Interfacial Microenvironment Modulation Enhancing Catalytic Kinetics of Binary Metal Sulfides Heterostructures for Advanced Water Splitting Electrocatalysts

Interfacial microenvironment modulation has been proven to be a promising route to fabricate highly efficient catalysts. In this work, the lattice defect‐rich NiS 2 /MoS 2 nanoflakes (NMS NFs) electrocatalysts are successfully synthesized by a simple strategy. Benefiting from the abundant lattice defects and modulated interfacial microenvironment between NiS 2 and MoS 2 , the prepared NMS NFs show superior catalytic activity for water splitting. Particularly, the optimized NMS NFs (the molar ratio of Ni:Mo = 5:5) exhibit remarkable catalytic activity toward overall water splitting with a voltage of 1.60 V at 10 mA cm −2 in alkaline media, which is lower than that of the noble‐metal‐based electrocatalysts (1.68 V at 10 mA cm −2 ). The NMS NFs electrocatalysts also show exceptional long‐term stability (>50 h) for overall water splitting. The density functional theory results demonstrate that the injection of NiS 2 into MoS 2 can greatly optimize the catalytic kinetics and reduce the energy barrier for hydrogen/oxygen evolution reactions. The work does not only offer a promising candidate for a highly efficient water splitting electrocatalyst but also highlights that interfacial microenvironment modulation is a potential strategy to optimize the catalytic kinetics.