LAUSR

Abstract Via a facile one-step chemical bath deposition route, homogeneously dispersed Mn 3 O 4 nanoparticles have been successfully deposited onto the inner surface of TiO 2 nanotube arrays (TNAs). The content and size of Mn 3 O 4 can be controlled by changing the deposition time. Field emission scanning electron microscopy and transmission electron microscopy analysis reveal the morphologies structures of Mn 3 O 4 /TNAs composites. The crystal-line structures are characterized by the X-ray diffraction patterns and Raman spectra. X-ray photoelectron spectroscopy further confirms the valence states of the sample elements. The electrochemical properties of Mn 3 O 4 /TNAs electrodes are systematically investigated by the combine use of cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The resulting Mn 3 O 4 /TNAs electrode prepared by deposition time of 3 h shows the highest specific capacitance of 570 F g −1 at a current density of 1 A g −1 . And it also shows an excellent long-term cycling stability at a current density of 5 A g −1 , which remaining 91.8% of the initial capacitance after 2000 cycles. Thus this kind of Mn 3 O 4 nanoparticles decorated TNAs may be considered as an alternative promising candidate for high performance supercapacitor electrodes.