Preparation of BiFeO3 cover layer on radially aggregated CuO nanosheet clusters photocathode for the enhanced visible-light activity in PEC application

초록

This study focuses on the development of high-performance photocathode materials, specifically designed for efficient and stable photoelectrochemical (PEC) hydrogen production under visible light. A heterostructured CuO@BiFeO<inf>3</inf> (CuO@BFO) system was fabricated via a two-step process: hydrothermal synthesis of CuO, followed by spin-coating of a BFO precursor solution, and annealing to optimize crystallinity and interface quality. Comprehensive characterizations – including morphological, structural, optical, and electrochemical evaluations – were performed to elucidate the properties of the resulting heterostructures. The formation of a heterojunction between CuO and BFO significantly improved the charge separation efficiency, light absorption, and surface reactivity, thereby enhancing the overall PEC performance. Notably, the CuO@BFO6 photocathode showed the highest photosensitivity, reaching a photocurrent density of -1.262 mA·cm−2 at 0.0 V vs. RHE under AM 1.5 G illumination. This represents a significant improvement over the pristine CuO or BFO electrodes. Furthermore, the CuO@BFO6 photocathode retained 50.1 % of its initial photocurrent after 3600 s of continuous operation, significantly outperforming the bare CuO, which retained only 39.4 %. The improved activity and stability were attributed to the enhanced interfacial charge transfer at the electrode/electrolyte junction and the photo-corrosion inhibition due to the synergistic role of BFO. These findings highlight the potential of the CuO@BFO heterostructure as a promising candidate for sustainable PEC water splitting application. © 2025 Elsevier Ltd.

키워드