Hierarchical Architecture of Fe2ni3 Nanoalloys/Nitrogen-Incorprated Flower-Like Carbon Matrix Exceptional for Multifunctional Water Splitting and Zn-Air Battery

A multifunctional electrocatalyst for water splitting and zinc-air battery involves totally three reactions, namely, oxygen reduction, oxygen evolution, and hydrogen evolution, and is very demanding and challenging. The current study provided an interesting example to achieve such a goal by establishing hierarchical architecture of Fe2Ni3 nanoalloys/N-incorporated flower-like carbon matrix (Fe2Ni3-NFCM). The resulting material is free of noble metals and can simultaneously promote the three reactions with excellent activity and robust durability. Significantly, the outstanding parameters ƞ10 = 280 mV (oxygen evolution), ƞ10 = 144 mV (hydrogen evolution), and E1/2 = 0.82 V vs. RHE (oxygen reduction) can be accomplished over the same material. Moreover, a voltage as low as 1.50 V (10 mA cm−2) and a 76-h durability for water-splitting has been achieved. The assembled Zn-air battery employing the current material as the electrodes can provide the power density being ~122 mW cm−2 plus robust cyclic durability. The multifunctional performance reaches the top level among the various counterparts and its structure-performance correlation has been elucidated through the systematic physicochemical characterizations