Enhanced photoelectrochemical properties of TiO2 nanotubes co-sensitized with US nanoparticles and tetrasulfonated copper phthalocyanine

TiO2 nanotubes (TiNTs) with high specific surface area were prepared in a hydrothermal process. The XRD analysis indicated that the TiNTs calcined at 300 degrees C were mainly composed of anatase TiO2. The TiNTs co-sensitized with US nanoparticles and tetrasulfonated copper phthalocyanine (TiNTs/CdS-CuTsPc) were prepared via an in situ formation of US nanoparticles followed by adsorption of CuTsPc molecules. The co-sensitized TiNTs showed better photoresponse from ultraviolet to the near infrared. The results of photoelectrochemical measurements demonstrated that the co-sensitized TiNTs electrode (FrO/TiNTs/CdS-CuTsPc) possessed higher short circuit current J(SC) and IPCE values than those of single-sensitized electrodes, as well as its counterpart fabricated with copper phthalocyanine (FTO/TiNTs/CdS-CuPc). The excellent light-harvesting and efficient spatial separation of the photogenerated charges were considered to be the main reasons responsible for the enhanced photoelectrochemical performance of TiNTs. (C) 2009 Elsevier B.V. All rights reserved.