Abstract
Hexagonal ringlike superstructures (HRLSs) composed of hexagonal single-crystal Co-doped ZnO nanorods were synthesized via a combined hydrothermal and electrochemical process. The unique HRLSs are based on the oriented attachment of single-crystalline Co-doped ZnO nanorods of hexagonal shape driven by the electric dipole interactions of nanorods. The cathodoluminescence (CL) peaks show redshifts of about 30 and 57 nm from the band gap edge emission of the pure ZnO nanorods for 0.25 and 1% Co-doped ZnO nanostructures, respectively. Furthermore, high-temperature ferromagnetism was observed in both 0.25 and 1% Co-doped ZnO nanostructures at 350 K. The brand new member of the family of ZnO nanostructures may serve as a useful component for optical and magnetic applications in nanodevices. c 2008 American Chemical Society.