Supercapacitive performance of solution processed free standing TiO2-rGO-TiO2 sandwich film electrodes

The development of flexibility and robustness in functional devices is an important feature for the next generation of devices for long operational periods. It infers applications for the compactness of batteries, bio- sensors, supercapacitors, wearable devices, and photovoltaics as well. Here, we report a two-step low-cost solution-based process to synthesize (a) free-standing films of graphene oxide (GO) and reduced graphene oxide (rGO) and (b) hybrid sandwich structures of titania and rGO by using simple chemical bath deposition. The microstructure and morphological study are carried out using X-ray diffraction, atomic force microscopy, and scanning electron microscopy. Its electrochemical performance for supercapacitor electrodes were evaluated using three electrode cyclic voltammetry and galvanostatic charge-discharge system at different current density. In our experiment, graphene oxide is showing pseudo capacitance like behaviour, rGO and TiO2-rGO-TiO2 sandwich structure shows supercapacitor like behaviour. The value of capacitance for rGO is found 57.61 F/g. The sandwich structure with 0.17 M titania layers showing 121.92 F/g at 1.5 A/g current density with the highest power density observed 416 W/kg. Thus, this hybrid approach is not only having the potential to significantly boost the performance of future energy storage technologies but can also be used to develop cost-effective wearable electronics.