Direct growth of Bi2S3 nanorods onto the Bi2MoO6 nanoflakes: A promising heterostructure for efficient photoelectrochemical water-splitting application

Fabrication of heterostructure promises a potential approach to increase the hydrogen production performance of photoelectrodes under solar light irradiation. Herein, a two-step hydrothermal method was introduced to grow directly Bi2S3 nanorods onto the Bi2MoO6 nanoflakes to form Bi2MoO6/Bi2S3 heterostructure. This work is aimed to synthesize heterostructure photoelectrode for photoelectrochemical water splitting application. The as prepared photoelectrodes were analyzed by using X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectra, and UV-vis spectroscopy. As a result, the heterostructure Bi2MoO6/Bi2S3 indicated a dramatic improvement in the PEC properties (1.41 mA/cm2). From the X-ray photoelectron spectroscopy valence band measurement, the suitable bandgap between Bi2MoO6 and Bi2S3 can promote charge transfer across the junction interface and suppress electron-hole recombination. Furthermore, coupling a narrow bandgap material Bi2S3 with Bi2MoO6 can form a type II-heterostructure, leading to enhancement of the light absorption under visible light irradiation. This work provides a promising and efficient photoanode for light harvesting and hydrogen production.