In-situ generating highly efficient sites for multifunctional water splitting/Zn-air battery over hierarchically architectured Fe2Ni3 nanoalloy/N-incorporated carbon matrix

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 Fe 2 Ni 3 nanoalloys/N‑incorporated flower-like carbon matrix (Fe 2 Ni 3 -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 ƞ 10  = 280 mV (oxygen evolution), ƞ 10  = 144 mV (hydrogen evolution), and E 1/2  = 0.84 V vs RHE (oxygen reduction) can be accomplished over Fe 2 Ni 3 -NFCM. 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, the structure-performance correlation has been elucidated and the active species/sites identified through the advanced characterizations and detailed comparison investigations.