Polyethylenimine-Guided Self-Twin Zinc Oxide Nanoarray Assemblies

摘要

Well-oriented and twin ZnO nanoarray assemblies have been fabricated using the aqueous solution deposition technique at low temperature. Polyethylenimine was added to the zinc nitrate hexahydrate-hexamethylenetetramine aqueous Solution during the deposition processes at 88 degrees C. The formation mechanism of twin ZnO nanoarray assemblies was clarified by X-ray diffraction, a field emission scanning electron microscope and high-resolution transmission electron microscope. The addition of polyethylenimine resulted in the formation of zinc hydroxide and zinc hydroxide nitrate dihydrate (Zn-5(OH)(8)(NO3)(2)center dot 2H(2)O) as the intermediate phases. In Situ forced hydrolysis of the cloudlike intermediate phase Zn-5(OH)(8)(NO3)(2)center dot 2H(2)O effectively provided nucleation sites and reduced the interface energy barrier for ZnO crystal growth, and promoted preferential growth along the [0001] direction by heterogeneous nucleation through the dissolution-reprecipitation of zinc hydroxide. The formation of twin ZnO assemblies Should be attributed to kinetic confinement and thermodynamic motivation.