Nanoflower-like Yttrium-doped ZnO Photocatalyst for the Degradation of Methylene Blue Dye.

Pure ZnO and Yttrium-doped (Y-doped) ZnO at various mol% with flower-like nanostructures are synthesized by a microwave-assisted sol-gel method, followed by investigating the morphologies, crystal structures, optical properties and photocatalytic performances. While the phase formations are detected by X-ray diffraction technique, both scanning and transmission electron microscopy images clearly depict the flower-like morphology of ZnO and Y-doped ZnO samples. Formation of flower petals is from the nanoparticles that grew and connected by orientation attachment process. The flower-like architecture is addressed in terms of an Ostwald ripening mechanism. The UV-Vis absorption studies show enhanced absorption for the Y-doped ZnO, whereas the photoluminescence spectra confirm the significance of sample defects in the photocatalytic degradation of organic pollutants. Effects of various experimental parameters such as the amount of photocatalysts, dye concentration and dopant concentration on the dye degradation are also optimized.