Ultrathin WS2 nanosheets vertically embedded in a hollow mesoporous carbon framework – a triple-shell structure with enhanced lithium storage and electrocatalytic properties

Abstract

Ultrathin WS₂ nanosheets are vertically embedded in hollow mesoporous carbon spheres (HMCSs) to form unique hierarchical triple-shell (WS₂–C–WS₂) hollow nanospheres, i.e. HTSHNs WS₂/C, via a facile and scalable hydrothermal method. The as-synthesized HTSHNs WS₂/C nanocomposites are confirmed to have an expanded interlayer spacing of WS₂ with chemical bonding between WS₂ and HMCSs. The expanded WS₂ interlayer spacing contributes to the enhancement of the kinetics of ion/electron transport and the improvement of the electrochemical performance of the HTSHNs WS₂/C. As a result, the optimized HTSHNs WS₂/C composites deliver a superior rate capability of 396 mA h g⁻¹ at 10 A g⁻¹, and stable cycling performance up to 1000 cycles, presenting a capacity of 784 and 442 mA h g⁻¹ at 1 and 5 A g⁻¹, respectively. Additionally, HTSHNs WS₂/C provide abundant catalytically active sites for the enhancement of the electrocatalytic activity for the hydrogen evolution reaction (HER).