A new magnetic nano zero-valent iron encapsulated in carbon spheres for oxidative degradation of phenol

In this study, magnetic carbon encapsulated nano iron hybrids (nano Fe-0/Fe3C@CS) were synthesized via a novel one-pot hydrothermal method followed by self-reduction in N-2 atmosphere. The structural, morphological, and physicochemical properties of the samples were thoroughly investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), N-2 sorption isotherms and thermogravimetric analysis-differential scanning calorimetry (TGA-DSC). Catalytic performance of the as-synthesized nanoparticles was tested in activation of oxone (R) for phenol degradation in aqueous solutions. Superior catalytic performance was observed by complete removal of 20 ppm phenol within 10min. The formation of Fe3C was found to contribute to a better stability and magnetic separation of Fe-0/Fe3C@CS in its repeated uses. Both electron paramagnetic resonance (EPR) and classic quenching tests were carried out to investigate the mechanism of radical generation and evolution in phenol oxidation. Different from Co- and Mn-based catalysts in generation of sulfate radicals, Fe-0/Fe3C@CS selectively induced hydroxyl radicals for phenol degradation. (C) 2015 Elsevier B.V. All rights reserved.