An Investigation into the Influence of Graphene Content on Achieving a High‐Performance TiO2‐Graphene Nanocomposite Supercapacitor

Abstract This study presents the synthesis of TiO2‐graphene nanocomposites with varying mass ratios of graphene (2.5, 5, 10, 20 wt. %) using a facile and cost‐effective hydrothermal approach. By integrating TiO2 nanoparticles with graphene, a nanomaterial characterized by a two‐dimensional structure, unique electrical conductivity and high specific surface area, the resulting hybrid material shows promise for application in supercapacitors. The nanocomposite specimens were characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman microscopy, field‐emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Additionally, supercapacitive properties were investigated using a three‐electrode setup by cyclic voltammetry (CV), galvanostatic charge‐discharge (GCD) and electrochemical impedance spectroscopy (EIS) tests. Notably, the TiO2‐20 wt. % rGO nanocomposite exhibited the highest specific capacitance of 624 F/g at 2 A/g, showcasing superior electrochemical performance. This specimen indicated a high rate capability and cyclic stability (93 % retention after 2000 cycles). Its remarkable energy density and power density of this sample designate it as a strong contender for practical supercapacitor applications.