Facile Synthesis of Quasi Spherical ZnO Nanoparticles with Excellent Photocatalytic Activity

In this article, we report on the synthesis, characterization and photocatalytic activity of quasi spherical ZnO nanoparticles obtained by an egg white assisted facile sol-gel type wet method. The material was characterized for its structural, textural and optical properties. The hexagonal wurtzite crystalline structure of ZnO with high phase purity was confirmed by the X-ray diffraction analysis. The mesoporous texture generated from the inter-agglomeration of ZnO nanoparticles was clearly shown in the transmission electron microscopy (TEM) images. The N-2 sorption analysis indicated a specific surface area of 18 m(2)/g, with monomodal mesoporosity. The optical studies had shown the decreased optical band gap (3.28 eV) of the sample with the existence of a number of crystal defects, especially oxygen vacancies in the sample. The aquatic dye pollutants were effectively degraded under UV irradiation over the ZnO nano photocatalysts. They were also found to be reusable up to five consecutive runs without loss in catalytic activity, indicating their high photostability against photocorrosion.