A systematic review on the photocatalytic efficiency of g-C3N4 based photocatalyst for antibiotic degradation under LED light irradiation

In recent years, photocatalytic processes have gained attention as one of the effective methods for removing resistant pollutants, including antibiotics. This study, conducted as a systematic review, examines the studies regarding the use of graphitic carbon nitride (g-C 3 N 4 ) based photocatalysts for the degradation of antibiotics under LED light irradiation. The process's Operational parameters were analyzed, including antibiotic concentration, photocatalyst dosage, pH, and reaction time. Factors such as light intensity, reaction kinetics, and the photocatalyst's recyclability were also investigated. Finally, 60 eligible studies were ultimately selected for this systematic review. Additionally, 56 % of the studies demonstrated antibiotic removal efficiency of over 90 %. The pH range that showed the highest efficiency was between 6 and 7. 34 % of the studies examined antibiotic concentrations in the range of 10–20 mg/L. The highest photocatalyst dosage was found in two ranges: 0.4–0.5 g/L (22 % of studies) and 0.8–1 g/L (25 % of studies). The most stable catalyst, which showed the least reduction in efficiency during reuse, exhibited only a 2.3 % decrease in efficiency from cycles 1 to 4. Overall, this review revealed that optimization of operational parameters, along with the integration of graphitic carbon nitride (g-C 3 N 4 ) into composite photocatalysts via elemental doping or structural engineering, markedly enhances antibiotic degradation performance. The distinctive band-gap characteristics of g-C 3 N 4 promote efficient visible-light harvesting and charge carrier separation, whereas LED irradiation offers a stable and energy-efficient light source ideally aligned with the photocatalytic response of g-C 3 N 4 -based systems. • 56 % of g-C₃N₄-based photocatalysts achieved >90 % antibiotic degradation under LED light, with 7.0 % reaching complete (100 %) removal. • Neutral pH (6.0–7.0) and low antibiotic concentrations (10–20 mg/L) maximized photocatalytic performance across studies. • g-C₃N₄’s visible-light absorption (2.7 eV bandgap) and composites (e.g., doping, heterojunctions) enhanced charge separation and stability. • Pseudo-first-order kinetics dominated (58 % of studies), with rate constants linked to catalyst composition and pollutant adsorption. • Limited real-scale applications despite high lab efficacy; reuse stability varied (2.3–42.7 % efficiency drop over 3.0–10 cycles).