We report on a colloidal synthesis of Pbse/TiO2 heterostructures, comprising small-diameter PbSe nanocrystals epitaxially grown onto the surface of TiO2 nanorods. The deposition of lead selenide onto prefabricated TiO2 nanocrystals proceeds via formation of a thin PbSe shell that subsequently breaks into sub-2-nm islands. Additional precursor injections are then used to increase the size of PbSe nanocrystals up to 5 nm. In the case of small-size PbSe, a 2.1-ns transfer of photoinduced carriers into TiO2 domain was evidenced through quenching of the PbSe band gap emission. Overall, the present synthesis demonstrates a colloidal approach to all-inorganic modification of TiO2 surfaces with semiconductor nanocrystals, which provides a viable alternative to a more common supramolecular assembly of nanocrystal-oxide composites.
Acharya, Krishna P.; Alabi, Taiwo R.; Schmall, Nicholas; Hewa-Kasakarage, Nishshanka N.; Kirsanova, Maria; Nemchinov, Alexander; Khon, Elena; and Zamkov, Mikhail, "Linker-Free Modification Of TiO2 Nanorods With PbSe Nanocrystals" (2009). Physics and Astronomy Faculty Publications. 9.
Journal Of Physical Chemistry C