Fe3O4-Loaded g-C3N4/C-Layered Composite as a Ternary Photocatalyst for Tetracycline Degradation

A ternary photocatalyst, Fe3O4-loaded g-C3N4/C-layered composite (g-C3N4/C/Fe3O4) was fabricated by a facile sonication and in situ precipitation technique. Carbon nanosheets were prepared using the remaining non-metallic components of waste printed circuit boards as carbon sources. In this hybrid structure, g-C3N4 was immobilized on the surfaces of carbon nanosheets to form a layered composite, and 10–15 nm Fe3O4 nanoparticles are uniformly deposited on the surface of the composite material. The photocatalytic performance of the catalyst was studied by degrading tetracycline (TC) under simulated sunlight. The results showed that the photoactivity of the g-C3N4/C/Fe3O4 composite to TC was significantly enhanced, and the degradation rate was 10.07 times higher than that of pure g-C3N4, which was attributed to Fe3O4 nanoparticles and carbon nanosheets. Carbon sheets with good conductivity are an excellent electron transporter, which promotes the separation of photogenerated carriers and the Fe3O4 nanoparticles can utilize electrons effectively as a center of oxidation–reduction. Moreover, a possible photocatalytic mechanism for the excellent photocatalytic performance was proposed.