Preparation of porous and hollow Mn2O3 microspheres and their adsorption studies on heavy metal ions from aqueous solutions

Mn2O3 microspheres are prepared and used as adsorbent for removal of heavy metal ions. Morphology and structure of Mn2O3 microspheres are analyzed by SEM, TEM, XRD, XPS and N2 sorption technique. Effects of adsorbent concentration, ion concentration and agitation time on adsorption behavior are investigated. Adsorption isotherm and kinetics are also studied. The results show Mn2O3 microspheres have well-developed porous and hollow structure, demonstrating good potential on removal of heavy metal ions. Adsorption data fit better with Freundlich isotherms than Langmuir isotherms. Kinetic studies indicate adsorption behavior is described by pseudo-second-order kinetic model, and intra-particle diffusion plays a significant role.