Self-assembly of periodic ZnO/C multilayers on Zn nanowires

Abstract

In a previous study, we observed periodic polycrystalline-ZnO∕amorphous-C multilayers self-organized on the surface of Zn nanowires, which were dispersed on the amorphous carbon film at ambient conditions after 1500 h. Such self-assembled multilayers with individual layer thickness of ≃2nm have been reproduced through a simple chemical reaction between the Zn nanowires and the CO2 gas. Transmission electron microscopy is employed to investigate the evolution of the Zn nanowire during its reaction with the CO2. A systematic study is carried out and a four-step mechanism—gas phase diffusion, interfacial chemical reaction, phase separation, and self-alignment—is proposed to explain the formation of such nanostructures. The parameters that affected the self-assembly process including the crystallinity of the original native zinc oxide sheath wrapping the Zn nanowires, the reaction temperature, and the reacting gases are discussed in detail based on the experimental observations.