Hydrothermal synthesis and characterisation of MnO2 nanostructures

α-, β- and δ-MnO2 nanostructures have been successfully prepared by a common hydrothermal method based on the redox reactions of MnO4− and/or Mn2+, and the effect of varying the hydrothermal time to synthesise MnO2 nanostructures was investigated along with their influence on crystallinity and morphological properties. XRD and SEM studies revealed a variety of structures ranging from nanostructured surface with a distinct plate like morphology to nanorods depending upon the hydrothermal reaction time; increasing the amount of individual nanorods in the materials prepared with longer hydrothermal reaction. BET studies showed that the surface area of synthesised α-MnO2 nanorods varied from 100 to 150 m²/g. Moreover, effect of reactants molar ratio on crystallinity and structural properties have been successfully considered by XRD and SEM methods.