Hydrothermal synthesis of MoS2-decorated silicon nanowires heterostructure with enhanced performance of photocatalytic activity under visible light.

[Display omitted] • MoS 2 nanosheets were successfully deposited onto silicon nanowires (SiNWs) through hydrothermal process. • The MoS 2 /SiNWs heterostructure have been successfully prepared by combing hydrothermal and metal assisted chemical etching processes. • MoS 2 /SiNWs heterostructure exhibited an improvement of photocatalytic degradation of MB under visible light irradiation. Molybdenum disulfide (MoS 2) is weakly stacked by vander Waals force, and the interaction force between the layers of MoS 2 and Silicon is weak. Therefore, direct growth of homogeneous high quality MoS 2 films on silicon substrates stays challenging. Herein, for the first time, few layered MoS 2 nanosheetswere successfully deposited onto silicon nanowires (SiNWs) through hydrothermal process. First, as prepared MoS 2 /SiNWs heterostructure was characterized by using Raman spectroscopy, Scanning Electron Microscopy (SEM) and by means of the Energy-Dispersive X-ray spectroscopy (EDX). Second, the photocatalytic activity ofsynthesizedMoS 2 /SiNWs photocatalyst was systematically evaluated for the decoloration of methylene blue (MB) under visible light irradiation. It was found that MoS 2 /SiNWs heterostructure exhibited excellent photocatalytic activity against this dye compared with synthesized SiNWs films. Also, it was found that after irradiation during 180 min, the MoS 2 /SiNWs film exhibited the highest photocatalytic efficiency (90%), in comparison to SiNWs (62%). Finally, it is assumed that the photocatalytic activity improvement was attributed to visible light absorption improvement, the enhancement of the photogenerated electron-hole pair's separation efficiency. Moreover, thanks to the nanoflowers structure assembled by nanosheets with few layers, the specific surface area was increased offering more sites for MB pollutant adsorption. [ABSTRACT FROM AUTHOR]