Co9S8-Ni3S2@CoFe LDH/NF Heterostructure as an Efficient Electrocatalyst for Enhanced Oxygen Evolution Performance.

Exploring efficient, stable, and earth-abundant electrocatalysts toward the oxygen evolution reaction (OER) is a central theme for realizing industrial application of water splitting. In this study, a 1D@2D heterostructure of Co9S8-Ni3S2@CoFe LDH/NF is constructed via hydrothermal and electrodeposition approaches, where ultrathin CoFe LDH nanosheets are interconnected and deposited onto Co9S8-Ni3S2 nanorod arrays. This 1D@2D microstructure benefits from the exposure of a large number of accessible reactive sites. The strong interaction between the sulfide hybrid and LDH material could modulate the electronic structure of Co9S8-Ni3S2@CoFe LDH and generate a high concentration of high-valence metal sites. As a result, the optimal catalyst exhibits superior OER performance with a low overpotential of 189 mV at 10 mA cm-2, a small Tafel slope of 30.22 mV dec-1, and good stability in alkaline solution. This work opens up a possibility for obtaining efficient and cost-effective electrocatalysts for clean energy production through water splitting.