Synergistic electronic redistribution and in-situ surface reconstruction of N,P-Ag for efficient HER and OER in chlorine-resistant alkaline seawater electrolysis

Bifunctional N,P-codoped Ag catalyst achieves outstanding seawater electrolysis performance. • Enhanced HER via optimized H adsorption and H–H coupling enabled by N,P codoping. • In situ generated PO 4 3− activates lattice oxygen, lowers OER barrier, suppresses Cl − adsorption. Herein, we present a bifunctional N,P-co-doped Ag (N,P–Ag) catalyst synthesized via one-step electrodeposition for efficient alkaline seawater splitting. The catalyst achieves low overpotentials of 260 mV@50 mA cm −2 for oxygen evolution reaction (OER) and 49 mV@10 mA cm −2 for hydrogen evolution reaction (HER), along with excellent reaction kinetics and long-term stability (sustained operation for 200 h at 100 mA cm −2 ). DFT calculations disclose that N, P co-doping enhances HER activity by disrupting Ag's electronic configuration to create new hybrid orbitals and delocalized electronic states, which in turn optimize H* adsorption and accelerate H–H bond formation. In-situ Raman spectroscopy captures the surface restructuring process during OER that leads to the formation of the active phase PO 4 3- -AgO. The lattice oxygen-mediated mechanism (LOM) enables lattice oxygen to participate directly in the OER process, helping to optimize the energy levels of intermediate reactions and weaken Cl − adsorption, thereby effectively suppressing chloride ion corrosion. This work demonstrates a combined approach of non-metallic doping for electronic tuning and in-situ anion modification for lattice oxygen activation, providing a viable route to achieve efficient and corrosion-resistant seawater electrolysis. By modulating electron conduction via N/P doping, localized charge enrichment zones are created around Ag atoms as HER-active sites, while in situ-generated PO 4 3− activates lattice oxygen, lowering the reaction barrier and inhibiting chloride corrosion. Download: Download high-res image (357KB) Download: Download full-size image