nanorods preparedunder the same conditions.

The invention discloses a preparation method of Zn-Cr-O/TiO2-nanotube (NTs) composite oxide with efficient photoelectric conversion and photocatalytic performance. The specific preparation method comprises the steps that through an electrochemical workstation, the oxide voltage and time are controlled, in an electrolyte prepared through lower alcohol, fluoride and ultrapure water, through the anodic oxidation method, the precursor is prepared, program warming and roasting are carried out, and TiO2-NTs is obtained; the TiO2-NTs is immersed in a zinc nitrate and chromic nitrate mixed solution with the quantity relative ratio being (1.0 to 7.0):1.0, the cathode deposition and electrochemical oxidation technology is adopted into TiO2-NTs loaded Zn-Cr-O composite oxide, deposition sample rotating is carried out, and the Zn-Cr-O/TiO2-NTs composite oxide with excellent photoelectric conversion and photocatalytic performance is obtained.

The invention relates to a Nb-Rh co-doped titanium dioxide photocatalyst, and a preparation method and application thereof. The catalyst is synthesized by doping modification of TiO2 with Nb and Rh. The Ti<1-x-y>Nb<x>Rh<y>O<2> photocatalyst synthesized through doping modification has excellent photocatalytic effect and is mainly applied to photocatalytic cracking of water and photocatalytic cracking of organic matters. The modified Ti<1-x-y>Nb<x>Rh<y>O<2> photocatalyst maintains the original chemical stability of TiO2. With the above characteristics, the photocatalyst has good application prospects in the fields of energy and environment.

The invention discloses a preparation method and an application of a cadmium sulfide nanosheet and belongs to the technical field of preparation of semiconductor photocatalytic materials. The preparation method includes (1), placing cadmium salt in a small crucible, covering the small crucible with a lid, and placing the small crucible in a big crucible; (2), adding thiourea in the big crucible until the small crucible is coated with thiourea; (3), covering a lid of the big crucible, calcining the big crucible in a muffle furnace at the temperature of 300 DEG C, and holding the temperature for4 hours, naturally cooling to the room temperature after finishing the reaction, and then taking out a product; (4), grinding, cleaning and drying the product to obtain the cadmium sulfide nanosheet.As a solid precursor- cadmium salt is calcined in the atmosphere of thiourea to prepare the cadmium sulfide nanosheet, adding of any organic or inorganic solution is avoided in the preparation process; preparation conditions are mild, operation is convenient, and accordingly the preparation method is suitable for large-scale industrial production; further, the photocatalytic hydrogenation activity of the cadmium sulfide nanosheet is improved greatly.

The invention discloses a preparation method of strontium titanate with adjustable strontium vacancy and an application of strontium titanate in photocatalytic hydrogen production. Strontium titanatecrystals are prepared by a citric acid complexing method, a strontium titanate sample is obtained by calcining, strontium titanate with different strontium vacancy content is obtained by changing theuse amount of strontium acetate in the photocatalytic material provided by the invention, strontium vacancies are introduced into strontium titanate, so that the separation efficiency of photo-inducedelectrons and holes excited by the strontium titanate photocatalyst under an illumination condition is improved, the photocatalytic hydrogen production efficiency of the catalyst is improved, and thehydrogen production efficiency can be well improved when strontium titanate containing a proper amount of strontium vacancies is used for photocatalytic hydrogen production, the maximum average hydrogen production efficiency after illumination can reach 5.8202mmol/g, therefore thestrontium titanate catalyst has a potential application value for solving the problem of energy crisis and alleviatingthe lack of existing resources.

The invention relates to a ZnIn2S4 photocatalyst synergistically modified by a hole assistant Ti(IV) and an electron assistant MXene QDs, belongs to the technical field of photocatalysis, and particularly discloses a ZIS/Ti/MQDs composite photocatalyst, a preparation method and application thereof. The ZIS/Ti/MQDs composite photocatalyst comprises, by mass, 1%-4% of MXene quantum dots; and 96%-99% of a ZIS/Ti mixture; the ZIS/Ti mixture is ZnIn2S4 doped with Ti(IV), and the doping mass percent of the Ti(IV) is 0.2%. According to the invention, ZnIn2S4 is synergistically modified by utilizing the hole assistant Ti(IV) and the electron assistant MXene QDs, and abundant active sites are provided for hydrogen evolution reaction. The preparation method provided by the invention is simple in process, and the prepared composite photocatalyst has very high efficiency of catalytically cracking water to produce hydrogen when no noble metal is used as a cocatalyst, is high in photocatalytic activity, low in cost and pollution-free, can be recycled, and is high in application and popularization performance.

The invention discloses a dibenzo fused dinaphthyl polymer photocatalyst for hydrogen production by photocatalytic decomposition of water and a preparation method thereof, the photocatalyst is prepared by a simple binary or ternary copolymerized Suzuki coupling reaction, and the construction unit of the photocatalyst comprises dibenzo fused dinaphthyl and dibenzothiophene sulfone. The dibenzo fused dinaphthyl monomer and the dibenzothiophene sulfuryl monomer for polymerization have the same or different polymerizable functional groups, and can be subjected to Suzuki coupling reaction. The polymer photocatalyst has the characteristics of high photocatalytic hydrogen production activity, high apparent quantum efficiency and continuous and adjustable structure and composition, is simple in preparation process, high in yield and stable in performance, can release hydrogen under sunlight, and can be used in the field of photocatalytic hydrogen production.