title: Rapid microwave-assisted synthesis of hierarchical ZnO hollow spheres and their application in Cr(VI) removal.
abstract: A rapid one-pot synthesis of hierarchical ZnO hollow spheres consisting of nanoparticles was realized by a facile microwave-assisted solvothermal method using ethanol as the solvent. According to the time-dependent observation of the formation process, a tentative mechanism based on ethyl acetate bubble-templating self-assembly of ZnO nanoparticles was proposed for the formation of the ZnO hollow spheres. Compared with the conventional heating, the microwave irradiation resulted in a significantly shortened reaction time (within 30 min) and considerably improved quality of the ZnO hollow spheres, such as narrower size distribution and more regular morphology, owing to the high heating rate and thus the accelerated reaction rate. It was shown that the microwave-assisted synthesis of ZnO nanostructures with tunable morphologies can be realized by judicious selection of appropriate solvents. The obtained ZnO hollow spheres exhibited an excellent adsorption capacity towards Cr(VI) ions in water because of their high surface area for adsorption and a good ability to preserve the accessible surface.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Stable and Unstable Species, College of Chemistry, Peking University, Beijing, People's Republic of China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhao
authors.forename: Limin
authors.initials: L
authors.lastname: Qi
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000737:chemistry* / Q000302:isolation & purification*; D003460:Crystallization / Q000379:methods; D008422:Materials Testing; D008872:Microwaves; D008968:Molecular Conformation / Q000528:radiation effects; D054118:Nanospheres / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010316:Particle Size; D016062:Porosity / Q000528:radiation effects; D013499:Surface Properties / Q000528:radiation effects; D015034:Zinc Oxide / Q000737:chemistry* / Q000528:radiation effects*
chemical_list: D002857:Chromium; D015034:Zinc Oxide