Fabrication of binder-free polyaniline grafted multiwalled carbon nanotube/TiO2 nanotubes/Ti as a novel energy storage electrode for supercapacitor applications

Abstract

Binder-free PANi-g-MWCNT/TiO2NTs/Ti electrodes were successfully fabricated by the electrodeposition of aniline-functionalized multiwalled carbon nanotubes (An-fMWCNT) onto TiO2 nanotubes/Ti and followed by grafting polyaniline chains through in situ chemical polymerization of aniline on the sites of An-fMWCNT. The prepared samples were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. SEM and TEM images revealed that a thin film of polyaniline (PANi) nanoparticles has been uniformly grafted on the surface of the MWCNTs. In the electrode, MWCNTs with good electrical conductivity and mechanical strength constitute a high-efficient conductive network to improve the capacitive behavior and cyclic durability of PANi. The storage energy performance was investigated by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques in 1.0M H2SO4 aqueous solution. The PANi-g-MWCNT/TiO2NTs/Ti electrodes exhibit a high specific capacitance up to 708Fg−1 at 5Ag−1 in 1M H2SO4 and a long cyclic durability with 88% capacitance retention over 1000 cycling, indicating a potential application in the electrode material of supercapacitors.