Structural, morphological and electrochemical properties of long alkoxy-functionalized polythiophene and TiO2 nanocomposites

Abstract

High performance alkoxy-functionalized polythiophene (PM4EOT) and TiO2 nanocomposites were prepared via a facile in situ oxidative chemical polymerization of thiophene monomer. The morphology studied demonstrated that nanocomposites were of the core–shell structure with a particle size of approximately 30 nm and PM4EOT shell was of about 2–10 nm thickness. X-ray photoelectron spectroscopy (XPS) spectra proved that there was a new Ti–S interaction between the polymer and TiO2 surface. The supercapacitive behaviors of the nanocomposites investigated by cyclic voltammetry galvanostatic charge–discharge and AC impedance measurements demonstrated that the prepared PM4EOT/TiO2 nanocomposite [1:1 (weight ratio)] exhibits enhanced specific capacitance and cycling stability as compared to the two pristine components and various ratio contents. The specific capacitance of PM4EOT/TiO2 nanocomposite (1:1) was obtained up to 111 F/g at a current density of 0.5 A/g, which is much higher than that of the pure PM4EOT (45 F/g) and TiO2 (1.6 F/g). In addition, the energy density of 15.4 Wh kg−1 and the power density of 308 W kg−1 delivered by composite (1:1) capacitor were achieved at a current density of 0.5 A/g.