Efficient g-C3N4/rGO as a Photo-Electro-Catalyst in a Metal-Free Electro-Fenton Process for the Removal of Levofloxacin

Emerging pollutants significantly impact various ecosystems due to their complex composition, poor biodegradability, and high toxicity. There are several methods for removing these pollutions like advanced oxidation processes, Photo catalyst, and electro chemical processes. The electro-Fenton process combines the advantages of electrochemical and advanced oxidation processes. However, issues such as residual iron remain problematic. In this project, a composite catalyst of g-C3N4 and rGO, which is completely organic, metal-free, efficient, economical, and green, was utilized as a catalyst in a photo-electro-Fenton-like process to remove the antibiotic levofloxacin. The optimal conditions of this process, including current densitye, pH, aeration rat, concentration, and composition of the catalyst, were investigated and the optimum amounts of them are 50 mA/cm2, 4 ,400 ml/min ,120 mg/l and g-C3N4/rGO-1 composite respectively. The performance of the synthesized catalyst was compared with that of pure g-C3N4 in the process. The electro-Fenton process without light exposure and the photocatalyst process were also compared with this process under optimal conditions. The results demonstrated that the synergistic effect of these processes enhanced levofloxacin removal, achieving a removal percentage of 87% within 90 minutes. The stability of the catalyst was evaluated over four consecutive cycles, showing only a 15% decrease in removal efficiency during the fourth cycle. Additionally, the kinetics of reactions at different conditions were studied, and the reaction rate constants were calculated at a constant temperature.