Novel magnetic g-C(3)N(4)/α-Fe(2)O(3)/Fe(3)O(4) composite for the very effective visible-light-Fenton degradation of Orange II

A novel magnetic heterogeneous g-C(3)N(4)/α-Fe(2)O(3)/Fe(3)O(4) 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-C(3)N(4)/α-Fe(2)O(3)/Fe(3)O(4) catalyst for the photo-Fenton degradation of Orange II in the presence of H(2)O(2) irradiated with visible light (λ > 420 nm) at neutral pH was evaluated. The g-C(3)N(4)/α-Fe(2)O(3)/Fe(3)O(4) 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)/H(2)O(2)). The results indicated that successfully combining monodispersed Fe(3)O(4) nanoparticles and g-C(3)N(4)/α-Fe(2)O(3) enhanced light harvesting, retarded photogenerated electron–hole recombination, and significantly enhanced the photocatalytic activity of the system. The g-C(3)N(4)/α-Fe(2)O(3)/Fe(3)O(4) (30%) sample gave the highest degradation rate constant, 0.091 min(−1), which was almost 4.01 times higher than the degradation rate constant for α-Fe(2)O(3) and 2.65 times higher than the degradation rate constant for g-C(3)N(4)/α-Fe(2)O(3) under the same conditions. A reasonable mechanism for catalysis by the g-C(3)N(4)/α-Fe(2)O(3)/Fe(3)O(4) composite was developed. The g-C(3)N(4)/α-Fe(2)O(3)/Fe(3)O(4) 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.