Double heterojunction CQDs/CeO2/BaFe12O19 magnetic separation photocatalysts: Construction, structural characterization, dye and POPs removal, and the interrelationships between magnetism and photocatalysis
Shifa Wang, Xiangyu Chen, Leiming Fang, Huajing Gao, Mengjun Han, Xiping Chen, Yuanhua Xia, Lei Xie, Hua Gui Yang
Abstract
This novel double heterojunction carbon quantum dots (CQDs)/CeO2/BaFe12O19 magnetic separation photocatalysts (CCBFOMSPs) were successfully prepared via a polyacrylamide gel method and low temperature sintering technology combined with a hydrothermal method. The CQDs components in CCBFOMSPs were identified by neutron powder diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy. The charge carriers could transfer and separation between the valence state components (CeO2 and BaFe12O19) and CQDs facilely, inhibiting the recombination of electron-hole pairs significantly by Hall effect. The photocatalytic activity of CCBFOMSPs for the degradation of mixed dyes include methyl orange (MO), rhodamine B (RhB) and methylene blue (MB) and tetrabromobisphenol A (TBBPA) were remarkably improved by regulating the electromagnetic interaction between the BaFe12O19 contents and the photo-generated electrons. Capturing experiment showed that the active species of hole (hVB+), hydroxyl radical (•OH) and superoxide radical (•O2−) played dominant roles in mixed dyes degradation. Attractively, the effect shed new light on wide applications of the double heterojunction magnetic separation photocatalysts.