One-step synthesis of iron and carbon-quantum-dot co-decorated graphitic carbon nitride photocatalysts for carbamazepine degradation

In this study, a one-step hydrothermal preparation strategy was employed to synthesize a graphitic carbon nitride (g-C3N4) composite photocatalyst co-decorated with Fe sites and carbon quantum dots (Fe-CQDs/g-C3N4). Through a series of characterisation techniques, the successful integration of Fe atoms and carbon quantum dots (CQDs) onto g-C3N4 was achieved. Moreover, the presence of Fe, specifically Fe-N bonds, enhanced the charge- carrier transfer. With carbamazepine (CBZ) as the model pollutant, Fe-CQDs/g-C3N4 increased the photocatalytic activity with efficient peroxymonosulfate (PMS) activation under solar light irradiation, achieving 100 % CBZ degradation in 15 min over a wide pH range (3-9). Doping of the catalyst with Fe and CQDs resulted in a narrowing of the catalyst bandgap (2.25 eV) compared to that of g-C3N4 (2.79 eV), confirming the promotion of photo-induced charge separation. The CBZ degradation pathways were elucidated by ultrahigh-performance liquid chromatography and high-definition mass spectrometry. The Fe-CQDs/g-C3N4 composite was found to possess substantial potential for the efficient degradation of pollutants.