Constructing Nanosphere Heterogeneous Structure of Ir‐Doped CoP ₃ and WO ₂ with Interfacial Coupling for Overall Alkaline Water/Seawater Splitting

Developing durable bifunctional electrocatalysts capable of operating efficiently across water/seawater electrolytes remains a challenge for sustainable hydrogen production. Herein, a hierarchical Ir-CoP₃/WO₂ heterostructure is demonstrated derived from ZIF-67. Benefiting from the dual modulation of Ir doping and WO₂ interfacial coupling, the optimized catalyst achieves overpotentials of 249 mV for oxygen evolution reaction (OER) and 44 mV for hydrogen evolution reaction (HER) at 10 mA cm^-2 in 1 M KOH. Remarkably, the integrated electrolytic cell requires voltages of 1.526 V (1 M KOH), 1.527 V (1 M KOH + 0.5 M NaCl), and 1.540 V (1 M KOH + seawater) to drive 10 mA cm^-2 current density, while maintaining exceptional durability (>100 h@100 mA cm^-2) across all media. Theoretical calculation results show that the doping of Ir regulates the position of the d-band center of CoP₃ and CoOOH (reconstructed from CoP₃ in OER), optimizes the adsorption/desorption of the intermediate, and reduces the reaction energy barrier. Meanwhile, the interfacial coupling of WO₂ accelerates electron transfer, enhances the conductivity of the catalyst, and improves the HER/OER performance of the catalyst through a synergistic effect. Therefore, this work provides a new idea for designing metal-doped heterostructures for electrochemical decomposition of water/seawater.