Interface Assembly to Magnetic Mesoporous Organosilica Microspheres with Tunable Surface Roughness as Advanced Catalyst Carriers and Adsorbents

Surface roughness endows microspheres with unique and useful features and properties like improved hydrophobicity, enhanced adhesion, improved stability at the oil–water interface, and superior cell uptake properties, thus expanding their applications. Core–shell magnetic mesoporous microspheres combine the advantages of magnetic particles and mesoporous materials and have exhibited wide applications in adsorption, catalysis, separation, and drug delivery. In this study, virus-like rough core–shell–shell-structured magnetic mesoporous organosilica (denoted as RMMOS) microspheres with controllable surface roughness were successfully obtained through electrostatic interaction-directed interface co-assembly. The obtained RMMOS microspheres possess uniform spherical morphology with tunable surface roughness, radially aligned pore channels with a diameter of 3.0 nm in the outer organosilica shell, high specific surface area (396 m2/g), large pore volume (0.66 cm3/g), high magnetization (35.1 emu/g), and superparamagnetic property. The RMMOS microspheres serve as desirable candidates to support Au nanoparticles (2.5 nm) and show superior catalytic activity and excellent stability in hydrogenation of 4-nitrophenol. In addition, the RMMOS microspheres modified with carboxylic groups further displayed promising performance in convenient adsorption removal of dyes in polluted water.