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.