In-situ construction defect-rich CuNiCoS4 /1T-MoS2 heterostructures as superior electrocatalysts for water splitting

Rational design and construction of bifunctional heterostructure electrocatalysts with high-conductivity and more active sites is imperative for water splitting. Herein, based on the tunable property of layered double hydroxide laminates cations, topological transformation technology and template confine method, a series of high-performance bifunctional catalysts composed of transition metal doping NiCo2S4 (MNiCoS4, M = Cu, Fe, Zn, Mn) and 1T-MoS2 were in-situ fabricated on nickel foam. In particular, CuNiCoS4/1T-MoS2 exhibits an ultralow overpotential of 163 mV at 50 mA cm-2 for oxygen evolution reaction (OER) and favorable hydrogen evolution reaction activity. The two-electrode system requires only 1.52 V to attain a current density of 10 mA cm-2. To the best of our knowledge, its OER electrocatalytic activity far exceed state-of-art catalysts reported. The outstanding performance of this series of catalysts can be attributed to two aspects. First, the highly conductive 1T-MoS2 can facilitate electron transfer, and second, the defect-rich heterostructure can effectively regulate the electronic structure of the active metal and expose abundant active sites. This work provides a valuable strategy for developing high activity electrocatalysts for efficient water splitting.