Nanostructures and Nanostructured Coatings of Oxides obtained through Microwave Irradiation, with emphasis on ZnO

Metal oxide nanostructures are particularly important because of the significant  alteration in their physical and chemical properties in the nanometer regime. Manydifferent synthesis strategies have been developed by the researchers over time to prepare metal oxide nanostructures having tailored geometry. We report, the synthesis of metal oxide nanostructures and thin film deposition of nanostructured metal oxides from the corresponding metalorganic complexes, using microwave irradiation-assisted chemical synthesis, either in the presence or the absence of a surfactant. Nanoparticles of some functionally advanced binary/ternary metal oxides (MnO2, ZnO, NiO, CdO, Fe2O3, Ga2O3, Gd2O3, ZnFe2O4, ZnMn2O4 etc) have been synthesized using metal acetylacetonates as the starting precursor material and microwave as the source of energy, in a process developed in detail in our laboratory. Emphasis has been placed on the synthesis of ZnO nanostructures (nanoparticles, nanorods, nanotubes, nanoflowers) using a variety of different surfactants (polymeric or ionic), as well as different solvents. Optical characteristics (“Near-white light emission from ZnO nanostructures and conversion of all primary colors to white light”) of ZnO nanostructures (powder or thin film) have been studied. We have also studied the shape transformation of ZnO nanorods/nanotubes at relatively low temperatures (up to 900 oC)