ZnO hierarchical structures synthesized via hydrothermal method and their photoluminescence properties

The controlled synthesis of ZnO hierarchical structures has been successfully realized in a large scale via a simple hydrothermal method. It was demonstrated that the morphology of the final products was simply tuned by adding different amounts of soluble salt. ZnO microparticles were prepared when no soluble salt was added, whereas microspheres and nanoflowers were selectively prepared in the presence of different amounts of NaF. ZnO nanosheets were obtained when adding appropriate amount of NaCl, Na2SO4, or K2SO4. ZnO nanobelts were obtained in the presence of appropriate amount of sodium citrate (C6H5Na3O7). The photoluminescence (PL) properties of those products were researched, and the origin of the PL was discussed.