The effect of sandwiched Ag in the wall of TiO2 nanotube on the photo-catalytic performance

TiO2 nanotube was synthesized by a hydrothermal process using TiO2 nanoparticle as starting material, and then it was loaded with Ag through a silver mirror reaction. Further, the Ag loading TiO2 nanotube was decorated by TiO2 via TiCl4 hydrolysis to obtain the TiO2 nanotube with the wall sandwiched by Ag. The TiO2 nanotubes were characterized by transmission electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction and UV-vis spectrophotometer. The electrochemical impedance spectroscopy and transient photocurrent were investigated in a three-electrode system with the TiO2 nanotube films served as photoanodes. The photo-catalytic activity was evaluated by photo-degradation of methyl orange under UV light irradiation. The results show that the sandwiched Ag could inhibit the crystal phase transformation of TiO2 nanotube from anatase to rutile. And the sandwiched nanotube structure exhibits enhanced photo-catalytic performance due to the efficient separation of the photo-generated carriers. (C) 2011 Elsevier B.V. All rights reserved.