Microwave-assisted method for preparation of Sb-doped ZnO nanostructures and their photocatalytic activity

Nanostructures of Sb-doped ZnO with 0.00, 0.03, 0.06, 0.10 and 0.15 mol fractions of Sb⁺³ ions were prepared by a one-pot method in water under microwave irradiation for 5 min. Powder X-ray diffraction studies display that the nanostructures are excellently crystallized in the form of Wurtzite hexagonal crystalline phase and doping Sb⁺³ ions does not change structure of ZnO. Moreover, size of the nanostructures decreases with increasing mole fraction of Sb⁺³ ions. Scanning electron microscopy and transmission electron microscopy images show that morphology and size of the nanostructures are changing with mole fraction of the dopant. In Fourier transform infrared spectra, intensity of the characteristic peak corresponding to Sb–O bond gradually increases with mole fraction of Sb⁺³ ions. UV–vis diffuse reflectance spectra of the nanostructures are similar to each other and they have a maximum of about 357 nm. Photocatalytic activity of the nanostructures was investigated by degradation of methylene blue under UV irradiation. For the nanostructures with 0.10 mol fraction of Sb⁺³ ions, the degradation rate constant increases nearly two times relative to pure ZnO. In addition, influence of various operational parameters on the degradation activity was investigated and the results were discussed.