Fine particles of manganese oxide were synthesized by following the controlled precipitation method. For this, an aqueous solution of manganese chloride (0.01–0.06 molL-1) were allowed to react with an aqueous solution of ammonium carbonate (0.01–0.03 molL-1) at various temperatures (25-60 ºC) for different periods of time (10-40 min) with and without agitation (magnetic stirring/sonication). It was observed that the applied experimental parameters significantly affected different properties of the obtained solids. Extensive optimization of experimental parameters led to produce powders, composed of particles of uniform morphological features. The targeted particles were achieved only under limited experimental conditions. Selected batches were calcined at the elevated temperature (800 ºC) with the controlled heating rate of 5, 10 and 15ºC/min). Scanning electron microscopic analysis and X-ray diffractometry of the calcined materials showed that neither the heating rate nor the final temperature affected the original morphology of the particles. Moreover, the same batches of the solids were also characterized by FTIR, XRD, and TG/DTA. It was found that the as synthesized particles were highly alike in morphology but were weakly crystalline in nature. However, heat treatment of the obtained particles resulted in Mn2O3 particles of orthorhombic crystal system of high crystallinity.

Khalida Akhtar, Syed Sajjad Ali Shah, Muhammad Gul, Ikram Ul Haq and Naila Zubair