Facile synthesis of mesoporous α-Mn 2 O 3 microspheres via morphology conserved thermal decomposition of MnCO 3 microspheres

Abstract In this article, we report on the synthesis and characterisation of novel mesoporous α-Mn 2 O 3 microspheres obtained by the thermal decomposition of hydrothermally grown MnCO 3 . The porous, hierarchical Mn 2 O 3 microspheres were obtained without the use of any structural directing agents or templates. The self-sacrificing template character of the hydrothermally grown MnCO 3 is clearly presented here. Body centred cubic phase pure crystalline structure of Mn 2 O 3 was acquired at 600 °C, whereas a minor Mn 3 O 4 phase was detected at 500 °C. The microsphere-like morphology of the intermediate precursor and the final products was clearly observed in the field emission scanning electron microscopy (FESEM) images, which depicted the morphology conserved thermal decomposition process. Roughly spherical and elongated Mn 2 O 3 sub-nanoparticles were hierarchically gathered inside the microspheres, which points to the development of a mesoporous texture, as confirmed by the transmission electron microscopy (TEM) and porosity studies. The optical properties studied using photoluminescence spectroscopy indicated its applications under UV-light.