Magnetic 3-D ordered macroporous silica templated from binary colloidal crystals and its application for effective removal of microcystin

Magnetic 3-D ordered macroporous siliceous materials were conveniently fabricated by combination of a simple co-sedimentation of binary colloidal system of PMMA spheres and magnetite nanoparticles and the infiltration of silica precursors. The SEM and TEM observations indicate that the obtained magnetic 3-D ordered macroporous silica materials have face-centered cubic (fcc) packing structure with ordered macropore of ∼200 nm and interconnected windows of about 50 nm. Magnetic property characterization shows that the magnetic 3-D ordered macroporous silica materials possess high magnetization (19.2 emu/g) and superparamagentism. By utilization of their ordered macroporous structure with large entrances and good affinity for biomacromolecules as well as high magnetization, a fast and efficient removal of microcystin in water with high removal efficiency (>93%) and removal capacity (3.3 ng MC/mg) was achieved with the help of an applied magnetic field.