Evaluation of non-metal doped graphitic carbon nitride for photocatalytic degradation of antibiotic: Insights from oxygen doping

The contamination of water resources with antibiotic residues poses significant environmental and public health risks. This study explores the photocatalytic degradation of antibiotics, with a focus on improving the efficiency of graphitic carbon nitride (g-C3N4) through non-metal doping. Pristine g-C3N4 was synthesized via thermal polymerization of urea, while oxygen (O)-doped g-C3N4, with narrower band gaps, was prepared using a one-pot synthesis method. SEM and EDX analysis confirmed the successful increase in oxygen content due to doping. The photocatalytic performance was evaluated through the degradation of Oxytetracycline (OTC) under LED light. Interestingly, pristine g-C3N4 demonstrated higher removal efficiency of OTC compared to O-doped g-C3N4. The degradation efficiency followed the trend: 5 ppm > 30 ppm > 10 ppm, with pristine g-C3N4 showing superior performance across all concentrations. This outcome is attributed to lower recombination rates and greater active site availability in the pristine material. Kinetic analysis showed that both photocatalysts followed a first-order kinetic model, with higher degradation rates observed at lower OTC concentrations. This study underscores the potential of g-C3N4 in antibiotic degradation, highlighting the need for further optimization of photocatalyst properties to enhance water treatment technologies. © 2025 Institute of Physics Publishing. All rights reserved.