Mesoporous silica-coated superparamagnetic magnetite functionalized with CuO and its application as a desulfurizer

Well-dispersed superparamagnetic nanocomposites, mesoporous silica-coated nano-sized magnetite (MSNSM) as a magnetic carrier and CuO-coated MSNSM (CuO-MSNSM) as a new desulfurizer have been reported. The MSNSM, prepared via a nano-assembling method by using cationic surfactants as templates, consists of a 12-nm-in-diameter core of magnetite particle and about 4-nm-thickness shell of mesoporous silica (MS), and shows high specific surface area (ca. 154 m2/g). The CuO-MSNSM was obtained by immersing the MSNSM into a copper solution, which formed a nano-scaled particle of CuO onto the surface of MSNSM upon followed calcination. The results revealed that both MSNSM and CuO-MSNSM exhibit strongly superparamagnetic properties with saturation magnetization values (Ms) of over 28 emu/g. Both would be potential functional magnetic carriers. As an example of its wide applications, the CuO-MSNSM was tested as a desulfurizer. It was found that the CuO-MSNSM is an excellent organic sulfur adsorber, performing fully separation of the organic sulfur in a model dodecanethiol-added petroleum liquid.