Enhancing Water Splitting Activity of Photocathode Using MoS2 Flakes Deposited on Copper Oxide Nanowire

Abstract

In this work, we report the synthesis of copper oxide (CuO) nanowires on indium tin oxide (ITO) coated with a few–layers of MoS2 flakes by the thermal annealing and metal–organic chemical vapour deposition (MOCVD) methods at a temperature of 200 °C. As a result, the CuO/MoS2 photocathode gave the maximum photocurrent density (PCD) of −9.8 mA/cm2 (η = 0.75%) at –1.2 V (vs. RHE), which is higher than that of the pristine CuO nanowires photocathode (−6.08 mA/cm2, η = 0.44%). The high PCD of CuO/MoS2 photocathode is attributed to the high stability and more active sites of MoS2 flakes, lowering the electrochemical proton reduction over potential, as well as the built–in potential of CuO–MoS2 heterojunction, and minimizing the dark current of the photoelectrochemical (PEC) cell. Based on these findings, we advance the fabrication of the hybrid PEC device (MoS2 and traditional photocatalytic materials) for enhancing efficient hydrogen evolution reaction.