Magnetically Separable Mesoporous Fe3O4@g-C3N4 As a Multifunctional Material for Metallic Ion Adsorption, Oil Removal from the Aqueous Phase, Photocatalysis, and Efficient Synergistic Photoactivated Fenton Reaction

Water pollution is a global problem. Therefore, efficient methods for oil/water separation, degradation of organic dyes, and adsorption of metal ions from wastewater are urgently needed for environmental protection. Herein, mesoporous g-C3N4, nanosized Fe3O4, and aminopropyl triethoxysilane were used as raw materials to assemble a multifunctional magnetic water purification material (MPG-C3N4/Fe3O4/NH2). The homogeneously dispersed Fe3O4 particles and hydrophobic hydrocarbon chain on the surface endows it with excellent magnetic oil/water separation properties even after 10 cycles. MPG-C3N4/Fe3O4/NH2 possesses prominent adsorption capacity of as high as 93.45 mg/g for metallic ions Cu2+. The adsorption of Cu2+ on MPG-C3N4/Fe3O4/NH2 is in accordance with the second-order kinetic model and the Langmuir monolayer adsorption model. Notably, MPG-C3N4/Fe3O4/NH2 can degrade organic pollutants because of its photocatalytic ability due to the heterojunction formation between MPG-C3N4 and Fe3O4 nanoparticles. The hydrophobic surface allows more oxygen to enter the heterogeneous degradation system, improving the efficiency of O-2 to receive photogenerated electrons to convert into O-2(center dot-). Surprisingly, MPG-C3N4/Fe3O4/NH2 can be used as a heterogeneous photoactivated Fenton catalyst with brilliant degradation rates and efficiency (as high as 95% within 40 min) toward complicated organic pollutants, for example, RhB, phenol, and BPA with favorable reusability.