Study on photocatalytic activity of MoS 2 /ZnO composite in visible light
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Vol.16 No.6, 1 November 2020
Study on photocatalytic activity of MoS2/ZnO composite in visible light* TANG Chun-mei (ୀ᱕ẵ), ZHANG Hong-yan (ᕐ㓒⠅)**, and ZHANG Jun (ᕐߋ) School of Physical Science and Technology, Xinjiang University, Urumqi 830046, China1 (Received 31 December 2019; Revised 16 April 2020) ©Tianjin University of Technology and Springer-Verlag GmbH Germany, part of Springer Nature 2020 A series of MoS2/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and UV-vis absorption were used to characterize the prepared MoS2/ZnO photocatalysts. It was proved that the combination of MoS2 and ZnO can increase the content of oxygen vacancies on surface of ZnO, thus improving the light absorption capacity in visible light region and reducing the band gap of ZnO. And the photocatalytic performance of ZnO was improved. Experimental results show that the MoS2/ZnO (3 wt%) compound has the highest degradation rate for methylene blue (MB) under visible light, which means that it has the best photocatalytic activity among all the prepared samples. Document code: A Article ID: 1673-1905(2020)06-0446-5 DOI https://doi.org/10.1007/s11801-020-9227-6
In recent years, environmental pollution is increasing and a large number of organic and toxic pollutants enter into the waste water flow with rapid development of industry[1]. There are many different chemical and physical methods for degrading these pollutants in water, which semiconductor photocatalytic technology is considered to be a promising and environment-friendly method due to the special physicochemical properties of semiconductors[2]. Semiconductor metal oxides/sulfides/nitrides are of great interests to researchers because of their unique photocatalytic properties[3]. Metal oxide semiconductors (such as ZnO, TiO2, CeO2 and WO3) are widely studied for photocatalytic applications due to their high stability, low cost and ecological properties[4-6]. As a metal oxide semiconductor, zinc oxide (ZnO) is considered as an important N-type semiconductor photocatalyst due to its high photocatalytic activity, low production cost, non-toxicity and environmental friendliness[7]. However, ZnO has a large exciton binding energy (60 meV) and a wide band gap (~3.3 eV), which results in a narrow spectral response range (only excited by UV spectrum) and low separation efficiency of photogenerated carriers, which limits the photocatalytic activity of ZnO under natural light[8]. It is well known that the combination of ZnO and other materials (such as narrow band gap semiconductors, precious metals, carbon materials) can improve the photocatalytic activity of ZnO under visible light and inhibit the recombination rate of photo-generated electrons and holes, thereby fundamentally improve the application of ZnO as a photocatalyst[9]. Among narrow band gap semiconductors, molybdenum disulfide (MoS2) is a photocatalyst with a unique * *
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