Synthesis of rGO/TiO2/PEDOT nanocomposites, supercapacitor device performances and equivalent electrical circuit models

Abstract

A new nanocomposite electrode incorporating poly(3,4-ethylenedioxythiophene) (PEDOT) within the nanocomposite film of the reduced graphene oxide / Titanium dioxide (TiO2) was synthesized to be used in supercapacitor devices. We used constant EDOT monomer for in-situ polymerization and different initial monomer concentration ratio of [rGO](o)/[TiO2](o)=1/1, 1/2 and 1/5. The obtained nanocomposites were examined by FTIR-ATR, UV-vis, SEM-EDX, TGA-DTA, BET surface areas and pore distribution, XRD, TEM, AFM, CV, GCD and EIS analyses. The results showed that graphene oxide was successfully reduced to rGO by means of the microwave-assisted method. It was confirmed by the increases in the specific capacitance of (C-sp=652F/g) at 1mV/s for the rGO/TiO2/PEDOT nanocomposite at [rGO](o)/[TiO2](o)=1/5. This was related to the pore size (similar to 33.50nm) of the material for rGO/TiO2/PEDOT at [rGO](o)/[TiO2](o)=1/5 obtained from BET analysis. The other C-sp values were 475.33F/g for [rGO](o)/[TiO2](o)=1/2, 114.09F/g for rGO/PEDOT and 48.02F/g for [rGO](o)/[TiO2](o)=1/1. Equivalent circuit model of R-ct(CdlRct) was analyzed via ZSimpWin and TINA programmes. A facile and inexpensive approach for a ternary nanocomposite synthesis of rGO/TiO2/PEDOT was presented for future supercapacitor applications.