Heterojunction Engineering of CdS and Ag2S Quantum Dots Co-Sensitized TiO2 Nanotube Array Photoelectrode

CdS and Ag2S heteojunctions sensitized TiO2 nanotube arrays (TiO2 NTs/CdS-Ag2S) were prepared by cation exchange between Cd2+ and Ag+ on the basis of the TiO2 NTs/CdS. The deposition of CdS and Ag2S heteojunctions on the upper and inner surface of the TiO2 NTs was confirmed by field emission scanning electron (FE-SEM) and transmission electron microscopes (TEM). The UV-vis spectrum of the TiO2 NTs/CdS-Ag2S revealed the photoresponse range covering the full visible and near-infrared regions, and showed considerable enhanced photoelectrochemical properties. The corresponding charge transfer path of the TiO2 NTs/CdS-Ag2S photoelectrode was also illuminated. (C) 2014 The Electrochemical Society. All rights reserved.