Mesoporous Functionalized g-C3N4 with Magnetic Properties for Adsorption of Tetracycline from Water

Tetracycline (TC) antibiotic with high water solubility and a long environmental half-life is extensively used in human and veterinary medicine. In this study, graphitic carbon nitride (g-C3N4) was functionalized with hydrophobic 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane and was used for the adsorption of TC antibiotic. The synthesized adsorbent was characterized by using, XRD, SEM and VSM. The perfluorinated and magnetic g-C3N4 (PMCN) with hydrophobic property floated on the surface of solution and separated easily by using magnetic force. The adsorption capacity of PMCN towards TC was enhanced by about ten times compared to bare g-C3N4, and reached 222.2 mg/g. In the equilibrium adsorption test, three adsorption isotherm models, namely the Freundlich, Langmuir and BET were investigated, and data for the adsorption of TC on bare g-C3N4 and PMCN showed the best fit to the BET model. Three models, including, pseudo-first-order, pseudo-second-order and intra-particle diffusion were used to explain the adsorption kinetics. The adsorption of TC on both adsorbents followed the pseudo-second-order kinetic model. As a result of potential photocatalytic activity of g-C3N4, the developed modified bifunctional adsorbent/photocatalyst can be used for the adsorption and subsequent photocatalytic degradation of hazardous organic contaminates such as TC.

Keywords:

Adsorption , g-C3N4 , Tetracycline , Magnetic , Antibiotic , Functionalized adsorbent