In situ prepared amorphous FeCoO-Polyaniline/multiwalled carbon nanotube nanohybrids as efficient oxygen evolution catalysts for rechargeable Zn-air batteries

Efficient catalyst with low overpotential and small Tafel slope for oxygen evolution reaction is the key factor to improve overall efficiency of Zn-air battery. In the present study, a novel hybrid catalyst with polyaniline and amorphous iron-cobalt-binary oxide supporting on multiwalled carbon nanotubes is prepared via a simple in situ method by mixing Fe+, Co2+, aniline and multiwalled carbon nanotubes together followed by subsequent borohydride reduction with citrate as protective stabilizer. The optimal sample exhibits remarkable activity for oxygen evolution reaction in 0.1 M KOH solution, accompanied by a low overpotential of 440 mV at a current density of 10 mA cm(-2), and a small Tafel slope of 55 mV dec(-1). Such catalyst can endow rechargeable Zn-air battery with a high peak power density of 287.4 mW cm(-2) and long-term cycling performance over 100 h with high efficiency and stability, demonstrating its promising feasibility as highly active electrocatalyst for rechargeable metal-air batteries.