Hollow FeCo-FeCoP@C nanocubes embedded in nitrogen-doped carbon nanocages for efficient overall water splitting

Designing readily available and highly active electrocatalysts for water splitting is essential for renewable energy technologies. Here we present the construction of FeCo-FeCoP@C hollow nanocubes encapsulated in nitrogen-doped carbon nanocages (FeCo-FeCoP@C@NCCs) through controlled carbonization and subsequent phosphorization of a Prussian blue analogue. With stronger electronic interaction and hollow structure, the as-obtained FeCo-FeCoP@C@NCCs material requires small overpotentials of 91 mV and 280 mV to deliver 10 mA cm⁻² in 1 M KOH toward hydrogen and oxygen evolution, respectively. More importantly, applying this material for overall water splitting, it only requires 1.64 V to afford 10 mA cm⁻² and exhibits impressively durability over 40 h without obvious performance decay. The present approach inspires potentials for the controllable synthesis of multi-component catalysts for practical applications.