BiVO₄ Photoanodes Modified with Synergetic Effects between Heterojunction Functionalized FeCoO_x and Plasma Au Nanoparticles

The design and development of high-performance photoanodes are the key to efficient photoelectrochemical (PEC) water splitting. Based on the carrier transfer characteristics and localized surface plasmon resonance effect of noble metals, gold nanoparticles (AuNPs) have been used to improve the performance of photoanodes. In this study, a novel efficient composite BiVO₄/Au/FeCoO_x photoanode is constructed, and the quantitative analysis of its performance is systematically conducted. The results reveal that the co-modification of AuNPs and FeCoO_x plays a synergetic role in enhancing the absorption of ultraviolet and visible light of BiVO₄, which is mainly attributed to the localized surface plasmon resonance effect induced by AuNPs and the extended light absorption edge position induced by the BiVO₄/FeCoO_x heterojunction. The BiVO₄/Au/FeCoO_x photoanode exhibits a high photocurrent density of 4.11 mA cm⁻² at 1.23 V versus RHE at room temperature under AM 1.5 G illumination, which corresponds to a 299% increase compared to a pristine BiVO₄ photoanode. These results provide practical support for the design and preparation of PEC photoanodes decorated with AuNPs and FeCoO_x.