Synthesis and evaluation of the performance of g-C3N4/Fe3O4/Ag photocatalyst for the efficient removal of diazinon: Kinetic studies

Herein, a well-known pesticide named diazinon was successfully removed from aqueous solutions by the UV photocatalytic process in which g-C3N4/Fe3O4/Ag was applied as a nanocomposite. Initially, g-C3N4/Fe3O4/Ag nanocomposite was synthesized by a hydrothermal method and XRD, FT-IR, SEM, EDX and PL analyses were employed to identify the nanocomposite structure. The best conditions for the complete removal of diazinon (DZN) (i.e., 100 %) were obtained after 60 min under the following conditions: pH = 7, catalyst dosage of 0.5 g/ L and DZN concentration of 5 mg/L. The removal reaction followed the first order kinetic model (k, 0.067; R-2, 0.9982). Furthermore, the effects of several scavengers such as ammonium oxalate (AO), tert-butanol (TB) and benzoquinone (BQ) on the performance of the removal reaction were investigated revealing that the hydroxyl ions played an active role in the reaction. Finally, the photocatalytic process using the nanocomposite g-C3N4/Fe3O4/Ag proved to be promising for the removal of DZN pesticide from aqueous media.