Hierarchical NiFe layered double hydroxides: a bifunctional electrocatalyst for overall water splitting

Electrocatalytic hydrogen production from water is limited by sluggish kinetics and requires a highly overpotential of anodic oxygen evolution reaction (OER) and cathodic hydrogen evolution reaction (HER). NiFe double hydroxides (NiFe-LDH) bifunctional group catalyst is applied to OER/HER under alkaline conditions. The good chemical contact between LDH nanosheets grown in situ (NiFe-LDH) on nickel foam (NF) and nickel foam substrate improves the electrons and ions transportation in the reaction process, which is beneficial to promote the OER/HER. The results show only 464.6/219.4 mV overpotential (vs reversible hydrogen electrode (RHE)) at 100/10 mA cm−2for OER/HER, respectively. The stability of D0(stands for NiFe-LDH/NF) was measured at 10 mA cm−2worked continuously for 24 h, and it is found that D0exhibits excellent stable catalytic performance. This work opens up a simple way to design and prepare the efficient, low-cost, and easily synthetic earth-rich electrocatalysts.