Electro-Optics and Band Gap Energies of Nanosilver-Coated TiO2 Nanotubes on Titanium Metal

Abstract

TiO2 nanotubes on Ti metal surface were prepared by the electrochemical anodization method. Then, nanosilver was deposited onto the nanotubes by the electroless dip coating and the anodization. The obtained TiO2 nanotubes were examined by using scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, cyclic voltammetry, and UV-Vis. The electrochemical band gap (E-g(CV)) of the nanosilver-coated TiO2 nanotubes prepared by the anodization was found as 1.54 eV. Using the UV-Vis measurements, the optical band gap energy (E-g(op).) was calculated as 1.51 eV for the Ag/TiO2 nanotubes obtained by electroless dip coating. The electrical conductivity of the TiO2 nanotubes also increased from 3.0 x 10(-4) to 34.7 S/cm after nano Ag deposition by the anodization method. These Ag/TiO2 nanotubes with low band gap and high electrical conductivity are desirable for the applications in electronics, Li-ion batteries, and solar cells.