Controlled growth of self-assembled ZnO thin films and characterization of their photocatalytic properties

Abstract

Self-assembled ZnO thin films with controlled sizes were successfully prepared by varying the processing parameters. The films have a photonic band gap, which extends the absorption range to the visible light region. The photocatalytic activities of the ZnO thin films were evaluated by the degradation of methyl orange (MO). The crystal structure of ZnO was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the ZnO thin films exhibit good photocatalytic activities under sunlight. Furthermore, the photocatalytic activities of the ZnO thin films were highly dependent on sphere size. With an increase in ZnO sphere size, the degradation efficiency toward MO decreased. The photodegradation can be described using a pseudo-first-order kinetics equation. © Editorial office of Acta Physico-Chimica Sinica.