Synthesis and characterization of g-C3N4 doped with activated carbon (AC) prepared from grape leaf litters for the photocatalytic degradation of enrofloxacin in aqueous systems

Abstract

The composites of graphitic carbon nitride (g-C3N4) doped with activated carbon (AC) were synthesized using the calcination method, and used as photocatalysts for the degradation of enrofloxacin in an aqueous system. The physical, morphology, and spectroscopic properties of the synthesized AC, bulk g-C3N4, and AC/g-C3N4 composites were characterized using x-ray diffraction spectroscopy (XRD), Fourier transforms infrared spectroscopy (FTIR), Brunauer-Emmett-Teller method (BET), scanning electron microscopy, energy dispersive x-ray mapping (SEM-EDX-mapping), transmission electron microscopy (TEM) with high resolution-transmission electron microscopy (HR-TEM), ultraviolet-visible diffuse reflectance spectroscopy techniques (UV-Vis DRS), photoluminescence spectroscopy (PL), and electron impedance spectroscopy (EIS). The AC/g-C3N4 composites exhibited an extended visible light response and higher separation rate of photogenerated electron-hole pairs compared to the bulk g-C3N4. The 1 : 1AC/g-C3N4 composite showed superior photocatalytic performance, nearly seven times higher than the bulk g-C3N4 nanosheets, toward the degradation of enrofloxacin in aqueous solutions, under visible light irradiation. The high photocatalytic efficiency of AC/g-C3N4 composites may be attributed to the role played by the significantly improved surface area, and the occurrence of high photoinduced charge separation, as revealed by the morphological and opto-spectroscopic characterization of the synthesized composites, and photocatalysis experimental data. Furthermore, the AC/g-C3N4 composites exhibited excellent recyclability and stability, making them potential candidates for use in environmental remediation.