Bi2O3/TiO2 coaxial nanorods: Synthesis, characterization and photoluminescence properties

Abstract Bi2O3-core/TiO2-shell nanorods were prepared by the thermal evaporation of Bi2O3 and the metal organic chemical vapor deposition of TiO2. The Bi2O3-core is a pure simple monoclinic α-Bi2O3 phase single crystal, whereas the TiO2 shell has a simple tetragonal structure. The PL emission intensity of the Bi2O3 nanorods was enhanced by the TiO2 coating. The optimal TiO2 coating layer thickness for the highest emission intensity was 60 nm. On the other hand, the PL properties of the Bi2O3-core/TiO2-shell coaxial nanorods were degraded by post-annealing. The origin of the PL enhancement by the TiO2 coating is discussed.