Amorphous iron (III)-borate decorated electrochemically treated-BiVO4 photoanode for efficient photoelectrochemical water splitting

BiVO4 has attracted widespread attention as a promising semiconductor material for recent year. However, poor water oxidation kinetics and severe surface charge recombination are still the bottlenecks, which significantly hinders the practical solar-to-hydrogen conversion. In this work, we successfully decorated iron-borate (FeBi) co-catalyst on the surface of electrochemical treated-BiVO4 (E-BVO, via 10 s), and the obtained FeBi/E-BiVO4 heterostructure drastically enhances the PEC water splitting performance. The optimal sample exhibits an excellent photocurrent density of 3.24 mA/cm2 at 1.23 VRHE, a 600% increase over the pristine BiVO4 (0.46 mA/cm2). The applied bias photo-to-current efficiency (ABPE) has been increased up to 1.35%, since FeBi co-catalyst and E-BVO contributes to expose more active sites and offer rich oxygen vacancies, respectively, which efficiently boosted the charges transfer and separation efficiencies. Therefore, this work will provide an alternative route to realize the efficient solar-to-hydrogen conversion.