Size-controlled synthesis and photocatalytic degradation properties of nano-sized ZnO nanorods

ZnO nanorods with various ratios of length to diameter have been synthesized by combining the facile sol-gel process with hydrothermal methods. The obtained ZnO nanorods have been investigated by using electron microscopy, X-ray diffraction, electronic absorption and photoluminescence spectroscopy. The results show that the spectral properties of the ZnO nanorods can be adjusted by controlling the concentration of reactant during hydrothermal process. The photodegradation of methylene blue in the presence of ZnO has also been investigated detailedly. It is found that the ZnO nanorods prepared in 12.0 mM reactant condition exhibit the highest activity which is six times as large as the ZnO seeds, and that the activity of the optimum ZnO can reach above 80% after repeated uses of 5 times. (C) 2011 Elsevier B.V. All rights reserved.