Recoverable magnetic CoFe2O4/BiOI nanofibers for efficient visible light photocatalysis

A facile methodology for fabricating novel magnetic fibrous visible light photocatalysts CoFe2O4/BiOI (CFO/BiOI) is presented. The fabrication procedure involves production of electrospun CoFe2O4 nanofibers and subsequent controllable decoration of BiOI nanoplates by both the successive ionic layer adsorption and reaction (SILAR) and solvothermal methods on CoFe2O4 nanofiber surface. The BiOI nanoplates on the fiber surface obtained by two methods are highly crystallized with lamellae morphology. The resulting CFO/BiOI fibers exhibit strongly magnetic response to external magnetic field and can be quickly collected. All the CFO/BiOI fiber samples exhibit excellent visible light photocatalytic performance towards degrading RhB regardless of the preparation methods, in which h+ and O2− play the major roles examined by the trapping experiment. Above 80% RhB dyes can be degraded within 2 h after 3 cycles under visible light irradiation, suggesting the good reusability of the photocatalysts. This work demonstrates that the CFO/BiOI is characteristic with high visible light photocatalysis performance and magnetic response, hence is promising for photocatalysis.