Nanoporous BiVO4 nanoflake array photoanode for efficient photoelectrochemical water splitting

BiVO4 has been considered as a promising material for photoelectrochemical (PEC) hydrogen production. To improve the charge transport performance of BiVO4 photoanodes, it is necessary to develop nanostructured BiVO4 array photoanodes. In the present study, an in situ transformation strategy (WO3 -> Bi2WO6 -> BiVO4) was designed and developed to fabricate a nanoporous BiVO4 nanoflake array (NFA) film. As revealed from the characterization results, the BiVO4 nanoflakes were vertically grown on FTO substrates. Note that the nanoflakes were composed of wormlike-shaped particles, thereby forming a nanoporous structure. The as-prepared films as photoanodes exhibited excellent visible-light PEC performance. Under visible light illumination, the photocurrent density of the BiVO4 NFA photoanode without a cocatalyst was 1.0 mA cm(-2) at 1.23 V-RHE, comparable to the reported BiVO4 array photoanode without cocatalysts. In this study, a novel and simple way was proposed to fabricate high-quality BiVO4 array photoanodes.