Synthesis and photocatalytic properties of magnetically separable and recyclable p–n heterojunction CoFe2O4/Bi12O17Cl2 photocatalyst

Abstract

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.