Novel Co-doped Fe3O4/Bi2WO6 core–shell magnetic photocatalysts with enhanced photocatalytic degradation of contaminants

Novel Co-doped Bi2WO6 nanosheets on the surfaces of an Fe3O4 hybrid material were synthesized by a facile hydrothermal method. The samples were systematically characterized by multiple techniques including XRD, SEM, TEM, UV-vis diffuse reflectance spectroscopy, PL, and SQUID magnetometry. The photocatalytic activity of the obtained samples was evaluated by using rhodamine B (RhB) as a target organic pollutant. The results indicated that 1%Co2+-Fe3O4(0.04 g)/Bi2WO6 displayed the highest photocatalytic activity, and the degradation efficiency reached 88.8% after 120 min. More importantly, the 1%Co2+-Fe3O4(0.04 g)/Bi2WO6 hybrid material showed good magnetic properties, and it could be effectively separated from the reaction mixture by applying an external magnetic field. The enhanced photocatalytic activity should be attributed to the synergistic effect between the heterojunction interface and the Co2+ doping effect, which leads to a strong visible light absorption and higher migration efficiency of photogenerated electron-hole pairs. 1%Co2+-Fe3O4/Bi2WO6 is expected to be a promising photocatalyst for environmental cleaning.