Fe3O4 Nanoparticles and Carboxymethyl Cellulose: A Green Option for the Removal of Atmospheric Benzene, Toluene, Ethylbenzene, and o-Xylene (BTEX)

In this work, we investigate the interaction of gaseous benzene, toluene, ethylbenzene, and o-xylene (BTEX) with Fe3O4 nanoparticles and demonstrate the potential application of Fe3O4 nanoparticles as adsorbents for BTEX. On the basis of X-ray diffraction, transmission electron microscopy, gas chromatography-mass spectrometry, and gas chromatography-flame ionization detection results, using toluene as a model compound, we find that adsorption is of a heterogeneous nature. At relatively high concentrations of toluene (300-2790 ppmv), X-ray photoelectron spectroscopy results indicate an increase in the divalent cations relative to the trivalent cations of Fe3O4 nanoparticles, which is possibly triggered by nanoscale effects. Removal efficiency experiments show that Fe3O4 nanoparticles (4 g) reduce 100 ppmv of BETX in air by 83 +/- 8%, 95 +/- 5%, 97 +/- 1%, and 98 +/- 2%, respectively. Comparable removal efficiencies were observed for recycled Fe3O4 nanoparticles. Toluene was also removed from a flow by Fe3O4 nanoparticles bound together with carboxymethyl cellulose, without releasing undesired aerosols. Fe3O4 nanoparticles (bare and as a composite) show potential as practical and environmental friendly materials for the remediation of BTEX from air.