Controlled growth of hierarchical ZnO nanorods with periodical structure under negative feedback mechanism

A new kind of hierarchical ZnO nanorod with a periodical structure was successfully synthesized using a mixture of Zn, ZnO and carbon as the source through the chemical vapour deposition method. A self-catalyzed growth process dominated by a negative feedback mechanism was proposed to explain its growth. Combining the experimental conditions, the change in reagent supersaturation through a whole reaction was analysed and a three-step growth model was built. Two contrasting experiments were further conducted to study the relation between microscopic conditions and the growth behaviour of the nanostructure. The results and discussions were a beneficial exploration and could reference for controlled growth of nanostructure through modulating the supersaturation by source. Furthermore these obtained hierarchical nanostructures are also expected to have potential applications as functional blocks in future nanodevices.