Synthesis and formation mechanism of urchin-like nano/micro-hybrid α-MnO2

Abstract Urchin-like nano/micro-hybrid α-MnO 2 balls were prepared through the hydrothermal reaction of H 2 SO 4 and KMnO 4 without the use of templates, surfactants or other additives. The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy and X-ray diffraction (XRD). It indicates that the urchin-like α-MnO 2 is composed of single crystalline α-MnO 2 nanorods. The formation mechanism of urchin-shaped α-MnO 2 was proposed and explained in detail on the basis of the time-dependent designed experiments combined with XRD analysis and TEM observations of the intermediates during the formation process.