Potassium Ferrite (KFeO2): Synthesis, Decomposition, and Application for Removal of Metals Academic Article uri icon

abstract

  • 2015 by American Scientific Publishers. Potassium ferrite (KFeO2) was synthesized by a new simple thermal process from natural waste ferrihydrite and KNO3 precursors. The synthesized KFeO2 showed considerable instability when it was in contact with water and CO2 of the humid air. The decomposition of KFeO2 followed first-order kinetics with rate constants as 0.9310-1 h-1 and 1.8610-1h-1 at relative humidity of 30-35% and 65-70%, respectively. The products of decomposition, crystalline KHCO3 and nanocrystalline iron(III) oxides in the molar ratio of 2:1, were characterized in detail by X-ray powder diffraction, low-temperature and in-field 57Fe Mssbauer spectroscopy, magnetization (SQUID) measurements, thermal analysis, and scanning and transmission electron microscopy. Washing and subsequent air drying of the decomposed products of KFeO2 yielded monodisperse superparamagnetic maghemite (-Fe2O3) nanoparticles, which turned out to be efficient as magnetic sorbents for removing Cu2+ in water. A direct addition of solid KFeO2 into water containing Cu2+ ions yielded rapid coagulation of iron(III) oxyhydroxides, which subsequently removed Cu2+ more efficiently compared to its sorption on the pre-formed maghemite nanoparticles.

published proceedings

  • SCIENCE OF ADVANCED MATERIALS

author list (cited authors)

  • Machala, L., Filip, J., Prucek, R., Tucek, J., Frydrych, J., Sharma, V. K., & Zboril, R.

citation count

  • 6

complete list of authors

  • Machala, Libor||Filip, Jan||Prucek, Robert||Tucek, Jiri||Frydrych, Jiri||Sharma, Virender K||Zboril, Radek

publication date

  • March 2015