Fe3O4@C Core-Shell Carbon Hybrid Materials as Magnetically Separable Adsorbents for the Removal of Dibenzothiophene in Fuels

Herein, we demonstrate a new class of core-shell magnetic carbon hybrid materials (Fe3O4@C) for remarkable adsorptive desulfurization of dibenzothiophene (DBT), which have been successfully prepared through hydrocarbonization of glucose on the surface of Fe3O4 and the subsequent pyrolyzation process. The as-obtained Fe3O4@C retains amorphous nature of carbon shells with a large surface area and displays an increase of iron atoms as active sites under elevated pyrolyzation temperature which is favorable in the adsorption of sulfur-containing species through physical and chemical adsorption, respectively. We investigate the adsorption capacity and efficiency of Fe3O4@C as a magnetically adsorbent for the removal of DBT in model oils under various experimental conditions including the adsorbent obtained at different temperatures, the amount of adsorbents, the DBT initial concentration, the regeneration approach, as well as the interference species. Our results demonstrated that the as-obtained Fe3O4@C at 650 degrees C (Fe3O4@C-650) displays a remarkable estimated adsorption performance (57.5 mg DBT/g for 200 ppmw), extraordinary high desulfurization efficiency (99% for 200 ppmw), and a high selectivity for DBT compared with its derivatives. Moreover, Fe3O4@C can be recovered in a quite easy, economical, and eco-friendly manner by an external magnet after five cycles without significant weight loss, which significantly simplifies the operation procedure and favors the recycle of Fe3O4@C. Combined with the economic and eco-friendly merits, Fe3O4@C offers a new avenue to employ the magnetic carbon materials for industrial applications and provides a promising substitute for adsorptive desulfurization in view of academic, industrial, and environmental aspects.