MO x /Rh Metallene with Energetic Interfaces as Efficient Bifunctional Electrocatalyst for Durable Water Splitting

Developing excellent activity and stability bifunctional electrocatalysts for alkaline water splitting remains challenging. This work constructs ultrathin MO_x/Rh metallene heterostructures (M = Fe, Co, Ni) via atmosphere-controlled solvothermal synthesis, achieving uniform MO_x nanoclusters on Rh metallene with optimized interfaces. The FeO_x/Rh catalyst demonstrates exceptional bifunctional activity, requiring only 1.53 V for overall water splitting at 10 mA cm^-2 with robust durability. Leveraging the unique oxygen-affinity of FeO_x and its strong electronic coupling with Rh, this study reveals the critical role of the high-energy interface in accelerating the kinetics of the rate-limiting four-electron oxygen evolution reaction. Mechanistic insights reveal that FeO_x promotes water dissociation via optimized orbital hybridization, while electronically modulated Rh optimizes hydrogen adsorption (ΔG_H* = -0.057 eV) via d-band downshifting. This interfacial engineering strategy enables efficient solar-driven hydrogen production, offering a sophisticated paradigm for designing high-performance bifunctional metallene catalysts.