The author prepared zinc oxide (ZnO) rods using chemical synthesis in surfactant solutions, and investigated the surfactant concentration dependence on their structure and photocatalytic properties. With increased surfactant concentration, the ZnO morphology changed from a single straight rod to radial-shaped rods, with progressive lattice shrinkage of ZnO crystals. In the emission bands Of ultraviolet and yellow, the photoluminescence intensities were decreased with increasing surfactant concentration. These results suggest that the surfactant molecules impart the radial structure through chemical activation of the ZnO surface, which engenders formation of dense lattice defects. The photocatalytic activity was improved through a two-step growth of the radial-shaped rods because of the existence of good crystallinity and interstitial nanospaces of radial-shaped rods. (C) 2009 Elsevier Inc. All rights reserved.