Design bifunctional vanadium carbide embedded in mesoporous carbon electrode for supercapacitor and dye-sensitized solar cell

Vanadium carbide embedded in mesoporous carbon (VC-MC) is prepared using an in-situ synthesis method as hybrid electrode for supercapacitor. The electrochemical performance of the VC and VC-MC electrodes are analyzed and compared through a combination of cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy measurements in 1 M H2SO4 aqueous electrolyte. The introduced mesoporous structure of the hybrid electrode provides optimized conducting pathways for electrons and protons, thus improving the capacitive performance of VC-MC electrode compared to pristine VC electrode. The syn-thesized VC-MC electrode achieves a specific capacitance up to 191.2 F g(-1), which is significantly higher than the pristine VC electrode (95.6 F g(-1)). Moreover, the VC-MC hybrid electrode exhibits an excellent cycle performance with 89.5% capacitance retention after 10,000 charge-discharge cycles, considerably higher than the pristine VC electrode. Apparently, the VC-MC hybrid electrode which shows desirable capacitive perfor-mance, excellent stability and enhanced electrochemical properties can be attributable to the combination of the advantages possessed by MC and VC. Moreover, VC-MC was applied as counter electrode in flexible dye-sen-sitized solar cell which generate power conversion efficiencies of 6.50%, much higher than those of the devices using VC and MC counter electrodes (4.14% and 5.28%).