31results about How to "Improve photocatalytic hydrogen production efficiency" patented technology

The invention discloses a preparation method of an anatase type TiO2 crystal face heterojunction. The method includes: adopting hydrothermal reaction, using tetra-n-butyl titanate as the titanium source, taking anhydrous ethanol and deionized water as the solvent, employing ammonia water as the mineralizer, and utilizing {001} crystal face exposed anatase type TiO2 nanosheet as the composite substrate, performing intense agitation at room temperature, and then conducting hydrothermal treatment at high temperature, thus obtaining the anatase type TiO2 crystal face heterojunction. The inventionadopts a twice hydrothermal process to synthesize the anatase type TiO2 crystal face heterojunction for the first time. The preparation method provided by the invention has the characteristics of simple process, easily available conditions, no pollution and low cost, and is conducive to controllable preparation. The obtained composite material forms a high-quality heterojunction interface and shows good photocatalytic performance, and has wide potential application prospects in photodegradation, photolysis of water, photocatalytic reduction of CO2, and other environmental protection and energyfields.

The invention discloses a preparation method for depositing silver on the surfaces of titanium dioxide nanoflowers. A silver nanoparticle / titanium dioxide nanoflower composite material prepared by themethod is formed by compounding titanium dioxide nanoflowers and silver nanoparticles, wherein the titanium dioxide nanoflowers provide a large specific surface area and are rich in a large number ofoxygen vacancies, silver nanoparticles are uniformly reduced and deposited on the surface of titanium dioxide, and close interfacial contact is formed between the silver nanoparticles and the titanium dioxide. The silver nanoparticle / titanium dioxide nanoflower composite material disclosed by the invention is a high-efficiency and stable photoelectric conversion material, a one-step simple reduction method is adopted, the preparation process is simple, reaction conditions are easy to control, and the method is suitable for large-scale preparation and industrialized production.

The invention discloses a preparation method and application of a visible light response hydrogen generation photocatalyst GO / SiC / WO3. The preparation method comprises the following steps: a, siliconcarbide (SiC) is pretreated; b, tungsten trioxide (WO3) is taken as a raw material to prepare a 8wt% WO3 solution of a whole hydrothermal reaction system; c, 100 mL of the 8wt% WO3 solution is taken and placed in a beaker, and the SiC, graphene oxide (GO) and two drops of 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid are sequentially added, and ultrasonically stirred to be evenly mixed; and d, the mixture is transferred into a high-temperature reaction kettle to react for 20 h at 200 DEG C, then centrifugal washing is conducted till the pH is 7, the mixture is placed in a vacuumdrying box to be subjected to vacuum drying for standby application, and the visible light response hydrogen generation photocatalyst GO / SiC / WO3 is obtained through hydrothermal synthesis. Through the synergistic effect of the double cocatalysts, namely the graphene-like material GO and the non-graphene-like material WO3, and the amphipathicity of the ionic liquid, the visible light response hydrogen generation photocatalyst GO / SiC / WO3 is prepared, the performance of visible light photocatalytic water decomposition for hydrogen generation is improved, and a certain foundation can be laid forsubsequent efficient application of the visible light catalyst.

The invention discloses a quantum dot catalyst doped with metal ions. The catalyst includes a light-harvesting unit and a catalyzing unit, wherein the light-harvesting unit includes one, two or several kinds of quantum dots, and the catalyzing unit comprises the metal ions doped in the quantum dots. The metal ions are dispersed on the quantum dots in the following one or several manners that: (1) the metal ions are adhered to the surface of the quantum dots; (2) the metal ions are uniformly dispersed in the quantum dots; (3) the metal ions are disposed in the quantum dots in a gradient alloy way; (4) the metal ions are merely disposed on cores of core-shell quantum dots; (5) the metal ions are merely disposed on shells of the core-shell quantum dots; (6) both the cores and shells of the core-shell quantum dots are doped with the metal ions. The invention further discloses a photocatalytic hydrogen production system of doped quantum dots. The system has high efficiency of a quantum-dot-catalyst photocatalytic hydrogen production system and simplicity of a single quantum-dot photocatalytic hydrogen production system. The system can conveniently combine with an oxygen production half-reaction to totally decompose water.

The invention relates to a material CdS / Ba0.4Sr0.6TiO3 for producing hydrogen by photocatalytically decomposing water, which is a heterostructure catalyst formed by supporting CdS onto Ba0.4Sr0.6TiO3. The catalyst is prepared by a one-step hydrothermal process. When the mole ratio of the CdS to the Ba0.4Sr0.6TiO3 is 0.4:1, the expression is 40%CdS / Ba0.4Sr0.6TiO3, and the material has the optimal catalytic effect. Under simulated sunlight, by using Na2S / Na2SO3 as a sacrifice reagent, the hydrogen production efficiency by photocatalytically decomposing water of the 40%CdS / Ba0.4Sr0.6TiO3 is up to 1268.4 mu mol.h<-1>.g<-1> under the condition of no noble metal for cocatalysis. The one-step hydrothermal process is directly used for synthesizing the catalyst, is simple to operate, has the advantages of low production cost, higher synthesis yield, higher purity and favorable repetitiveness, and is suitable for the requirement for scale-up production; the catalyst has high stability and is convenient for reutilization; and the catalyst has very high photocatalytic hydrogen production ratio under simulated sunlight.

The invention relates to a graphite-phase carbon nitride foam photocatalyst material and a preparation method thereof. Its technical scheme is: add 5-14 mass parts of graphite phase carbon nitride into 100 mass parts of deionized water, mix, then add 1.7-2.0 mass parts of sodium dodecylsulfonate, 1.7-2.0 mass parts Dodecyl alcohol and 1.7 to 2.0 parts by mass of resin glue are stirred at 40 to 60°C and 100 to 200r / min for 10 to 20 minutes to obtain a mixed solution; then the mixed solution is stirred at 1500 to 2000r / min 15 to 20 minutes, then add 5 to 14 parts by mass of binder, and continue to stir for 5 to 10 minutes to obtain a graphite-phase carbon nitride foam slurry; cast the graphite-phase carbon nitride foam slurry and freeze-dry for 6 to 12 hours , drying at 80-100° C. for 18-24 hours to obtain a graphite-phase carbon nitride foam photocatalyst material. The invention has simple process and low cost; the photocatalytic hydrogen production efficiency of the prepared graphite-phase carbon nitride foam photocatalytic material is high.

The invention provides a method for preparing a zinc oxide / zinc sulfide nano heterojunction photocatalyst. The catalyst is a heterojunction catalyst formed by loading ZnO to ZnS, and is formed through a two-step calcination method employing MOF-5 as a template, and an expression of the catalyst is ZnOS-x when ZnS-C is calcined in air for x minutes. The method has the advantages that (1) a heterojunction is firstly prepared by adopting a metal-organic frame complex as the template, and the catalyst prepared by the method compared with the prior art can reach a nanoscale and can be synthesized on a large scale; (2) the prepared catalyst is high in photocatalytic hydrogen production efficiency in visible light under the condition of not needing any co-catalyst; and (3) the prepared catalyst is good in stability and repeated utilization is facilitated.

The invention relates to a titanium dioxide-platinum-tricobalt tetraoxide tri-element composite photocatalytic material and a preparation method thereof.Titanium dioxide nanosheets with exposed faces {001} and {101} are used as a carrier, platinum and tricobalt tetraoxide nanoparticles are used as a co-catalyst, the platinum particles are loaded on the faces {101} of the titanium dioxide nanosheets, and the tricobalt tetraoxide nanoparticles are loaded on the faces {001} of the titanium dioxide nanosheets.Photocatalytic decomposing water of the material is high in hydrogen generating efficiency, and the co-catalyst and titanium dioxide are combined closely, so that the material is high in stability after long-time use and the problem that photocatalytic efficiency is lowered caused by the fact that photocatalyst electron holes are highly prone to compositing in the prior art is solved effectively.