Microwave hydrothermal synthesis of Sr2+ doped ZnO crystallites with enhanced photocatalytic properties

Pure and Sr2+ doped ZnO crystallites were successfully synthesized via a microwave hydrothermal method using Zn(NO3)(2)center dot 6H(2)O and Sr (NO3)(2)center dot 6H(2)O as source materials. The phase and microstructure of the as-prepared Zn1-xSrxO crystallites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ultraviolet-visible spectrum (UV-vis) and photochemical reaction instrument were used to analyze the photocatalytic properties of the particles. XRD results show that the diffraction peaks of the as-prepared Zn1-xSrxO crystallites shifted slightly toward lower 2 theta angle with the increasing of Sr2+ doping concentration from 0% to 0.3%. The pure ZnO crystallites with lamellar structure are found transforming to a hexagonal columnar morphology with the increase of Sr2+ doping concentration. UV-vis analysis shows that the particles have a higher absorption in UV region with a slightly decreased of optical band (E-g) gap. The photocatalytic activity of Sr2+ doped ZnO crystallites was evaluated by the Rhodamine B (RhB) degradation in aqueous solution under visible-light irradiation. Compared with the pure ZnO particles, the photocatalytic properties of the Sr2+ doped ZnO crystallites are obviously improved. The photocatalysis experiment results demonstrate that the 0.1% Sr2+ doped ZnO exhibits the best photocatalytic activity for the degradation of Rhodamine B. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.