Novel Co-doped Fe 3 O 4 /Bi 2 WO 6 core–shell magnetic photocatalysts with enhanced photocatalytic degradation of contaminants

Novel Co-doped Bi 2 WO 6 nanosheets on the surfaces of an Fe 3 O 4 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%Co 2+ -Fe 3 O 4 (0.04 g)/Bi 2 WO 6 displayed the highest photocatalytic activity, and the degradation efficiency reached 88.8% after 120 min. More importantly, the 1%Co 2+ -Fe 3 O 4 (0.04 g)/Bi 2 WO 6 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 Co 2+ doping effect, which leads to a strong visible light absorption and higher migration efficiency of photogenerated electron–hole pairs. 1%Co 2+ -Fe 3 O 4 /Bi 2 WO 6 is expected to be a promising photocatalyst for environmental cleaning.