Mesoporous metal oxide/silica composites with photocatalytic activity and magnetic response

In this work, a novel class of mesoporous metal oxide/silica composites was prepared. Both ZnO and magnetite (Fe₃O₄) nanoparticles were embedded within the mesoporous silica architecture. The solids display a high surface area, narrow pore size distribution and a regular array of mesoporous hexagonal channels with long range ordering. All the materials were tested for the photodegradation of Rhodamine B and the catalytic performance compared with analogous mesoporous solids exclusively bearing ZnO nanoparticles in the silica framework. All the materials present good photocatalytic performance and magnetic response. The best catalyst containing 15 wt% ZnO and 5 wt% Fe₃O₄ particle loading, displays a higher turnover number than unstructured ZnO nanoparticles and commercial ZnO nanopowder and can be easily separated from the reaction mixture by simply applying a magnetic field as weak as the one generated by a common magnetic stirring bar.