Nucleation site and mechanism leading to growth of bulk-quantity Mn 3O4 nanorods

We report a simple and effective method for the generation of bulk-quantity nanorods of manganese oxide, Mn3 O4, under surroundings of a suitable surfactant and alkaline solution. It is found that the Mn3 O4 nanorod is smooth, straight, and that the geometrical shape is structurally perfect, which is produced with lengths from several hundreds nanometers to a few micrometers, and diameters range from 10 nm to 30 nm. We amazedly found that the dripping speed of the NaOH solution plays an important role in formation of bulk-quantity Mn3 O4 nanorods. The difference of dripping speed of the NaOH solution leads to a large difference of Mn3 O4 morphologies, which is observed in the transmission electron microscopy images. The growth of the Mn3 O4 nanorods is suggested first to follow a self-catalyzed solution-liquid-solid mechanism. © 2005 American Institute of Physics.