MnO2/Fe2O3 Nanocomposite Sorbent for Gas Capture

A special type of hydrous MnO2/Fe2O3 nanocomposite was prepared using a two-step precipitation method. Fe2O3·xH2O nanoparticles, precipitated from Fe(NO3)3 and NH3·H2O, were proposed to be embedded into the mesoporous network of MnO2, which was synthesized by the aqueous reaction between KMnO4 and glucose. The nanocomposite with an equal Mn/Fe molar ratio shows strong synergy, with a specific surface area of 388 m2/g, much larger than those of individual MnO2 or Fe2O3·xH2O samples. As a result, this nanocomposite exhibited the highest adsorption capacity for NH3 and SO2. The isolation of Fe2O3·xH2O by MnO2, leading to mitigated aggregation of Fe2O3·xH2O nanoparticles, was characterized by transmission electron microscopy, powder X-ray diffraction, and vibrational spectra. X-ray absorption spectroscopy was used to study the interaction between Fe2O3·xH2O and MnO2 after the formation of composites. This typical method for the preparation of nanocomposites proved to be effective to improve porosity, as demonstrated by N2 adsorption isotherms and small-angle X-ray scattering