Growth of layered basic zinc acetate in methanolic solutions and its pyrolytic transformation into porous zinc oxide films

Abstract

Layered basic zinc acetate (LBZA), Zn5(OH)8(CH 3COO)2·2H2O, was deposited on glass substrates by a chemical bath deposition (CBD) method using methanolic solutions of zinc acetate dihydrate. The substrates were put into bottles filled with the solutions and sealed up and were kept at 60°C in a drying oven. Immersion time necessary for the deposition of LBZA films was typically more than 28 h. This was a key to inducing heterogeneous nucleation of LBZA through control over a degree of supersaturation in the evolution of a unique, nest-like morphology. Hydration water contained by zinc acetate dihydrate was quantitatively enough to promote hydrolysis of zinc acetate. The LBZA films were transformed into nanocrystalline, porous ZnO films without morphological deformation by heating at 150°C in air. A mechanism of the formation of the nest-like morphology was discussed based on nonaqueous solution reactions, nucleation, and crystal growth during the CBD process. © 2003 Elsevier Inc. All rights reserved.