Boosted photoelectrochemical water splitting activity by construction of a novel FeVO4/AgVO3 p-n heterostructure

Abstract

FeVO₄ is recognized as a potential photoelectrode material on account of its relatively narrow bandgap and suitable conduction and valence band positions. However, its photoelectrochemical water splitting performance remains unsatisfactory owing to rapid carrier recombination and poor charge transport capabilities. Herein, a novel p-n FeVO₄/AgVO₃ heterostructure photoanode was developed by depositing p-type AgVO₃ nanowires onto n-type FeVO₄ nanoporous structures, boosting the PEC properties of the base material. The incorporated AgVO₃ nanostructures enhance light absorption in the visible spectrum, facilitate effective electron-hole separation through optimized interfacial charge transport pathways, and simultaneously extend the carrier lifetime. The built-in electric field in the p-n heterostructure promotes more effective separation and directional motion of photoinduced charge carriers. As a result, the transient photocurrent density of the FeVO₄/AgVO₃ heterojunction photoanode reaches 0.22 mA cm⁻², which is 3.35 times that of bare FeVO₄ (0.06 mA cm⁻²). Notably, the incorporation of AgVO₃ nanowires significantly improves the photostability of the FeVO₄ photoanode. This work provides a feasible strategy from the perspective of interface engineering for designing high-performance FeVO₄-based photoelectrodes to enhance photoconversion efficiency.