Photocatalyst, preparation method thereof, and application of photocatalyst in preparation of hydrogen

Abstract

The invention relates to a photocatalyst, a preparation method thereof, and application of the photocatalyst in preparation of hydrogen, and belongs to the technical field of preparation of hydrogen through photocatalysis. The photocatalyst consists of a carrier SiO2 and a semiconductor component MS, and the constitution form of the photocatalyst is MS(x)@SiO2; the semiconductor component is a metal sulfide, the percentage x of the mass of the semiconductor component in the total mass of the photocatalyst is 1-50%; the semiconductor component is uniformly dispersed on the surface of the carrier or inside holes of the carrier; a metal (s) in the metal sulfide is (are) one or more of cadmium, zinc, copper, indium, silver, nickel and gallium. Through the adoption of the photocatalyst prepared by the preparation method disclosed by the invention, under the condition that only the semiconductor and the inert SiO2 carrier thereof are available, the effect of preparing hydrogen by efficient utilization of sunlight through catalysis can be achieved without the assistance of an auxiliary catalyst like noble metal. The use amount of the semiconductor in the photocatalyst is reduced, so that the cost of the photocatalyst is reduced, and the popularization and application are facilitated.

Description

technical field [0001] The invention belongs to the technical field of hydrogen production by photocatalysis, and specifically relates to a preparation method and its application in hydrogen production without using auxiliary catalysts such as precious metals under the condition that only semiconductors and inert silica carriers exist. Background technique [0002] Hydrogen energy is a high-combustion value, high-efficiency and clean energy source, which is compatible with most current energy systems and can be easily and efficiently converted into electricity and heat. Hydrogen can also be widely used in chemical processes as a bulk chemical, such as the use of hydrogen to achieve CO 2 Transformation, etc., so it has received great attention from the industry and society. [0003] According to statistics, at present, more than 99% of the hydrogen in the world depends on the reformation of fossil resources such as coal, oil, and natural gas (for example: C+2H 2 O→2H 2 +CO...

AI Technical Summary

Problems solved by technology

On the one hand, the components with the strongest distribution in the solar spectrum are mainly concentrated in the visible light region of 400nm to 700nm, so it is of great significance to develop catalysts with visible light absorption; on the other hand, most single semiconductor photocatalysts with photocatalytic activity produce hydrogen by themselves. Both activity and stability are not ideal

Research has found that combining the semiconductor itself with some noble metals or semiconductors with a narrow bandgap (i.e. co-catalyst) can improve hydrogen production activity, such as the composite catalyst supported by platinum on CdS / Ti-MCM-41 in the national invention patent (ZL200610041835.7) In fact, although it can improve the efficiency of hydrogen production, precious metals such as platinum and gold will greatly limit their application in industrial scale-up due to their rarity and high cost; Molybdenum sulfide, tungsten sulfide, etc. with semiconductors can reduce the cost compared with noble metals, but the synthesis steps of such co-catalysts are cumbersome, and generally require relatively harsh conditions such as high-temperature roasting (such as patents ZL201110033996.2, ZL201110144999.3, etc.) , and this kind of co-catalyst is relatively specific, and it will take a long time to explore an effective co-catalyst for a large number of photocatalysts that have been discovered so far.

[0005] In addition, in view of the problems of low efficiency and poor stability of semiconductor catalysts, if we start with the modification of the main semiconductor, we can not only avoid the high cost of noble metals, but also use a more reasonable synthesis process to reduce the loss of catalysts in tedious processes. Realizing the efficient production of hydrogen under visible light is undoubtedly of great significance for promoting hydrogen production by solar photo-splitting of water

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