Synthesis, Characterization, and Photocatalytic Application of Different ZnO Nanostructures in Array Configurations

Arrays of well-aligned one-dimensional ZnO nanostructures (nanowires, nanorods, nanoribbons, nanobuds, and flocky nanorods) with high aspect ratios have been grown on zinc substrates by a solution-phase method using a mixture of ethylenediamine, ethanol, and water. The morphology of the ZnO nanostructures has been modulated by controlling the concentration of ethylenediamine and ethanol and regulating the reaction temperature. Chemical and structural analyses and emission spectra show that the arrays of ZnO nanorods favor nearly stoichiometric composition and good crystallization quality, whereas the arrays of ZnO nanowires, nanoribbons, nanobuds, and flocky nanorods confine a considerable amount of oxygen vacancies. The photocatalytic effect investigated at decomposition of methyl red correlates with the defect-related emission properties of these nanoarrays. Particularly ZnO nanobuds and flocky nanorods arrays have been found to be effective photocatalysts.