Charge Transport and Heavy Metal Removal Efficacy of Graphitic Carbon Nitride Doped with CeO2

Doping of graphitic carbon nitride (g-C3N4) with semiconductors prevents electron-hole recombination and enhances adsorption capacity. This work investigates the synthesis of a water remediation material using g-C3N4 doped with CeO2 using two different techniques. The chemical structures of the doped g-C3N4 samples were confirmed using FTIR, XRD, XPS and their morphology was studied using SEM-EDX. Charge transport through the doped materials was illustrated by a comprehensive dielectric study using broadband spectroscopy. The ability of doped g-C3N4 to adsorb heavy metals was investigated thoroughly in the light of applying different parameters such as temperature, pH, time, and concentration. The results showed that the mode of doping of g-C3N4 by CeO2 strongly affected its adsorption capacity. However, g-C3N4 doped with CeO2 using the first mode adsorbed 998.4 mg g-1 in case of Pb2+ and 448 for Cd2+. Kinetic study revealed that the adsorption process obeyed PSORE as its q exp e is close to its q cal e and the rate-controlling step involved coordination among the synthetic materials and the heavy metal ions. The recovery of Pb2+ and Cd2+ ions from various sorbents was investigated by utilizing different molar concentrations of HNO3 and indicated no significant change in the sorption capability after three different runs. This study has demonstrated an efficient method to obtain a highly efficient adsorbent for removing heavy metals from waste water.