Novel magnetic g-CN/α-FeO/FeO composite for the very effective visible-light-Fenton degradation of Orange II.

A novel magnetic heterogeneous g-CN/α-FeO/FeO catalyst was successfully synthesized through a simple hydrothermal method. The structure, morphology, and optical properties of the catalyst were characterized. The photocatalytic activity of the heterogeneous g-CN/α-FeO/FeO catalyst for the photo-Fenton degradation of Orange II in the presence of HO irradiated with visible light ( > 420 nm) at neutral pH was evaluated. The g-CN/α-FeO/FeO photocatalyst was found to be an excellent catalyst for the degradation of Orange II and offers great advantages over the traditional Fenton system (Fe(ii/iii)/HO). The results indicated that successfully combining monodispersed FeO nanoparticles and g-CN/α-FeO enhanced light harvesting, retarded photogenerated electron-hole recombination, and significantly enhanced the photocatalytic activity of the system. The g-CN/α-FeO/FeO (30%) sample gave the highest degradation rate constant, 0.091 min, which was almost 4.01 times higher than the degradation rate constant for α-FeO and 2.65 times higher than the degradation rate constant for g-CN/α-FeO under the same conditions. A reasonable mechanism for catalysis by the g-CN/α-FeO/FeO composite was developed. The g-CN/α-FeO/FeO composite was found to be stable and recyclable, meaning it has great potential for use as a photo-Fenton catalyst for effectively degrading organic pollutants in wastewater.