Influence of Anions on the Morphology of Nanophase <I>α</I>-MnO<SUB>2</SUB> Crystal via Hydrothermal Process

The alpha-MnO2 nanocrystal nanowires, nanoplates, and nanoflowers have been successfully synthesized by a common hydrothermal treatment of different solutions containing KMnO4 and NH4X (X = Cl-, Ac-, NO3-, SO4(2-), and PO4(3-)) at 140 degrees C for 24 h. The influence of anions on the morphology of final product is discussed. According to our experimental results, we proposed a possible mechanism of the formation of different morphologies of nano-phase alpha-MnO2 and considered that the growing process was due to the initial plate-like MO(x) absorbing different anions and cooperation with them, which contributes to the final morphology of the product.