Doping in nonaqueous solvents avoids the formation of
inert metal-aquo complexes and also enables a higher
reaction temperature. Cobalt-doped ZnO nanowires have
been synthesized by codissolving a desired amount of cobalt
acetate, Co(OAc)2, with zinc acetate in trioctylamine. Using
this approach, large quantities of single-crystalline, transitionmetal-doped
ZnO nanowires are obtained with excellent
purity, free from dopant overgrowth and secondary phases
(Figure 5). Other transition metals that have been incorporated
into the ZnO lattice using this method include
manganese, iron, and copper.