Boosted Oxygen Evolution Reactivity via Atomic Iron Doping in Cobalt Carbonate Hydroxide Hydrate

Cobalt carbonate hydroxide hydrate (CCHH) has long been functioning merely as a precursor to prepare compound catalysts; however, its intrinsic potential for the oxygen evolution reaction (OER) is quite limited due to its poor catalytic activity. Herein, a concept has been proposed to solve this issue by doping Fe into CCHH nanowires grown on nickel foam (denoted as Fe-CCHH/NF) for achieving efficient OER catalysis by electrochemical transformation. The obtained Fe-CCHH/NF-30 exhibits OER catalytic performance with an overpotential of only 200 mV versus the reversible hydrogen electrode (vs. RHE) at a current density of 10 mA cm^-2 and small Tafel slope of 50 mV dec^-1 in 1 M KOH. Moreover, it displays stability for over 130 h at a large current density of 55 mA cm^-2, and no activity decline is observed after the 3000 cycle test. The performance of Fe-CCHH/NF-30 renders it one of the most promising OER catalysts. The density functional theory calculation reveals that the doped Fe can greatly enhance the OER activity by lowering the reactive energy barrier.