Optical, photocatalytic and bactericidal properties of Zn1-xLaxO and Zn1-xMgxO nanostructures prepared by a sol-gel method

Multifunctional Zn1-xLaxO and Zn1-xMgxO nanostructures were successfully synthesized through a sol-gel method. The crystal structure, morphology, specific surface area and thermal behavior were investigated by X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and a thermogravimetric and differential thermal analyzer (TG-DTA), respectively. The optical properties were determined with a UV-vis spectrophotometer and a photoluminescent spectrometer. The crystallite size decreased when the La and Mg concentrations increased to x=0.05. The Zn0.9Mg0.1O nanostructure showed the widest E-g value of 3.30 eV. The Zn0.95Mg0.05O nanostructure exhibited the highest efficiency for the photocatalytic degradation of methylene blue (MB) with a rate constant (k) of 0.0440 min(-1). Both La- and Mg-doped ZnO nanostructures inhibited Staphylococcus aureus (S. aureus) and to a less extent Escherichia coli (E. coli). (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.