Enhanced photoelectrochemical hydrogen production via linked BiVO4 nanoparticles on anodic WO3 nanocoral structures

Abstract

Morphological properties of photoanodes are crucial for improving their photoelectrochemical (PEC) performance. In this study, we fabricated bismuth vanadate (BiVO₄) nanoparticles (NPs) with an optimal size of ∼10 nm, as well as nanowires composed of NPs on anodized tungsten trioxide (WO₃) nanocoral structures. The linked BiVO₄ NPs were decorated by spin-coating, with the amount of the BiVO₄ precursor being controlled. Subsequently, the concentrations of Bi and V in the BiVO₄ precursor were determined. An optimized concentration of 0.3 M Bi and V for the linked BiVO₄ NPs/WO₃ nanocoral heterostructure led to enhanced photocurrent density and hydrogen gas-production compared to those of the pristine WO₃ nanocorals, yielding results that were 2.4 times higher. In particular, the incident photon-to-current conversion efficiency value at 410 nm improved by 8.3 times, as the linked BiVO₄ NPs attained efficient absorbance of visible light and a sufficient electron transfer pathway.