Magnetic amphiphilic nanocomposites based on silica–carbon for sulphur contaminant oxidation

Abstract

Silica and carbon based magnetic amphiphilic nanocomposites (MANCs) were synthesized and applied for desulfurization in this work. The structure, composition, and magnetic and amphiphilic properties of the resulting MANCs were characterized in detail by physicochemical means such as XRD, elemental analysis, Raman spectroscopy, electron microscopies, thermal analysis, TPR, Mössbauer spectroscopy, magnetization measurements, and contact angle measurements. Different concentrations of Fe and Mo were supported on the surface of silica in order to catalyse the controlled growth of carbon nanotubes and nanofibers by chemical vapor deposition (CVD). The partial coating of hydrophilic silica with hydrophobic carbon nanostructures imparts amphiphilicity, which makes the composites strategic catalysts to promote emulsion formation and to act on the interface. Moreover, during the CVD process magnetic species were produced conferring magnetic properties which can facilitate the emulsion breakage by a simple magnetic process. Studies on desulfurization reactions catalysed by these nanocomposites were promising and showed that Mo plays an important role in the catalyst efficiency.