Improving the charge properties of the WO3 photoanode using a BiFeO3 ferroelectric nanolayer

Abstract

Tungstic oxide (WO₃) is a promising visible-light-responsive photoanode material, but it has poor charge transport and collection properties. In this study, a WO₃/BiFeO₃ core/shell photoanode (WO₃/BFO) with enhanced photoelectrochemical (PEC) performance was successfully prepared using a facile spin-coating method. The optimal WO₃/BFO shows an excellently enhanced and stable photocurrent density of ∼2.83 mA cm⁻² at 0.6 V vs. Ag/AgCl, which is ∼244% more than WO₃ under AM 1.5 illumination. The results of Mott–Schottky tests, intensity modulated photoelectrochemical spectroscopy and transient photocurrent decay indicated that the BFO ferroelectric nanolayer significantly enhances the charge density of the WO₃/BFO, and improves its charge transport and separation property and charge lifetime, which could be the reason for the enhanced PEC activity of WO₃/BFO.