Stable and highly efficient MoS2/Si NWs hybrid heterostructure for photoelectrocatalytic hydrogen evolution reaction

We report, the fabrication of molybdenum disulphide (MoS2) wrapped silicon nanowires (Si NWs) for visible light driven water splitting applications. The morphological and elemental studies ensure the vertical alignment of Si NWs wrapped with 2D layered MoS2. The photoelectrocatalytic (PEC) results evidence the significant enhancement in performance of MoS2/Si NWs based hybrid photocathode with similar to 300 mV (under reversible hydrogen electrode (RHE)) anodic shift in onset potential as that of pristine Si NWs (+0.194 V vs. RHE), and the current density of -26.5 mA/cm(2) was achieved at the applied bias of 0 V vs. RHE. Further, the electrochemical impedance studies ensure the interface resistance-free charge transfer between Si NWs and electrolyte via 2D MoS2 layer which provokes rapid hydrogen production. The wrapping of Si NWs with MoS2 protects the superlative photocathode from harsh acid electrolyte environment. The overgrown MoS2 triangular particles with active sulphur edge sites are found to eventually augment the solar hydrogen evolution rate. Further, the PEC performance of our MoS2/Si NWs is also comparable with stable Pt/Si NWs photoelectrode. It is note-worthy that, MoS2/Si NWs hybrid heterostructure would be a-potential candidate in future large scale, low cost and day-to-day solar water splitting applications. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.