A Universal AgP₂ Nanowire Modification Method Enabling Durable Anodes for Alkaline Seawater Electrolysis

Alkaline seawater electrolysis represents a prospective route for sustainable hydrogen production, yet the high Cl^- concentration in seawater causes persistent anodic corrosion, severely limiting long-term operation. Here, a scalable and universal modification method is proposed to construct corrosion-resistant oxygen-evolution anodes through silver nanowire loading and subsequent phosphating treatment. This method is applicable to multiple anode platforms, such as Ni mesh, NiFe-LDH/Ni mesh, and NiCo-LDH/Ni mesh. During operation, AgP₂ nanowires are in situ converted into a continuous AgCl network that immobilizes Cl^-, while simultaneously generated PO₄^3- is adsorbed on the electrode surface, collectively establishing a negatively charged anion-protective layer that electrostatically repels free Cl^- and thus significantly suppresses corrosive attack. As a result, the optimized NiFeP@AgP₂ NWs anode operated stably for over 600 h in a highly saline alkaline electrolyte and exceeded 1000 h in 1 M NaOH + 0.5 M NaCl electrolyte, with negligible performance decay. Furthermore, the magnified electrodes (∼100 cm²) fabricated by using this approach enable stable operation in an alkaline seawater electrolyzer with low energy consumption.