One-pot synthesis of superparamagnetically modified zeolite chabazite for removal of Cs+ from radioactively contaminated water.

Composites of sodium-exchanged zeolite chabazite particles with attached superparamagnetic nanoparticles of Fe₃O₄ and CoFe₂O₄ ferrite spinels have been produced using a novel solvothermal route. These have been characterized by a combination of techniques, including powder x-ray diffraction, x-ray fluorescence spectroscopy, vibrating sample magnetometry, and both scanning and transmission electron microscopy. These confirm the nature of the attached nanoparticles, and the microscope images show a good dispersion of nanoparticles with a narrow size range deposited uniformly on the surface of the zeolite particles. The magnetization is of sufficient strength to allow magnetic separation from a solution. Both time and pH dependent Cs uptake experiments show that the magnetized systems are still excellent for the rapid uptake of Cs via an ion exchange process with no reduction in property due to the attached nanoparticles. [ABSTRACT FROM AUTHOR]