Simultaneous modulation of interfacial electronic structure and bubble dynamics: a sea-urchin-like NH₂-MIL-88B(Fe)...

Simultaneously optimizing electronic structure and oxygen-bubble release kinetics remains a key yet challenging issue for seawater oxygen evolution reaction (OER). Herein, we report a sea-urchin-like NH₂-MIL-88B(Fe) metal-organic framework@NiFe-layered double hydroxide (NH₂-MIL-88B(Fe)@NiFe-LDH) nano-heterojunction electrocatalyst that integrates an intrinsic built-in electric field with superhydrophilic/superaerophobic surface characteristics, thereby enhancing intrinsic catalytic activity and accelerating bubble detachment. In situ Raman spectroscopy reveals that heterojunction-induced interfacial charge transfer accelerates surface reconstruction, leading to the rapid generation of highly active NiOOH species. Benefiting from these synergistic effects, the catalyst achieves current densities of 100 mA cm^-2 at low overpotentials of 259 ± 5 mV, 278 ± 2 mV, and 291 ± 4 mV in alkaline, alkaline simulated seawater, and alkaline natural seawater electrolytes, respectively, while maintaining excellent long-term stability. Furthermore, an anion-exchange membrane water electrolyzer (AEMWE) employing this catalyst as the anode operates stably at 500 mA cm^-2 for 360 h in seawater, demonstrating its promising potential for practical seawater electrolysis. This work establishes a synergistic design paradigm combining electronic modulation and bubble-repellent nanoarchitectures for practical seawater electrolysis.