Abstract
A highly efficient narrow-band-gap photoelectrode plays a vital role in achieving solar-to-hydrogen conversion. In this work, we report a novel Sb(2)Se(3)/CdSe/Pt photocathode, and the activity of this photocathode was studied. The photocathode was fabricated via electrodeposition followed by annealing and surface modification with a CdSe monolayer and Pt cocatalyst. The photocurrent density of the Sb(2)Se(3)/CdSe/Pt photocathode is ca. -6.9 mA cm(-2) at -0.2 V(RHE) in near-neutral pH buffered solution, which is 2.3 times that of the Sb(2)Se(3)/Pt photoelectrode. The enhanced photoelectrochemical (PEC) performance is owing to the successful construction of the Sb(2)Se(3)/CdSe p-n heterojunction, which contributes to effective charge separation and transfer. Additionally, the effect of the Sb(2)Se(3) layer thickness on the photocurrent was investigated, which suggests that an appropriate thickness of Sb(2)Se(3) layer is necessary for sufficient light absorption and efficient hole transport. This work develops a novel Sb(2)Se(3)-based p-n heterojunction photocathode using a facile fabrication approach, which provides a practical pathway for developing cost-effective PEC devices with wide solar spectrum utilization.