High electrochemical selectivity of edge versus terrace sites in two-dimensional layered MoS₂ materials

Exploring the chemical reactivity of different atomic sites on crystal surface and controlling their exposures are important for catalysis and renewable energy storage. Here, we use two-dimensional layered molybdenum disulfide (MoS₂) to demonstrate the electrochemical selectivity of edge versus terrace sites for Li-S batteries and hydrogen evolution reaction (HER). Lithium sulfide (Li₂S) nanoparticles decorates along the edges of the MoS₂ nanosheet versus terrace, confirming the strong binding energies between Li₂S and the edge sites and guiding the improved electrode design for Li-S batteries. We also provided clear comparison of HER activity between edge and terrace sites of MoS₂ beyond the previous theoretical prediction and experimental proof.