Nanostructured WO3/BiVO4 heterojunction films embedded with Au nanoparticles for efficient photoelectrochemical water splitting

The application of BiVO 4 , a promising photoelectrochemical (PEC) material, has been severely limited by its low charge separation and light absorption efficiency. Though its performance can be improved when it is coupled with WO 3 to form the WO 3 /BiVO 4 heterojunction, its absorption band in visible light region is still narrow and the photoelectric conversion efficiency is still low. In this work, we report the fabrication of nanostructured WO 3 /BiVO 4 heterojunction film embedded with Au nanoparticles as photoelectrode for PEC application. The photoelectrode exhibited improved PEC performance with an incident photon-to-electron conversion efficiency (IPCE) value of 41.7% at 365 nm. The significantly enhanced performance was attributed to enhanced photogenerated charge carrier separation from large heterojunction interface based on nanostructured WO 3 and improved light absorption arising from the surface plasmon resonance effect of Au nanoparticles. Graphic abstract