FeF2/BiVO4 heterojuction photoelectrodes and evaluation of its photoelectrochemical performance for water splitting

A novel type of semiconductor, FeF2/BiVO4 was successfully prepared by electric deposition of precipitating FeF2 onto the surface of BiVO4 electrode so as to generate hydrogen during water splitting process. Via a list of trial catalyzed with FeF2/BiVO4 containing different contents of FeF2, the most efficient catalyst was optimised as the one with depositing FeF2 for 20 circles. Consequently, it able to produce the amount of 635.5 mu mol H-2 within 3 h, three times more than BiVO4 alone. The optimal photoanode of FeF2/BiVO4 exhibits a photocurrent density of 2.49 mA cm(-2) at 1.23 V vs. RHE and an IPCE value of 28% at 450 nm, which are 2.26 and 3.73 times as much as pure BiVO4 photoanode, respectively. It is mainly attributed to the enhanced capacities of light absorption in the visible range and transfer of photo-generated carriers as well as separation between electrons and holes after the combination of BiVO4 and FeF2. At the same time, it offers a novel idea toward the project of solar water splitting.