Multi-structure modulation in Ni-based oxidation enables high water catalysis

The main challenges of alkaline overall water splitting stem from the "scarcity of efficient catalysts" and the "inherent hysteresis in reaction kinetics" of both the HER and OER in alkaline environments. A promising strategy to address these challenges is the construction of a composite catalyst structure that can independently optimize multiple active sites, thereby accelerating multi-step electron transfer during the water splitting process. In this study, Ni-based nano-composite catalytic materials (NiFeMoO _x ) with adjustable surface compositions were synthesized via co-precipitation combined with low-temperature annealing. The incorporation of Ni enhances the conductivity of the catalyst by promoting rapid electron migration, while the composite phase structure creates multiple active sites, optimizing the reaction energy barrier and improving electrocatalytic performance. In the OER performance test, the catalyst exhibits an overpotential of 297 mV at 50 mA cm ^-2 and a Tafel slope of 67.0 mV dec ^-1 . In the HER performance test, the overpotential is 183 mV at 10 mA cm ^-2 , with a Tafel slope of 193.6 mV dec ^-1 . This work presents a new approach for designing efficient bifunctional heterogeneous electrocatalysts for overall water splitting.