Layered MoS2 Grown on Anatase TiO2 {001} Promoting Interfacial Electron Transfer to Enhance Photocatalytic Evolution of H2 From H2S

The treatment of hazardous hydrogen sulfide (H 2 S) via photocatalysis technology has been known as one of the most promising green technologies. Photocatalytic production of hydrogen (H 2 ) from H 2 S by two-dimensional (2D) semiconductor materials has gathered great attention owing to its large surface area and high catalytic activity. In this work, layered MoS 2 has been successfully grown on TiO 2 {001} surface to fabricate the 2D MoS 2 /TiO 2 {001} composites for H 2 evolution from H 2 S, which can be confirmed by the X-ray diffraction (XRD) and transmission electron microscopy (TEM) tests. Band structures and UV-Vis spectra provide important evidences that MoS 2 loading can significantly narrow the band gap and broaden the light absorbance into the visible light region. Electron transfer is obviously visualized at the interface of MoS 2 /TiO 2 , resulting in the built-in potential from TiO 2 to MoS 2 , which is determined by the density functional theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) test. Consequently, the photo-induced electrons and holes are accumulated at the sides of TiO 2 and MoS 2 under the illumination, respectively, which largely promote the interfacial electron transfer and prolong the lifetime of photo-generated electrons that participate in the photocatalytic reactions of H 2 evolution from H 2 S. This efficient separation of photo-induced carriers can be further proved by photoluminescence (PL) spectra, photocurrent responses, and electrochemical impedance spectra. As a result, the photocatalytic activity of H 2 evolution is largely increased by 9.4 times compared to the pristine TiO 2 . This study could offer a new and facile way to design highly efficient 2D photocatalysts for the application of H 2 S treatment.