Ternary WO3/Porous‐BiVO4/FeOOH Hierarchical Architectures: Towards Highly Efficient Photoelectrochemical Performance

Abstract

AbstractDeveloping photoanodes showing both a high solar harvesting efficiency and efficient charge separation/transfer is recognized as one of the key challenges for water splitting. In the presented work, we report a strongly coupled ternary WO3/porous‐BiVO4/FeOOH hierarchical architecture as photoanode for high PEC performance,which was constructed by unique foaming‐assisted electro‐spraying of porous BiVO4 frameworks and photodeposition of a FeOOH layer, respectively. As a proof of concept, the as‐fabricated WO3/porous‐BiVO4/FeOOH photoanode yielded a photocurrent density of ∼4.4 mA cm−2 at 1.23 V vs. RHE, ∼4 and 10 times higher than that of the BiVO4 and WO3 counterparts, respectively. Because of the surface passivation of FeOOH, the onset potential could be substantially reduced to ∼200 mV in the presence of sacrificial agent under AM 1.5G (100 mW cm−2) simulated sunlight illumination, which was lowered by ∼100 mV in comparison to those of BiVO4 and WO3 analogues. The mechanism for the enhanced PEC activities of ternary WO3/porous‐BiVO4/FeOOH hierarchical architectures was proposed.