Fabrication of PbS quantum dot doped TiO2 nanotubes.

PbS quantum dots (PbS QDs) were prepared on the inside and outside surfaces of TiO(2) nanotubes by using thiolactic acid as an organic linker. The sizes of PbS QDs were controlled by employing a dip coating process to anchor the PbS QDs onto the TiO(2) nanotubes. The PbS QDs with diameters of 2-10 nm were obtained by adjusting the concentration of thiolactic acid. TiO(2) nanotubes with PbS QDs located only inside the nanotubes were prepared by first coating the tubes with the double-chain cationic surfactant DDAB. The PbS QDs supported on TiO(2) nanotubes were characterized by TEM, as well as Raman, FT-IR, and UV-vis spectroscopy.