Diameter-controlled synthesis of α-Mn2O3 nanorods and nanowires with enhanced surface morphology and optical properties

Single crystalline alpha-Mn2O3 nanorods, and nanowires with and without nanoparticles on them have been successfully synthesized by a template-free hydrothermal route. The variation in hydrothermal temperature has not only affected the diameter of the nanostructure but also noticeably affected the morphology and optical properties of the alpha-Mn2O3 nanostructure. The influence of temperature on the diameter, crystallinity, surface morphology and optical properties of the alpha-Mn2O3 nanostructure have been characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, transmission electron microscopy, high resolution transmission electron microscopy, Raman spectroscopy and UV-visible spectroscopy and photoluminescent (PL) spectroscopy. The results showed in our experimental conditions that single crystalline nanorods of the alpha-Mn2O3 were obtained at a temperature of 180 degrees C, while single crystalline nanowires were obtained by increasing the temperature to 240 and 300 degrees C. Nanowires with nanoparticles on them were obtained by increasing the temperature to 240 degrees C and nanowires without nanoparticles on them were obtained by increasing the temperature to 300 degrees C. The nanorods and nanowires obtained had a well-defined morphology. The nanowires synthesized at 300 degrees C exhibited an intense orange band PL spectrum.