shows its magnified FESEM image of rectangular shaped structures. The term ‘‘nanobatlike structure’’ in this study is used to describe the structural evolution that each CuO nanorods shows acicular growth behavior at one end and become a rectangular shaped structure as growth proceeds. It is important to note that most of the rectangular shaped nanorods show this typical morphology. The well-faceted end and side surfaces of perfectly grown rectangular shaped nanobat-like structure are also clearly observed in Fig. 2(c)