Rapid synthesis of porous Ni/Co/Fe-LDHs nanosheets for effective electrochemical oxygen evolution reaction and zinc-air batteries

Transition metal compounds, especially layered double hydroxide materials (LDHs), show excellent catalytic activity in oxygen evolution reaction (OER). The ethanol oxidation reaction (EOR) is an innovative alternative anodic reaction to OER for improving the efficiency of water splitting to produce hydrogen. In order to improve the reactivity and explore the similarities and differences of active sites in the two reactions, three kinds of porous LDHs (NiFe, NiCo, CoFe LDHs) were synthesized and a series of tests were carried out. Among them, the best performing OER catalyst is NiFe-LDHs with a low overpotential of 1.44 V vs. RHE at 10 mA cm −2 and a Tafel slope of 23.85 mV dec −1 . As for the EOR reaction, NiCo-LDHs is the best, with an overpotential of only 1.38 V vs. RHE at 10 mA cm −2 and a Tafel slope of 71.58 mV dec-1. In addition, compared with OER, the LHDs material exhibited better stability in the EOR. This work provides a new direction for studying the electrocatalytic activity of LDHs materials in OER and EOR. • Three LDHs were successfully prepared in 10 min by a rapid synthesis method. • NiFe-LDHs with more Ni 3+ have the smallest Tafel slope in both OER and EOR. • NiCo-LDHs have the lowest overpotential in EOR due to the synergy between metals. • High efficiency and favorable stability make it possible for further application.