Enhanced photocatalytic degradation of tri-chlorophenol by Fe3O4@TiO2@Au photocatalyst under visible-light

Heterogeneous Fe3O4@TiO2@Au core-shell microspheres, a facile and highly efficient catalyst have been fabricated by a simple surface modification. The fabrication process involved the coating of TiO2 nanoshell onto the magnetic core using by sol-gel process, and then the anchoring of Au nanoparticles onto the surface of the Fe3O4@TiO2 microspheres through the wet chemical reaction of 3-aminopropyltriethoxysilane (APTES). The as-synthesized Fe3O4@TiO2 microspheres exhibited a narrow size distribution, with a typical size of 350 nm and shell thickness of 25 nm. The Fe3O4@TiO2@Au microspheres can be easily collected by applying external magnetic field due to the magnetic property of core Fe3O4 particles. Compared to unmodified Fe3O4@TiO2 microspheres, the Fe3O4@TiO2 @Au microspheres showed higher photocatalytic activity for 2, 4, 6-trichlorophenol (TCP). The photocatalytic efficiency of the Fe3O4@TiO2 microspheres was 28% after 40 min irradiation while, the efficiency of Fe3O4@TiO2@Au microspheres was 98% at the same condition.