A simple hydrothermal route to synthesis of rod-like MnOOH and spindle-shaped MnCO3

Abstract

A simple hydrothermal route was developed to synthesis of rod-like manganese oxyhydroxide (MnOOH) and spindle-shaped manganese carbonate (MnCO3) based on the redox reactions between potassium permanganate (KMnO4) and β-cyclodextrin (β-CD) without extra surfactant or template. At the mass ratio between β-CD and KMnO4 of 0.25, MnOOH nanorods with the diameter about 40–400 nm and the length in the range of 2–10 μm could be facilely prepared in high yield. However, spindle-shaped MnCO3 microparticles were prepared when the mass ratio between β-CD and KMnO4 was increased to 1.5. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The formation mechanisms of rod-like MnOOH and spindle-shaped MnCO3 were preliminarily discussed.