Theory‐Guided Design of Surface‐Enhanced Ni–Mn Diatomic Site Catalysts for Efficient Seawater Electrolysis via the Degradation of High Ionization Potential Organic Pollutants

Abstract In response to energy shortages and hard‐to‐degrade chemical pollution, especially high ionization potential (IP) organic pollutants, this study developed a novel photoelectrocatalyst, Ni‐Mn@OBN, for degrading IP pollutants in seawater and generating hydrogen. Incorporating Ni–Mn dual atoms into an O‐doped boron nitride (OBN) framework, Ni‐Mn@OBN, shows excellent stability and HER performance. Density functional theory (DFT) analysis revealed its low Gibbs free energy change (Δ G H* = 0.03 eV) for HER, outperforming Pt (111). Achieving an ultralow overpotential of 43.8 mV at 500 mA cm⁻ 2 under AM 1.5G, simulated light surpasses commercial Pt/C catalysts. High IP pollutants enhance hydrogen evolution rates, indicating a synergistic effect. Theoretical calculations elucidated the interplay between seawater electrolytes and high IP values on the photoelectrocatalytic performance. Ni‐Mn@OBN demonstrated excellent stability and a solar‐to‐hydrogen (STH) efficiency of 3.72%, offering a sustainable solution for marine pollution control and clean energy production.