Novel branched γ-MnOOH and β-MnO2 multipod nanostructures

A convenient hydrothermal processing followed by a postheat treatment route is proposed to synthesize well-dispersed, branched beta-MnO2 multipods from a branched gamma-MnOOH precursor. The key steps in our approach are as follows: ( 1) by controlling the reactant concentration and reaction time, the monoclinic phase of MnOOH with novel branched multipod nanostructures is synthesized via the hydrothermal reaction of MnSO4 center dot H2O and NaClO3 at 160 degrees C for 200 min; ( 2) the prepared branched gamma-MnOOH multipods are heated under an air atmosphere at 400 degrees C for 2 h, and the branched beta-MnO2 nanostructures can be successfully obtained without changing the precursor morphologies. The new structures presented here enrich the nanoscale community with new basic materials and offer a new approach for increasing structural complexity and enabling greater potential applications. Furthermore, brief discussions about their formation mechanisms provide insight into the formation processing of other transition-metal oxide multipods.