Synthesis and photocatalytic properties of magnetic separable and recyclable p-n heterojunction CoFe2O4/Bi12O17Cl2 photocatalyst

A series of CoFe2O4/Bi12O17Cl2 (CFO/Bi12O17Cl2) nanocomposites have been prepared by the chemical precipitation method. The result of X-ray diffraction showed that CFO/Bi12O17Cl2 composites had high crystallinity. It was found that CoFe2O4 particles were well supported on the Bi12O17Cl2 sheet as observed using a scanning electron microscope and transmission electron microscope. The UV-vis diffuse reflectance spectra showed that CFO/Bi12O17Cl2 composites had excellent visible light response-ability. The results of the experiment showed that the weight percentage of CoFe2O4 in CFO/Bi12O17Cl2 composites had a great influence on the degradation of rhodamine B upon visible-light illumination. The photocatalytic properties for degrading rhodamine B of CFO/Bi12O17Cl2 composites were enhanced compared to bare Bi12O17Cl2, and when the loading mass ratio of CoFe2O4 was 3%, the CFO/Bi12O17Cl2 composite showed the best photocatalytic activity. It had nice reusability and magnetic circulation. Superoxide radicals and holes were the major active factors in the photocatalytic process. Moreover, the composite can be easily solid–liquid separated under an external magnetic field, which shows that CFO/Bi12O17Cl2 composites possess great potential for the use of solar energy to degrade various dye pollutants.