Ordered mesoporous carbon-silica frameworks confined magnetic mesoporous TiO2 as an efficient catalyst under acoustic cavitation energy

Abstract

Herein, we report a biphase stratification strategy that enables the encapsulation of magnetic mesoporous TiO2 inside an ordered mesoporous C/SiO2 framework. The obtained composites exhibit high surface areas (up to 600 m2 g−1), large perpendicular pore sizes (up to 9 nm) and a strong magnetic response (∼10.0 emu g−1), presenting significantly enhanced degradation activities toward pentachlorophenol (PCP) and bisphenol-A (BPA) under acoustic cavitation energy. The remarkable performance is ascribed to the synergistic effect from the unique structural modulation: 1) The large ordered mesopores favors the mass transfer, 2) The mesoporous C/SiO2 frameworks promote the adsorption of organic pollutants and enrich them close to the TiO2 surface and 3) The special spatial arrangement of different components facilitates the generation of cavitation bubbles, leading to the increase in the overall hydroxyl-radical-production rate. Moreover, owing to the effective confinement, the as-prepared materials possess an excellent stability and durability. More importantly, the catalysts can easily be recovered by a magnet and show an excellent reusability. It is believed that these results could provide an important insight for the development of an efficient, stable and facile recoverable catalyst for the acoustic chemical process. Keywords: Fe3O4@mTiO2@mC/SiO2, Acoustic cavitation, Magnetic separation, Mechanical stability