Edge-Terminated MoS2 Nanosheets with an Expanded Interlayer Spacing on Graphene to Boost Supercapacitive Performance

Abstract 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 (002) 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.