Microwave hydrothermal synthesis of K+ doped ZnO nanoparticles with enhanced photocatalytic properties under visible-light

Potassium doped ZnO crystallites were successfully synthesized via a microwave hydrothermal method with Zn(NO3)(2)center dot 6H(2)O and KNO3 used as source materials. The phase and microstructure of the as-prepared Zn1-xKxO crystallites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ultraviolet-visible (UV-vis) spectrum and photochemical reaction instrument were used to analyze the photocatalytic properties of the particles. Results show that the diffraction peaks of the K+ doped ZnO crystallites shifted slightly toward higher angle when increasing K+ doping concentration was increased from 0% to 0.5%. Moreover, morphology of these ZnO crystallites transforms from lamellar structure to small granules with higher absorption in UV region and narrower band gaps (E-g). Finally, comparing the products to pure ZnO particles exhibits obviously improved photocatalytic properties of the K+ doped ZnO crystallites. (C) 2013 Elsevier B.V. All rights reserved.