Synthesis and electrochemical properties of CeO_2 nanoparticle modified TiO_2 nanotube arrays

摘要

In this paper, a cerium dioxide (CeO_2) modified titanium dioxide (TiO_2) nanotube array film was fabricated by electrodeposition of CeO_2 nanoparticles onto an anodized TiO_2 nanotube array. The structural investigation by X-ray diffraction, scanning electron microscopy and transmission electron microscopy indicated that the CeO_2 nanoparticles grew uniformly on the walls of the TiO_2 nanotubes. The composite was composed of cubic-phase CeO_2 crystallites and anatase-phase TiO_2 after annealing at 450℃. The cyclic voltammetry and chronoamperometric charge/discharge measurement results indicated that the CeO_2 modification obviously increased the charge storage capacity of the TiO_2 nanotubes. The charge transfer process at the surface, that is, the pseudocapacitance, was the dominate mechanism of the charge storage in CeO_2-modified TiO_2 nanotubes. The greater number of surface active sites resulting from uniform application of the CeO_2 nanoparticles to the well-aligned TiO_2 nanotubes contributed to the enhancement of the charge storage density.