Fabrication of BiVO₄ submicron rods photoanodes through phase transition assisted by Mo doping

The contradiction between the optical absorption depth and carrier diffusion length has emerged as a significant problem constraining the performance of BiVO4 photoanodes. Fabricating a one-dimensional (1D) structure is considered a promising strategy to address the above problem. However, the synthesis of BiVO4 photoanodes consisting of 1D monoclinic scheelite remains a great challenge. In this study, a 1D molybdenum (Mo) doped BiVO4 photoanode (Mo:1D-BVO) consisting of monoclinic scheelite BiVO4 submicron rods (SMRs) through a phase transition from a 1D tetragonal zircon BiVO4 precursor was successfully prepared. It was found that Mo doping could lower the phase transition barrier from tetragonal zircon to monoclinic scheelite BiVO4. Due to the Mo:1D-BVO photoanode's remarkable light absorption efficiency, efficient carrier separation, and superior conductivity, it yields a photocurrent density of 2.08 mA cm(-2) at 1.23 V versus reversible hydrogen electrode (RHE), which is 3.5 times higher than that of pristine BiVO4. Upon the introduction of the co-catalyst, the photocurrent density of Co-Pi/Mo:1D-BVO attains 3.18 mA cm(-2) at 1.23 V vs. RHE, accompanied by a carrier separation efficiency of 91%. Our study introduces a novel approach for the production of remarkably efficient 1D monoclinic scheelite BiVO4 photoanodes.