Improved electrochemical performance of rGO/TiO2 nanosheet composite based electrode for supercapacitor applications

Abstract

The present work reports the synthesis of a composite of TiO2 nanosheets (NS) with reduced graphene oxide (rGO) for supercapacitor applications. The formation of composite has been achieved via a simple one-pot hydrothermal method. The rGO/TiO2 NS composite was used to fabricate a flexible electrode which, in presence of 1 M H2SO4 as an electrolyte, has shown a high specific capacitance of 233.67 F/g at a current density of 1 A/g within a potential window of 0–1 V. This enhanced supercapacitance of the rGO/TiO2 NS electrode is attributed to the synergistic effects from TiO2 and rGO NS which help in to attain a low equivalent series resistance and enhanced ion diffusion. Furthermore, the fabricated composite electrode has displayed a long-term cyclic stability, retaining a specific capacitance of 98.2% even after 2000 charge–discharge cycles. The proposed rGO/TiO2 NS electrode has delivered high values of energy (32.454 Wh/kg) and power (716.779 W/kg) densities. Interestingly, it is possible to retrieve a sufficiently high energy density of 24.576 Wh/kg which could generate a power density value of as high as 2142.84 W/kg. The above results reveal that the herein proposed thin film composite of rGO/TiO2 NS can offer extraordinary performance as a supercapacitor electrode compared to its nanotubes or nanoparticles.