Edge-terminated MoS₂ nanosheets with an expanded interlayer spacing on graphene to boost supercapacitive performance

The supercapacitive performance of two-dimensional (2D) MoS₂ nanomaterials strongly depends on the interlayer spacing and edge orientation, which remains a formidable challenge. Herein, we demonstrate a sheet-on-sheet 2D heterostructure with edge-terminated and interlayer-expanded MoS₂ few-layered nanosheets on graphene. The preferential (0 0 2) edge orientation with an expanded interlayer spacing of 0.98 nm enables easy insertion of ions into the MoS₂ nanosheets. The intimate connection with conductive graphene further expedites the electrochemical kinetics by promoting electron/ion transport and structural stability. As a result, the MoS₂@graphene nanoarchitecture can deliver a high specific capacitance of 428 F g⁻¹ at 1 A g⁻¹ along with superior rate and long-term durability, which is among the best performance reported so far. The present work highlights the importance of engineering edge-oriented and interlayer-expanded 2D materials for their promising use toward high-performance supercapacitors.