Hydrothermal synthesis of γ-MnOOH nanowires and α- MnO2 sea urchin-like clusters

γ-MnOOH nanowires and α- MnO2 sea urchin-like clusters have been selectively synthesized in two oxidation systems via a facile hydrothermal route. The γ-MnOOH nanowires were obtained from MnSO4 in the presence of H2O2 as an oxidizer in an alkaline solution, while the α- MnO2 sea urchin-like clusters were formed from MnSO4 in the presence of K2Cr2O7 as an oxidizer in an acid solution.