A unique nanocomposite with FeCo nanoalloy anchored on S, N co-doped carbonaceous matrix for high bifunctional oxygen reduction reaction/oxygen evolution reaction electrocatalytic property in Zn-air battery.

A unique nanocomposite of FeCo-NSCC (means FeCo nanoalloy anchored on N, S co-doped carbonaceous composite) is obtained by one-pot pyrolysis using mixed natural wool fibers, dicyandiamide and the corresponding metal salts. The FeCo-NSCC has a higher degree of graphitization and a high specific surface area of 359 m g. The FeCo-NSCC exhibits a promising bifunctional oxygen reduction reaction/oxygen evolution reaction (OER/ORR) electrocatalytic activity with onset potential and half-wave potentials of 0.980 and 0.853 V vs reversible hydrogen electrode for ORR, and a low overpotential of 351 mV at 10 mA cm for OER, superior to that of state-of-the-art commercial Pt/C and RuO. The FeCo-NSCC presents a vigorous bifunctional OER/ORR electrocatalytic activities with the low ΔE(E - E) of 0.727 V, superior to most of the reported non-noble metal-based catalysts. Besides, the FeCo-NSCC shows remarkable durability and methanol resistance. The FeCo-NSCC based battery works at an open circuit voltage of 1.52 V and has a maximum power density of 161 mW cm at current density of 246 mA cm, better than those of Pt/C-RuO based battery (1.47 V; 106 mW cm, 145 mA cm). The FeCo-NSCC based battery is stable with no obvious increased voltage gap after 60 h cycles.