TiO2 Nanobelts/CdSSe Quantum Dots Nanocomposite

This work presents the successful noncovalent attachment of ∼5 nm diameter cadmium−sulfur−selenium (CdSSe) quantum dots on strips of anatase TiO2 nanobelts. The TiO2 nanobelts were hydrothermally synthesized from a strong alkaline solution and subsequently heat-treated to achieve the anatase phase. The self-assembled-monolayer (SAM) technique was employed to attach the quantum dots onto the nanobelts. Due to the hydrophobic nature of the quantum dots, the surface of the nanobelts was first self-assembled with a layer of hydrophobic organic layer before both mixtures were added together. The resulting nanostructure assembly and composition was confirmed via transmission-electron-microscopy (TEM) imaging, Raman spectroscopy, UV−visible absorption spectroscopy (UV−vis), and X-ray photoelectron spectroscopy (XPS). Both Raman and UV−vis spectroscopies indicate evidence of interactions between the quantum dots and nanobelts. The visible-light sensitizing effect of the quantum dots was demonstrated in photocurrent experiments.