Rapid synthesis of homogeneous MnO 2/multi-wall carbon nanotubes nanostructure and its electrochemical capacitive behavior

Abstract

A homogeneous composite of MnO 2/multi-wall carbon nanotubes (MnO 2/MWCNTs) was rapidly and efficiently synthesized by a redox reaction of MnO 4 − and Mn 2+ on the MWCNTs under ultrasonic irradiation. The structure and morphology of the obtained MnO 2 and MnO 2/MWCNTs composite were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and transmission electron microscopy. Electrochemical investigation indicated that the maximum specific capacitance of the MnO 2/MWCNTs composite, measured by galvanostatic charge–discharge test, was 315 F g − 1 , compared to the pristine MnO 2 (192 F g − 1 ) and MWCNTs electrode (25 F g − 1 ), showing the synergistic effect of MWCNTs and MnO 2. The homogeneous hybrid nanostructure and the good conductivity of MWCNTs were considered to be responsible for its preferable electrochemical performances.