Synergistic modification of <scp>Cu₃V₂O₈</scp> nanosheeta photoelectrodes with <scp>NiFe</scp> and <scp>NiO_<i>x</i></scp> for efficient and ultra‐stable photoelectrochemical water oxidation

Abstract BACKGROUND The design and development of environmentally friendly, efficient, and stable photoelectrodes are crucial for advancing photoelectrochemical (PEC) water‐splitting technology. RESULTS In this study, we report a novel strategy for the preparation of copper vanadate (Cu 3 V 2 O 8 ) nanosheet arrays using a low‐temperature solution method. Notably, this is the first instance of directly growing Cu 3 V 2 O 8 nanosheet arrays on FTO (fluorine‐doped tin oxide) conductive glass. The morphology of the developed nanosheet arrays offers a larger specific surface area and improved bulk charge separation efficiency, which are desirable characteristics for PEC water‐splitting applications. To further enhance the stability and PEC performance of the Cu 3 V 2 O 8 nanosheets, a synergistic modification strategy was employed. This approach involved the deposition of an NiO x passivation layer and the incorporation of an NiFe co‐catalyst. The synergistic modification strategy significantly improved the PEC performance and stability of the Cu 3 V 2 O 8 nanosheet arrays. The modified photoelectrode achieved an impressive photocurrent of 0.67 mA cm −2 at 1.23 V versus a reversible hydrogen electrode and demonstrated stability for over 80 h of operation. CONCLUSION This work provides a new, low‐cost, and effective strategy for the preparation of efficient and stable photoelectrodes for PEC water splitting, which is a crucial step towards the development of environmentally friendly and sustainable energy technologies. © 2025 Society of Chemical Industry (SCI).