Sb2Se3 nanorods in the confined space of TiO2 nanotube arrays facilitating photoelectrochemical hydrogen evolution

Abstract

Antimony selenide (Sb2Se3) is a very handy light-absorbing material in photochemical devices based on TiO2 nanotube arrays (TNT), but it has some problems with anisotropy and agglomeration. Large particles of antimony selenide instead impede photon transport and are susceptible to photocorrosion instability, making it crucial to develop a strategy for the directional growth of rod-shaped Sb2Se3 arrays. Herein, we successfully achieved the deposition of Sb2Se3 inside the tube of TNT by pulsed electrodeposition strategy to obtain the oriented Sb2Se3 nanorod arrays for efficient photoelectron transport. The conductive atomic force microscopy indicates the enhanced electron transfer performance. The UV spectral conclusion shows that the deposition of rod-shaped Sb2Se3 enhances the UV–vis diffuse absorption of TiO2, meanwhile, TNT acts as a shell to protect antimony selenide and effectively prevents its photocorrosion phenomenon. Therefore, the photocurrent density of TNT/Sb2Se3 NRs is 6.79 times as that of bare TNT. The Pt/TNT/Sb2Se3 NRs electrode exhibits a photocurrent density of 2.6 mA cm−2 (−0.2 V RHE) and considerable hydrogen evolution performance. In addition, the Surface-Enhanced Raman effect (SERS) originated from this Sb2Se3 array, is first observed, which is expected to reduce the cost of SERS technology.