Efficient Photoelectrochemical Water Splitting of BiVO₄ Nanosheets Vertically Synthesized on WO₃ Nanorods

BiVO₄ nanosheets (NSs) have recently attracted great attention as a promising visible-light responsive photocatalyst for photoelectrochemical (PEC) water splitting. The PEC reactivity of BiVO₄ NSs has been further improved by employing heterostructures, such as BiVO₄/WO₃ and BiVO₄/TiO₂, which enhance the separation and subsequent transfer of photogenerated electron-hole pairs via a built-in junction potential. To fully take advantage of the heterojunction effects of PEC reactions, the size and configuration of BiVO₄ NSs on nanostructure matrices, such as WO₃ nanorod (NR) substrates, should be optimized in a controllable manner. In this work, we report the synthesis and PEC performance of vertically-aligned BiVO₄ NSs on WO₃ NRs. WO₃ NRs were synthesized via hydrothermal reaction and decorated by BiVO₄ NSs through drop casting. The heterostructure of BiVO₄ NSs on 1D WO₃ NRs exhibited significantly promoted PEC performance because of beneficial heterojunction effects, improved photoabsorption, and increased reaction surface area. In addition, the heterostructure of BiVO₄ NSs/WO₃ NRs formed a desirable heterojunction leading to effective photogenerated charge transfer dynamics. Our study indicates that vertically-aligned BiVO₄ NSs on WO₃ NRs are promising candidates as nontoxic, inexpensive, and stable photoanodes for PEC water splitting.<br/><br/><b>Keywords:</b> photoelectrochemical, tungsten oxide, bismuth vanadate, nanorods, nanosheets<br/>* Corresponding author: [email protected]