Synthesis and Characterization of CdS/g-C3N4/rGO Composite and Evaluation of its Photocatalytic Performance from Kinetics Perspective

In this research, CdS/g-C3N4 /rGO ternary composite was prepared by hydrothermal method and characterized using various techniques including X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and UV-Visible spectrophotometer. The photocatalytic activity of the prepared composite was evaluated from kinetics perspective by studying the removal of ciprofloxacin antibiotic under visible light. Kinetics studies based on the Langmuir-Hinshelwood model showed that the photocatalytic removal of ciprofloxacin by CdS/g-C3N4 /rGO follows the first-order kinetics model. It was found that the removal rate decreases with increasing drug concentration. In addition, by increasing the amount of catalyst from 0.1 to 0.7 gL-1, the reaction rate increases and further increase of the catalyst leads to a decrease in rate. The effect of pH showed that the photocatalytic removal rate of ciprofloxacin at neutral medium is much higher than acidic and alkaline conditions.