Synergistic Effect of g‐C ₃ N ₄ –Based Binary Composites for the Photocatalytic Degradation of Model Organic Pollutants

ABSTRACT In this work, binary composites of graphitic carbon nitride (g‐C 3 N 4 ) with iron oxide (Fe 2 O 3 ) and zinc oxide (ZnO), namely GF4 and GZ4, were synthesized via cost‐effective and environmentally friendly methods. The composites showed enhanced specific surface area and improved charge carrier separation compared to the bare g‐C 3 N 4 , Fe 2 O 3 , and ZnO. The photocatalytic activity of the binary composites was evaluated based on the degradation of model organic pollutants, methyl orange (MO) and caffeine, under UV and visible light irradiation. Under 120 min UV light irradiation, the most efficient GZ4 and GF4 composites achieved 97% degradation of MO. Meanwhile, under similar condition, the GF4 and GZ4 composites showed a much lower degradation efficiency toward caffeine, 47% and 64%, respectively. Interestingly, the binary composites exhibited a 26‐fold increase in MO degradation under visible light compared to bare g‐C 3 N 4 due to a synergistic effect. Total organic carbon (TOC) analysis revealed 58% mineralization of caffeine under UV light, indicating the potential of these materials for effective wastewater treatment. The obtained photocatalysts displayed excellent stability and reusability, suggesting their practical use for the remediation of our environment.