Slag-Source Fast Photo-Deposition for Enhanced Water Oxidation Photoanode

The development of high-performance and low-cost cocatalysts for efficient oxygen evolution reaction (OER) has significant practical implications for photoelectrochemical water splitting. In this work, a high-performance FeOOH/BiVO4 photoanode on BiVO4 was successfully prepared by a facile and fast photodeposition method using steel slag as the raw material. This approach not only improved the performance of the BiVO4 photoanode, but also utilized the resource of steel slag. The photocurrent of the FeOOH/BiVO4 photoanode reached 3.26 mA/cm2 at 1.23 V vs. RHE, exceeding that of BiVO4 by 2.8 times. In addition, the FeOOH/BiVO4 achieved a cathodic onset potential shift of ∼305 mV compared to the pure BiVO4. Furthermore, the stability of the FeOOH/BiVO4 was significantly enhanced. The modification of FeOOH not only promotes charge separation, but more importantly, it provides abundant active sites and improves surface reaction kinetics, thereby significantly accelerating the water oxidation process. This research not only provides new ideas and avenues for the advancement of low-cost and high-performance OER cocatalysts, but also makes a positive contribution to the utilization of industrial waste resources.