Metallic 1T Phase\nMoS<sub>2</sub> Nanosheets Covalently\nFunctionalized with BBD Molecules for Enhanced Supercapacitor Performances

Metallic 1T phase molybdenum disulfide (MoS<sub>2</sub>) is among\nthe most promising electrode materials for supercapacitors, but its\ncapacitance and cyclability remain to be improved to meet the constantly\nincreasing energy storage needs in portable electronics. In this study,\nwe present a strategy, covalent functionalization, which achieves\nthe improvement of capacitance of metallic 1T phase MoS<sub>2</sub>. Covalently functionalized by the modifier 4-bromobenzenediazonium\ntetrafluoroborate, the metallic MoS<sub>2</sub> membrane exhibits\nincreased interlayer spacing, slightly curled layered architecture,\nenhanced charge transfer, and improved adsorption capabilities toward\nelectrolyte molecules and ions. Thanks to these boosted properties,\nthe functionalized metallic MoS<sub>2</sub> membrane exhibited excellent\nsupercapacitor performances in a 0.5 M TBABF<sub>4</sub> (acetonitrile\nas the solvent) electrolyte (with a specific capacitance of 135.67\nF/cm<sup>3</sup> at 1 A/g, more than three times that of the unfunctionalized\nmetallic MoS<sub>2</sub> membrane) and good stability, which can maintain\na capacitance retention of 76.0% after 10 000 charge–discharge\ncycles.