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

Urchin-like nano/micro-hybrid α-MnO2 balls were prepared through the hydrothermal reaction of H2SO4 and KMnO4 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-MnO2 is composed of single crystalline α-MnO2 nanorods. The formation mechanism of urchin-shaped α-MnO2 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.