Integrating Multiple Catalytic Active Sites into One Composite System for Highly Efficient and Durable Water Oxidation

Developing an active, affordable, and stable catalyst for efficient oxygen evolution during water electrolysis remains a formidable task in contemporary research. The sluggish kinetics of the oxygen evolution reaction (OER) continues to impede the overall efficiency of the electrolysis process. A comprehensive approach is demonstrated here to develop multiple catalytic active components into a single system by means of integrating a bimetallic hydroxide (NiFe(OH)_x) with an amorphous molybdenum sulfide (MoS_x) heterostructure using rational strategies. This proposed fabrication strategy enables the catalytic activity to be enhanced and fast electron transfer, resulting in an OER in strong alkaline media through synergistic effects and effective modulation of electronic interactions. Moreover, the resulting composite electrode (MoS_x/NiFe(OH)_x/NF) displayed the lowest overpotential and a Tafel slope of 298 mV at 50 mA cm^-2 and 47.25 mV dec^-1, respectively, as well as a good stability under large currents over a prolonged period of 48 h without degradation. The demonstrated electrode is found to dynamically reform the surface layer’s active phase after catalyzing the reactions to serve as an effective electrode for water oxidation. These results have not only led to the development of a robust and effective electrocatalyst but also opened up several possibilities for developing multicomponent electrocatalytic systems in one material that can be integrated into conventional catalyst designs.