Preparation method and application of a CD/CDS heterojunction visible photocatalyst rich in sulfur vacancies

Abstract

The invention discloses a preparation method and application of a Cd / CdS heterojunction visible light catalyst rich in sulfur vacancies. Using CdS prepared by solvothermal method as the precursor, the intermediate CdO / CdS composite material was synthesized by heat treatment method and directly obtained by in-situ chemical reduction method of sodium borohydride. The Cd / CdS composite visible light catalyst prepared by the present invention contains a large number of sulfur vacancies, which greatly improves the absorption and utilization of visible light by the catalyst, and the highly conductive Cd and CdS have closer contact, thereby photogenerating electron-vacancies. The holes can be separated better and the photocatalytic efficiency is higher. The heterojunction photocatalyst has high stability, exhibits excellent photocatalytic activity under visible light irradiation, and can be used to catalyze the photolysis of water to produce hydrogen. The invention requires low preparation conditions, is simple to operate, and has cheap and easily available raw materials. It is environmentally friendly and has high visible light catalytic efficiency. It has broad application prospects in the field of photocatalysis.

Description

technical field [0001] The invention belongs to the technical field of material preparation and visible light photocatalysis, and in particular relates to a preparation method and application of a Cd / CdS heterojunction visible light catalyst rich in sulfur vacancies. Background technique [0002] With the rapid development of the economy, the problems of environmental pollution and energy shortage have become increasingly prominent, becoming two major challenges facing the development of human society in the 21st century. Semiconductor photocatalysis technology is based on the conversion and storage of solar energy, and uses light energy to drive photocatalytic reactions. Converting solar energy into chemical energy is considered to be an ideal way to solve the two problems of energy and environment. However, the application of photocatalyst technology in actual production still faces some problems. For example, low quantum efficiency, narrow photoresponse range of photoca...

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Problems solved by technology

However, limited by its preparation method, this patented technology cannot flexibly control the morphology of the CdS matrix and generate abundant sulfur vacancies, so it cannot take advantage of the advantages of morphology control and defect engineering, and it is difficult to efficiently optimize the light absorption and light absorption of CdS. Catalytic properties

Zhang Tierui Group (L. Shang, B. Tong, H.Yu, G.I.N. Waterhouse, C. Zhou, Y. Zhao, M. Tahir, L.-Z. Wu, C.-H. Tung, T.Zhang, Advanced Energy Materials 6 (2016) 1501241) reported a Cd nanosheet-modified CdS nanoparticle and applied it to photocatalytic hydrogen production. The report pointed out that they first prepared Cd nanosheets by chemical reduction, and then sulfurized them to obtain Cd The composite catalyst of nanosheets and CdS, which has a high performance of photolysis of water to produce hydrogen, but also faces the constraints of the above problems, cannot give full play to the advantages of morphology control and defect engineering, which severely limits the application research of CdS photocatalysts

The preparation method and material morphology mentioned in the above patent and the paper are fundamentally different from this patent, and more importantly, there is a lack of abundant S vacancy defects that play a key role.

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