Singlet oxygen mediated Fe2+/peroxymonosulfate photo-Fenton-like reaction driven by inverse opal WO3 with enhanced photogenerated charges

Singlet oxygen (O-1(2)) as an important reactive oxygen species (ROS) has broad application prospects in the fields of organic synthesis, cell repair, environmental remediation et al. However, the mechanism of the O-1(2) formation in the Fe2+/PMS Fenton-like system, which is directly transformed from .O2- or generated by .OH as an intermediate, is still a mystery. Herein, we designed an inverse opal WO3 (IO WO3) co-catalytic photo-Fenton-like system, which can finish RhB (20 mg.L-1) degradation within 6 min. And the optimal condition of pH, light intensity, FeSO4.7H(2)O dosage, PMS dosage, cocatalyst dosage were also explored in this work. The highefficiency photogenerated long lifetime charge carriers produced by IO WO3 cocatalyst under photocatalytic process can directly make a conversion from SO4.(-) and .O-2(-) to O-1(2) without .OH intermediate in the solution. Furthermore, the IO WO3 cocatalyst addition can improve the reduction of Fe3+/Fe2+ ions to enhance activation of PMS molecule. As for the interconnected periodic macroporous framework of inverse opal WO3 would help to improve mass transfer and light harvest in the photo-Fenton-like process. This facile synthesized material with recyclable and stable co-catalytic activity for the contaminant remediation, and the selective generation of O-1(2) in the Fe2+/PMS process, will highlight its huge application in environmental potential.