Enhancement of peroxymonosulfate activation and utilization efficiency via iron oxychloride nanosheets in visible light

Inspired by the photosensitivity and self-heal properties of iron oxychloride (FeOCl), we used photocatalysis coupling peroxymonosulfate (PMS) activation for effective aquatic decontamination in a cost-efficient and environmentally friendly method. Synthesized FeOCl was appointed to activate PMS to degrade bisphenol A (BPA, 2,2-bis(4-hydroxydiphenyl) propane) persistently under visible light. The best performance of FeOCl/PMS/Vis system was similar to 100% BPA degradation efficiency which achieved in 20 min. The BPA removal efficiency had a positive correlation with the dosages of FeOCl and PMS, but negatively related to EPA concentration. The FeOCl/PMS/Vis system also presented impressive degradation performance at a wide pH range (pH = 3-11) and showed well excellent stability and reusability. The addition of either bicarbonate or chloride had impressive promotion effect on BPA removal. The reaction mechanism of FeOCl/PMS/Vis system was studied deeply. PMS was activated to generate active radicals (SO4 center dot- and HO center dot) by Fe(II) of FeOCl for EPA degradation. Then the as formed Fe(III) was reduced to Fe(II) via trapping photoexcited electrons in conduction band (CB) of FeOCl, which effectively inhibited the recombination of photo-generate charges and the pollutants oxidation would recur via facilitating the Fe(II)/Fe(III) redox recycle. Thus, the activation and utilization efficiency of PMS was effectively improved. This work indicated the FeOCl/PMS/Vis system was a promising application in wastewater treatment.