Facile synthesis of reduced graphene oxide, titanium (IV) oxide, polythiophene, and carbon black nanocomposites and their supercapacitor applications

Abstract

In this paper, a novel hybrid electrode materials together with graphene oxide or reduced graphene oxide (GO/rGO), titanium dioxide (TiO₂), polythiophene (PTh), and carbon black (CB) were prepared an easy, low cost, and sustainable approach to synthesize GO/TiO₂/PTh and rGO/TiO₂/PTh/CB nanocomposites. In addition, GO/TiO₂/PTh by different weight amount of TiO₂ (0.05, 0.075, 0.1, and 0.125 g) were studied in two-electrode system for supercapacitor device applications. Nanocomposites were characterized by Fourier-transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), scanning electron microscopy-energy-dispersive X-ray (SEM–EDX), atomic force microscopy (AFM) analysis, thermogravimetric-differential thermal analysis (TGA-DTA), Brunauer–Emmett–Teller (BET) analysis, and four-point probe analysis. The highest specific capacitance was achieved as C_sp = 1292.63 F/g for rGO/TiO₂/PTh/CB nanocomposite at 2 mV/s by CV method. The highest electrical conductivity was observed as Ϭ = 2.24 × 10⁻³ S/cm for PTh. PTh increases the electron transfer movement together with TiO₂ and CB nanoparticles. The surface area (58.62 m²/g for rGO) and pore volume of rGO (0.027 cm³/g for rGO) support the better electrochemical performance of rGO/TiO₂/PTh/CB nanocomposite. Moreover, the long-term stability experiments show that the highest initial specific capacitance preservation was obtained as 110% for rGO/TiO₂/PTh/CB nanocomposite at 100 mV/s for 1000 charge–discharge cycles. Moreover, it exhibits high coulombic efficiency. Electrochemical impedance spectroscopic (EIS) results were evaluated to interpret equivalent circuit models of [R_S(C₁(R₁(R₂C₂)))] obtained from ZSimpWin 3.22 simulation programme.