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

Abstract

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 synthesized 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 performance, 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-sensitized 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%).