Interfacial engineering for promoting charge transfer in MoS2/CoFeLDH heterostructure electrodes for overall water splitting

Abstract

In order to enhance the kinetics of water electrolysis and reduce the cell voltage, the development of highly active and stable non-precious metal bifunctional catalysts is essential. In this study, self-supported heterostructures based on MoS2-CoFeLDH were synthesised as the cathode and anode electrocatalysts for overall water splitting in alkaline media. The strong coupling effect at the heterogeneous interfaces of MoS2 and CoFeLDH improved the hydrogen evolution reaction (HER) at the cathode. The strong electronegativity of CoFeLDH facilitated the adsorption of H protons, and MoS2 with strong electrical conductivity promoted the desorption of H2 molecules. The oxygen evolution reaction (OER) at the anode was also enhanced because the LDHs had strong adsorption properties for hydroxyl species, and MoS2 assisted the transfer of hydroxyl species. The MoS2-CoFeLDH showed low overpotentials of 100 mV for the HER and 216 mV for the OER at 10 mA/cm2. This bifunctional catalyst required a low voltage of 1.55 V for overall water splitting and remained stable for 48 h.