One method to prepare nanosized Mn2O3 is the thermal decomposition.
a-Mn2O3 particles were usually prepared by heating
MnO2 or MnCO3 in air at temperatures of 600–800 C [17]. Sphereor
cube-like a-Mn2O3 was obtained at 550 C through the decomposition
of the MnCO3 precursors synthesized via a hydrothermal
reduction process [18]. Nanofiberous a-Mn2O3 was prepared by
calcination of c-MnO2 nanowires at the temperature above
600 C [5]. Monodisperse nanocrystals of MnO of length 7 nm have
been synthesized by thermal decomposition of [Mn(ac)2],
(ac = acetate), in the presence of oleic acid at high temperature
[19]. Seo et al. [20] prepared Mn3O4 nanocrystals from [Mn(acac)2],
(acac = acetylacetonate). Zhang and coworkers prepared nanocrystals
MnO and Mn3O4 via thermolysis of manganese formate in
coordinating solvent at temperatures ranging from 170 to 250 C