Facile synthesis of magnetic mesoporous silica spheres by a sol-gel/surface-protected etching/incipient wetness impregnation approach

Abstract

We recently synthesized the magnetic mesoporous silica spheres (MMSS) by a sol-gel/surface-protected etching/incipient wetness impregnation approach. Silica spheres (SS) were firstly synthesized by the Stöber method, and surface-protected etching allowed convenient conversion of sol-gel derived silica into mesoporous structures (mesoporous silica spheres, MSS). The immobilization of magnetic nanoparticles over MSS supports was addressed by incipient wetness impregnation. XRD, TEM, and nitrogen sorption technique showed successful synthesis as desired. The iron loadings could reach to 32.67 wt% and narrow pore size distribution centered at ca. 4 nm was found. MMSS exhibits superior persulfate (PDS) activation as well as stability for removing the organic compounds. In addition, magnetic separation of the materials offers great prospects for fast and economical reuse.