14.MoS2 quantum dots@TiO2 nanotube composites with enhanced photoexcited charge separation and high-efficiency visible-light driven photocatalysis

作者：Fenfen Zhao ¹, Yuefei Rong ¹, Junmin Wan ^{1, 2}, Zhiwen Hu ¹, Zhiqin Peng ¹ and Bing Wang ¹

来源：Fenfen Zhao et al 2018 Nanotechnology 29 105403

DOI：10.1088/1361-6528/aaa68c

摘要：MoS₂ quantum dots (QDs) that are 5nm in size were deposited on the surface of ultrathin TiO₂ nanotubes (TNTs) with 5nm wall thickness by using an improved hydrothermal method to form a MoS₂ QDs @ TNT visible-light photocatalyst. The ultrathin TNTs with high percentage of photocatalytic reactive facets were fabricated by the commercially available TiO₂ nanoparticles (P25) through an improved hydrothermal method, and the MoS₂ QDs were acquired by using a surfactant-assisted technique. The novel MoS₂ QDs @ TNT photocatalysts showed excellent photocatalytic activity with a decolorization rate of 92% or approximately 3.5 times more than that of pure TNTs for the high initial concentration of methylene blue solution (20 mg l⁻¹) within 40min under visible-light irradiation. MoS₂ as the co-catalysts favored the broadening of TNTs into the visible-light absorption scope. The quantum confinement and edge effects of the MoS₂ QDs and the heterojunction formed between the MoS₂ QDs and TNTs efficiently extended the lifetime of photoinduced charges, impeded the recombination of photoexcited electron–hole pairs, and improved the visible-light-driven high-efficiency photocatalysis.

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