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

Multifunctional Zn 1 x La x O and Zn 1 x Mg x O 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 ¼ 0.05. The Zn 0.9 Mg 0.1 O nanostructure showed the widest E g value of 3.30 eV. The Zn 0.95 Mg 0.05 O 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 ). & 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserv