Boosting the solar water oxidation performance of BiVO4 photoanode via non-stoichiometric ratio drived surface reconstruction

Developing high-quality BiVO4 photoanode with superior photoelectrochemical activity is of great importance to assure its viable application in solar energy storage. Herein, we demonstrate for the first time the synthesis of a dense and uniform BiVO4 film with active surface that could be reconstructed during the water oxidation measurements. The BiVO4 with thickness of around 300 nm exhibits the highest bulk separation efficiency of 74% at 1.23 V-RHE and photocurrent density up to 4.02 mA cm(-2) (1.23 V-RHE), which relates with the surface reconstruction of the photoanode during the photoelectrochemical (PEC) operation. The surface transport effi-ciency and bulk separation efficiency is 2.2 and 1.2 times higher than that of none-surface-reconstructed samples, respectively. Further structural characterizations reveal that the surface reconstruction could be driven by the non-stoichiometric surface ratio of Bi and V in BiVO4. We thus believe present work provides an effective alternative to construct active surfaces of photoelectrodes for improved water oxidation performances.

Automated summary

In this study, a dense and uniform BiVO4 film with active surface that could be reconstructed during the water oxidation measurements was synthesized for the first time. The BiVO4 film with a thickness of around 300 nm exhibited high bulk separation efficiency and photocurrent density, which can be attributed to the surface reconstruction during the photoelectrochemical operation.