Boosted electrochemical performance of TiO₂ decorated RGO/CNT hybrid nanocomposite by UV irradiation

Abstract

Titania decorated RGO/CNT hybrid electrode material was prepared for supercapacitor (SCs) application through facile hydrothermal approach. Combined act of 1D CNTs and 2D RGO assists the uniform in-situ growth of titania towards high surface area mesoporous self-assembled interconnected morphology which is confirmed from FESEM and BET surface area analysis. This interconnected porous network like structure can efficiently allow the better mass transport and decreased contact resistance towards high electrochemical utilization. Electrochemical measurements revealed the superior performance of hybrid nanocomposite comprising of titania/RGO/CNT (TG₁C₁) which exhibited maximum specific capacitance around 477 F/g at current density 1 A/g. However, this capacitance value was further enhanced up to 537 F/g after 1 hour of UV light irradiation. This enhancement could be ascribed to photo-catalytic effect of TiO₂ and corresponding genesis of photo-excited electrons on TiO₂ surface which further channelized through interconnected RGO and CNT morphology and hence results in improved specific capacitance. These observations were in good agreement with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis. The hybrid nanocomposite also showed satisfying energy density and power density. It was also found that prepared hybrid nanocomposites were stable up to 2000 cycles with maximum specific capacitance retention of 92% of initial value.