Using Supercritical Fluids for CdS and CdTeS Nanoparticle Decorated TiO2 Nanostructures

Abstract: TiO2 nanowires were sensitized with CdS and CdTeS quantum dots which were grown using an in situ colloidal method using both conventional organic solvents and supercritical carbon dioxide (scCO2). No pretreatment of the TiO2 nanowires was required prior to nanoparticle generation. The resulting nanostructure assembly and composition was confirmed by transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The electronic structure of TiO2 nanowires was preserved as indicated by Raman spectroscopy. The sensitization of the TiO2 nanowires by the QD's was confirmed by photocurrent measurements.