FeOOH decorated Sb2Se3@CdxZn1-xS core-shell nanorod heterostructure photocathode for enhancing photoelectrochemical performance

Abstract

In this work, a core-shell heterostructure Sb2Se3@CdxZn1-xS photocathode was constructed on the Fluorine-doped Tin Oxide (FTO) by Vapor Transport Deposition (VTD) and hydrothermal method, then β-FeOOH was deposited on the surface of Sb2Se3@Cd0.8Zn0.2S. The investigation indicates that Sb2Se3@CdxZn1-xS has a one-dimensional (1D) nanorod structure, which can provide a fast carrier transmission channel. The introduction of a CdxZn1-xS shell can accelerate the charge separation of Sb2Se3 and type-II heterojunction between them can enhance the electron migration efficiency of Sb2Se3. Using β-FeOOH as the protective layer can not only protect the ternary photocathode from photocorrosion, but also act as a cocatalyst to enhance surface reaction kinetics. Photoelectrochemical (PEC) tests found that the composite photocathode Sb2Se3@Cd0.8Zn0.2S/β-FeOOH achieves a higher photocurrent density (0.252 mA/cm2), which is about 21 times higher than that of pure Sb2Se3 nanorod photocathode (0.012 mA/cm2) under the same condition, besides, it also exhibited more excellent stability during 1 h hydrogen production. This work provides an effective way to design and fabrication of nanostructures for high-efficiency water splitting photoelectrodes.