A simple one step approach to preparation of γ-MnOOH multipods and β-MnO2 nanorods

Materials Letters 03/2008; 62:1336-1338. DOI: 10.1016/j.matlet.2007.08.041

ABSTRACT Multipod-like γ-MnOOH and rod-like β-MnO2 nanocrystals are synthesized by oxidization of manganese sulphate hydrate (MnSO4·H2O) using sodium chlorate (NaClO3) as an oxidizing agent in a simple hydrothermal reaction system in the absence of any templates, catalysts, or organic reagents. The powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to characterize the as-prepared products. Based on the results of XRD and SEM, multipod-like γ-MnOOH can be transformed into rod-like β-MnO2 nanocrystals via one step synthetic route by simply increasing the reaction time while other conditions are kept constant. And a possible transfer mechanism via a nucleation–dissolution–anisotropic growth–recrystallization process is presented.