Chelation-mediated aqueous synthesis of metal oxyhydroxide and oxide nanostructures: combination of ligand-controlled oxidation and ligand-cooperative morphogenesis.
We have synthesized nanostructures of iron and cobalt oxyhydroxides and manganese oxides in aqueous solution containing a chelating agent. Nanosheets of FeOOH and NaxMnO2 and nanoflakes of CoOOH were generated from the corresponding divalent metal salts and ethylenediaminetetraacetate (EDTA) by one-pot synthesis under ambient conditions. The chelating agent fulfilled multiple roles in the reaction process and morphogenesis leading to two-dimensional nanostructures. Coordination to the divalent metal ions inhibited rapid precipitation of metal hydroxides and mediated oxidation to tri- and tetravalent species by dissolved oxygen. Along with the deposition, the two-dimensional and single-crystal nanostructures were also associated with interactions of the chelating agent. Therefore, this approach can be regarded as a combination of ligand-controlled oxidation and ligand-cooperative morphogenesis. Parallel control of the reaction and the morphology was achieved by a simple approach. The model cases suggest that tailoring chelation can facilitate the design of other metal oxide nanomaterials.
Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
Yuya
Y
Oaki
Hiroaki
H
Imai
D002614:Chelating Agents / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D008024:Ligands; D008670:Metals / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D010084:Oxidation-Reduction; D013057:Spectrum Analysis / Q000379:methods; D014961:X-Ray Diffraction
D002614:Chelating Agents; D006878:Hydroxides; D008024:Ligands; D008670:Metals