Abstract:

MnO2 thin film was electrodeposited onto aligned carbon nanotubes (ACNTs) electrode in the electrolyte containing 0.2 mol/L Mn(CH3COO)2 and 0.1mol/L Na2SO4 at pH 6.0. As observed by scanning electron microscopy, the resulting MnO2 film on those nanotubes is hole-like microstructure. Such-prepared MnO2-modified ACNTs nanocomposite was then characterized by cyclic voltammograms, charge-discharge curve and electrochemical impedance measurements etc., and it performed excellent capacitive behavior between 0-0.6v (versus Ag/AgCl) in 1mol/L KCl aqueous solution. The specific capacitance of the ACNT electrode was calculated at 16F/g before the MnO2 film modification, and then it increased to 330 F/g after the MnO2 film deposition due to the special Faradic capacitance of MnO2 With scaning for 200 cycles, there’s a litter change for its cyclic voltammogram curve, indicating the good reversible and capacitive property for the MnO2-ACNTs composite.

Key words: aligned carbon nanotubes; supercapacitor; manganese oxide