Microwave-assisted synthesis of hierarchical ZnO nanostructures

Abstract

The hierarchical zinc oxide nanosheet spheres were synthesized via a facile and fast microwave assisted ionic liquid method, in an environmental-friendly reaction medium containing glutamic tetrofluoroborate (an amino acid ionic liquid), zinc acetate and excessive sodium hydroxide. The amount of ionic liquid played an important role in the formation of various ZnO nanostructures. The microwave irradiation also had influence on the morphology. Using the conventional solution synthesis route, in the absence of glutamic tetrofluoroborate, the nanoneedle-like ZnO structures were fabricated, and without the aid of microwave, the clew-like hierarchical ZnO nanosheet spheres were obtained. The results revealed that the as-prepared ZnO nanostructures showed good crystallinity with the hexagonal wurtzite structure, and a decrease in grain size with the increase of glutamic tetrofluoroborate content. Therefore, the selected materials and approach allowed the synthesis of hierarchical ZnO nanostructures in a fast and controllable manner.