Interfacial Linkages Enhance Redox-Adaptive Bifunctional Catalysis of Heterostructured Catalysts

Abstract

Interfacial electronic communication is critical for electronic structure modulations and thus catalytic activity enhancements of heterostructured water electrolysis catalysts. Here, a bifunctional NiMo/NiFe-LDH heterostructured catalyst, endowed high catalytic activities through positive synergy enhanced by interfacial chemically bonded Mo-O-M linkages, is rationally designed. Uniformly dispersed NiMo nanocrystals anchor on NiFe-LDH nanosheets, forming abundant and robust nanointerfaces that facilitate potential dependent charge redistributions for electronic structure modulations to enhance water electrolysis.NiMo/NiFe-LDH exhibits outstanding overall water electrolysis performances, requiring only 1.476 and 1.72 V to deliver current densities of 10 and 500 mA cm⁻², respectively along with stable operations at an industrially relevant high current density of 500 mA cm -2 . Compared to its single component counterparts, NiMo/NiFe-LDH achieves substantially reduced overpotentials for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) by 56 and 66 mV, respectively, at 500 mA cm⁻², exhibiting strong synergy toward bifunctional catalytic efficiency. X-ray photoelectron spectroscopic analyses confirm interfacial charge redistributions, whereas in-situ X-ray absorption and Raman spectroscopic characterizations under HER and OER conditions reveal potential dependent electronic structure modulations. These findings highlight the critical role of interfacial linkages in promoting bifunctional electrocatalysis and demonstrate practical viability of NiMo/NiFe-LDH for efficient and durable green hydrogen production.