Few-layered MoSe₂ nanosheets as an advanced electrode material for supercapacitors

We report the synthesis of few-layered MoSe₂ nanosheets using a facile hydrothermal method and their electrochemical charge storage behavior. A systematic study of the structure and morphology of the as-synthesized MoSe₂ nanosheets was performed. The downward peak shift in the Raman spectrum and the high-resolution transmission electron microscopy images confirmed the formation of few-layered nanosheets. The electrochemical energy-storage behavior of MoSe₂ nanosheets was also investigated for supercapacitor applications in a symmetric cell configuration. The MoSe₂ nanosheet electrode exhibited a maximum specific capacitance of 198.9 F g^-1 and the symmetric device showed 49.7 F g^-1 at a scan rate of 2 mV s^-1. A capacitance retention of approximately 75% was observed even after 10 000 cycles at a high charge-discharge current density of 5 A g^-1. The two-dimensional MoSe₂ nanosheets exhibited a high specific capacitance and good cyclic stability, which makes it a promising electrode material for supercapacitor applications.