Facile preparation of monodisperse ZnO quantum dots with high quality photoluminescence characteristics

We report a new method that enables the facile synthesis of monodisperse zinc oxide (ZnO) quantum dots (QDs) with high quality photoluminescence (PL) characteristics. In the proposed method, ZnO QDs are grown on acid-treated multiwalled carbon nanotubes (a-MWCNTs) under remarkably mild reaction conditions (low temperature, short time, atmospheric pressure, and no need for subsequent thermal annealing). The ZnO QDs grown on the a-MWCNTs were monodisperse and highly crystalline, and had diameters of about 7 nm. Moreover, the a-MWCNT-grown ZnO QDs exhibited a definitive blue emission without defect-related blue-green emission, features that are indicative of definite quantum confinement effects and high quality.