Constructing Nanosphere Heterogeneous Structure of Ir-Doped CoP and WO 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-CoP/WO heterostructure is demonstrated derived from ZIF-67. Benefiting from the dual modulation of Ir doping and WO 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 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 current density, while maintaining exceptional durability (>100 h@100 mA cm) across all media. Theoretical calculation results show that the doping of Ir regulates the position of the d-band center of CoP and CoOOH (reconstructed from CoP in OER), optimizes the adsorption/desorption of the intermediate, and reduces the reaction energy barrier. Meanwhile, the interfacial coupling of WO 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.