Assessing the Degradation of Levofloxacin in Aqueous Media by Metal-Free g-C[sub.3]N[sub.4] Photocatalyst Under Simulated Solar Light Irradiation

Graphitic carbon nitride (g-C[sub.3]N[sub.4]) as a fascinating conjugated polymer has attracted considerable attention due to its outstanding electronic properties, high physicochemical stability, and unique structure. In this work, we reported the characterization of g-C[sub.3]N[sub.4], which was simply synthesized by thermal polymerization of thiourea, the photocatalytic degradation kinetics, and the pathway of levofloxacin (LEV) using the prepared g-C[sub.3]N[sub.4]. The XRD and SEM results confirmed a crystalline graphite structure with a tri-s-triazine unit and stacked sheet-like layers of g-C[sub.3]N[sub.4]. The efficacy factor (EF) was compared to different photocatalytic processes to assess the LEV removal performance. g-C[sub.3]N[sub.4] exhibits good stability as a photocatalyst during LEV photodegradation. Radical scavenger experiments revealed that in the oxidative degradation of LEV, [sup.•]O[sub.2] [sup.–] and h[sup.+] played the determining roles. Moreover, based on the identification of intermediates using liquid chromatography with tandem mass spectrometry (LC-MS/MS), the degradation pathway of LEV was proposed.