Morphology control of ZnO nanostructures

Abstract

Highly crystalline zinc oxide (ZnO) nanomaterials are synthesized using a seeded growth sol-gel method. In order to control the morphology and the dimensionality of ZnO crystals, a double hydrophilic block copolymer, the Polyacrylic acid-Polyacrylamide (PAA-PAM), was introduced during the growth step. It was shown, first, that depending on the amount of PAA-PAM copolymer, different morphologies of ZnO particles precipitated from homogeneous solutions were obtained, such as ZnO nanostructured spheres or flat hexagonal crystals. Secondly, the dimensionality of ZnO objects grown from seeds on a substrate could be tuned by varying the amount of copolymer leading to ZnO films with variable characteristics. Thus, systematic studies were done in order to investigate the influence of copolymer addition on ZnO nanomaterial morphologies and then explain the mechanisms of the morphological and dimensional modifications.