Boosting Charge Separation and OER Kinetics in BiVO۴ Photoanodes via FeSe۲ Cocatalyst: A Pathway to Efficient Solar Water Splitting

Developing efficient photoanodes for photoelectrochemical (PEC) water splitting is crucial for sustainable hydrogen generation. This study presents a novel FeSe۲/BiVO۴ composite photoanode designed to address the inherent limitations of BiVO۴ in solar-driven water oxidation. Through a facile hydrothermal synthesis and drop-casting approach, FeSe۲ nanoparticles were successfully integrated with BiVO۴, significantly enhancing charge separation and oxygen evolution reaction (OER) kinetics. Under AM ۱.۵G illumination, the optimized FeSe۲/BiVO۴ photoanode delivered an exceptional photocurrent density of ۳.۸۴ mA/cm² at ۱.۲۳ V vs. RHE—a ۱۵۸% improvement compared to pristine BiVO۴ (۱.۴۹ mA/cm²). Electrochemical impedance spectroscopy confirmed a ۶۹% reduction in charge transfer resistance (from ۶۹۸.۴ to ۲۱۴.۱ Ω), demonstrating FeSe۲'s role in facilitating interfacial charge transport. Furthermore, the composite exhibited remarkable stability, retaining ۹۰.۶% of its initial performance after ۱ hour of continuous operation, outperforming unmodified BiVO۴ (۸۴.۶% retention). These results highlight FeSe۲ as an effective co-catalyst for BiVO۴, offering a promising strategy to advance PEC water-splitting technologies.

کلیدواژه ها:

Photoanode ، Photoelectrochemical water splitting ، Oxygen evolution reaction ، Bismuth vanadate ، Iron diselenide