Synthesis and morphology-dependent antimicrobial activity of cerium doped flower-shaped ZnO crystallites under visible light irradiation

Cerium doped flower-shaped ZnO crystallites were prepared via a facile microwave-assisted hydrothermal method with zinc nitrate hexahydrate as zinc sources, cerium (III) nitrate nonahydrate as dopant. The obtained samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), Brunauer-Emmett-Teller surface area measurement (BET), energy dispersive spectroscopy (EDS) and UV⿿vis diffuse reflectance spectroscopy. Antimicrobial activity of the samples against Candida albicans ( C. albicans ) and Aspergillus flavus ( A. flavus ) was compared with pure ZnO under visible light sources. The results indicated that cerium doped flower-shaped ZnO crystallites had different crystal structure with the increased levels of cerium content. Besides, the band gap of ZnO crystallites decreased and its crystallinity increased with the adding of cerium ion. In particular, increasing levels of the cerium dopant more than 0.8% results in decreased optical band gap (3.06   eV) and enhanced antimicrobial activity against C. albicans (75%) and A. flavus (80%) under visibler light sources.