has been synthesized in a single alkali treatment. Novel formation mechanisms of the nanotubes are proposed based on a series of experiments. In the process NaOH can be regarded as a catalyst and a reusable source. The synthetic method is extremely inexpensive and may be applied to synthesize other oxide nanostructures. (W. Zhou, L.-M. Peng, et al., September 3, Adv. Mater. 2002, 14, 1208-1211)