Nanosheet-assembled MoSe₂ and S-doped MoSe_2-x nanostructures for superior lithium storage properties and hydrogen evolution reactions

The development of layered molybdenum chalcogenides with largely exposed active sites is receiving intense interest because of their potential applications in energy storage and catalysis. Here, we report a strategy for the synthesis of hierarchical MoSe₂ and S-doped MoSe_2-x nanostructures resulting from the assembly of nanosheets. The incorporation of S exposes a large quantity of the active edge sites as well as abundant unsaturated sites. For example, the hierarchical S-doped MoSe_2-x nanotubes show a high reversible capacity and excellent cycling performance as an anode material for lithium-ion batteries (LIB). In addition, the synthesized S-doped MoSe_2-x nanosheets exhibit excellent catalytic activity and superior stability for the hydrogen evolution reaction (HER) in acidic medium. The excellent performance of S-doped MoSe_2-x nanosheets has been attributed to the synergistic effect of the high density of active sites as well as the enhanced conductivity.