Heterostructures of NiFe LDH hierarchically assembled on MoS2 nanosheets as high-efficiency electrocatalysts for overall water splitting

Typically, rational interfacial engineering can effectively modify the adsorption energy of active hydrogen molecules to improve water splitting efficiency. NiFe layered double hydroxide (NiFe LDH) composite, an efficient oxygen evolution reaction (OER) catalyst, suffers from slow hydrogen evolution reaction (HER) kinetics, restricting its application for overall water splitting. Herein, we construct the hierarchical MoS2/NiFe LDH nanosheets with a heterogeneous interface used for HER and OER. Benefiting the hierarchical heterogeneous interface optimized hydrogen Gibbs free energy, tens of exposed active sites, rapid mass- and charge-transfer processes, the MoS2/NiFe LDH displays a highly efficient synergistic electrocatalytic effect. The MoS2/NiFe LDH electrode in 1 mol/L KOH exhibits excellent HER activity, only 98 mV overpotential at 10 mA/cm2. Significantly, when it assembled as anode and cathode for overall water splitting, only 1.61 V cell voltage was required to achieve 10 mA/cm2 with excellent durability (50 h).