Facile synthesis of exfoliated graphitic carbon nitride for photocatalytic degradation of ciprofloxacin under solar irradiation

Exfoliated g-C₃N₄ nanoparticles prepared by a green route (an aqueous bi-thermal method) were characterized by techniques such as XRD, UV-VDRS, FESEM, PL, TEM. Degradation of an aqueous solution of ciprofloxacin (CPN), when exposed to solar irradiation in the presence of g-C₃N₄ nanoparticles, was studied to evaluate the photocatalytic activities of semiconductor photocatalyst. The photocatalytic activities of g-C₃N₄ have enhanced after its exfoliation. The exfoliated g-C₃N₄ obtained with the aqueous bi-thermal method provided about three times the large surface area and about two and half times effective photocatalyst as bulk g-C₃N₄. The results of electrochemical tests like linear sweep voltammetry, MS graphs of exfoliated g-C₃N₄ nanoparticles together with electrochemical impendence (EIS) corroborated the results of photocatalytic activities of g-C₃N₄ after exfoliation. The enhanced photocatalytic behavior of exfoliated g-C₃N₄ is the result of its efficient separation, low recombination of photogenerated charge carriers and high surface area. The effects of exfoliated g-C₃N₄ catalyst concentration, irradiation time and initial CPN concentration on the degradation of CPN were carefully studied. We found that 1 g/L nano-exfoliated g-C₃N₄ can degrade up to 78% a 20 ppm CPN solution exposed to solar light for 1 h. The studies also incorporated scavenger tests to possibly identify reactive species and mechanism for CPN degradation. This work provided a new method for scalable exfoliation of g-C₃N₄.