3D interconnected nanoporous Ta3N5 films for photoelectrochemical water splitting: thickness-controlled synthesis and insights into stability

Solar-driven photoelectrochemical (PEC) water splitting is a promising technology for sustainable hydrogen production, which relies on the development of efficient and stable photoanodes oxidation reaction. The thickness microstructure semiconductor films are generally crucial to their PEC properties. Herein, three-dimensional (3D) interconnected nanoporous Ta3N5 film with controlled were successfully fabricated via galvanostatic anodization NH3 nitridation. porous nanoarchitectures (NAs) 900 nm in showed highest performance due optimal light-harvesting charge separation. Compared hole-induced photocorrosion, electrochemical at high anodic potentials resulted severer degradation Ta3N5. Although surface oxide layer deteriorated could be removed by re-treatment, was only partially recovered. As an alternative, anchoring dual-layer Co(OH)x/CoOOH co-catalyst shell NAs demonstrated substantially enhanced stability. Overall, this work provides reference controllably fabricate 3D Ta3N5-based optimizing light absorption, hole extraction, separation utilization.