Enhancement of Photoelectrochemical Hydrogen Evolution of P-Type Silicon Nanowires Array by Loading MoS2

To improve photoelectrochemical properties of Si nanowires (SiNWs), MoS2/SiNWs is prepared via two-step method. SiNWs is synthesized by metal−catalyzed electroless etching (MCEE) method and MoS2 is subsequently deposited onto SiNWs through the direct thermal decomposition method. MoS2 is introduced as both light absorber and catalyst for hydrogen evolution reaction (HER). Moreover, it forms a heterojunction with SiNWs that contribute to the charge separation. Herein, MoS2/SiNWs attains excellent hydrogen evolution reaction (HER) catalysis with onset potential of 55 mV. A photocurrent density of 25 mA cm− 2 at −1.0 VRHE were achieved under simulated solar illumination, which is about 6 times higher than that of SiNWs, and the carrier concentration is increased by 100−fold. The enhanced photocatalytic activity of MoS2/SiNWs toward HER is attributed to the Schottky junction at the interface, which enhances the photo−generation of electron−hole pairs and suppresses the charge recombination, making them promising earth−abundant alternatives to noble metal−based photocathode for HER.