The Photocatalytic Properties and Mechanistic Study of ZnO,Ag Multiphase Co-Composited TiO 2 Nanotube Arrays Film Prepared by One-Step Anodization Method

Abstract

© 2018 The Electrochemical Society. ZnO/Ag multi-phase composited TiO2 nanotube arrays (TiO2 TNAs) films were prepared on pure Ti substrate through one-step anodizing method using double pulse plating power supply. The deposition amount of Ag and ZnO were adjusted by changing the concentration of Zn(NO3)2 - 6H2O and AgNO3 and reverse voltage. The results showed that ZnO deposited in the wall of TiO2 NTAs dispersedly; sedimentary phase and dispersed phase are the two forms of deposited Ag in TiO2 NTAs. The bandgap narrowed 0.33 eV, and the recombination rate of photo-generated electron-hole pairs also decreased obviously due to the doping energy level synergistic effect of ZnO and the Surface Plasmon Resonance (SPR) effect of Ag. Furthermore, the sample with 1 mMZnO+0.4 mM Ag and 5 V reverse voltage has the best photocatalytic properties, the degradation rate of Methylene blue (MB) reached 86% which improved 15% compared with undoped TiO2 NTAs.