FeOOH nanolayers decorated on oxygen-vacancy-containing BiVO 4 for efficient photoelectrochemical degradation of Rhodamine B

Abstract

The short carrier diffusion length, the trade-off between sufficient light absorption and efficient charge separation of BiVO4 photoelectrode often leads to poor photoelectrochemical (PEC) degradation performance. In this paper, we firstly designed a method of combining oxygen vacancies (Ov) with cocatalyst FeOOH for synergistic improve BiVO4 PEC degradation performance. After introducing Ov resulted from hydrothermal method, the photocurrent density value reaches 0.54 mA/cm2 at 1.23 V vs. RHE by the enhanced of carrier density and the broaden of light absorption, 1.38 times higher than that of pure BiVO4 (0.39 mA/cm2 at 1.23 V vs. RHE). As expected, the as-synthesized BiVO4-Ov/FeOOH exhibits enhanced stability and a remarkable photocurrent density of 1.18 mA cm2 at 1.23 V vs. RHE under AM 1.5G illumination. In addition, a significant PEC degradation performance of 85% were reached, which is about 1.7 times than BiVO4-Ov. The results demonstrate that the Ovs can be effectively preserved by the coating of a thin FeOOH layer, leading to a photoelectrode of enhanced photocurrent and stability.