Two–dimensional (2D) transition metal dichalcogenide materials attracts a huge of attention for application in energy storage devices due to its unique nanostructure and electronic properties. In this study, molybdenum disulfide (MoS2) nanoflowers consisting of 1T-2H hybridized phases have been synthesized using a microwave-assisted hydrothermal method under various conditions. The obtained materials were characterized for the material properties and then made into electrodes for use in supercapacitor. The resulting supercapacitor was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and a charge-discharge technique. The CV measurement shows that as-synthesized MoS2 electrode delivers a capacitance as high as 262 Fg-1 at a scan rate of 5 mV/s in KCl aqueous electrolyte. MoS2 electrode also exhibits excellent electrochemical performance of high conductivity based on the EIS analysis. More importantly, the obtained MoS2 nanoflowers contain the desirable metallic 1T phase. We have therefore proposed a mechanism to explain the formation of the 1T phase. Further enhancement of the electrochemical performance has been achieved through the growth of polypyrrole (PPy) on the MoS2 nanoflowers by in situ polymerization of pyrrole monomers. The PPy provides addition capacitance and conductivity to the MoS2 while the MoS2 prevents PPy from degradation, thus forming MoS2/PPy nanocomposites that exhibit extremely high energy densities up to 126 W h kg-1 and excellent cycling stability and making themselves promising candidate electrodes for use in supercapacitors. The effects of materials characteristics on the electrochemical performance is also addressed.

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