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

摘要

Ultrathin WS _(2) nanosheets are vertically embedded in hollow mesoporous carbon spheres (HMCSs) to form unique hierarchical triple-shell (WS _(2) –C–WS _(2) ) hollow nanospheres, i.e. HTSHNs WS _(2) /C, via a facile and scalable hydrothermal method. The as-synthesized HTSHNs WS _(2) /C nanocomposites are confirmed to have an expanded interlayer spacing of WS _(2) with chemical bonding between WS _(2) and HMCSs. The expanded WS _(2) interlayer spacing contributes to the enhancement of the kinetics of ion/electron transport and the improvement of the electrochemical performance of the HTSHNs WS _(2) /C. As a result, the optimized HTSHNs WS _(2) /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 WS _(2) /C provide abundant catalytically active sites for the enhancement of the electrocatalytic activity for the hydrogen evolution reaction (HER).