Photocatalytic degradation of tetracycline by g-C3N4/stilbite under visible light: Mechanistic insights and degradation pathways

• g-C 3 N 4 /stilbite was successfully fabricated by the in-situ synthesis method. • g-C 3 N 4 /stilbite composite exhibited the outstanding TC degradation performance. • h + and •O 2 − were mainly responsible for TC degradation under visible light. In this study, the g-C 3 N 4 /stilbite composite was fabricated by the in-situ synthesis method, and the photocatalytic performance was investigated by degrading tetracycline (TC) under visible light. The results indicated that the photocatalytic degradation efficiency of g-C 3 N 4 /stilbite-6 (86.8 %) was about 2.7 times higher than that of pure g-C 3 N 4 (31.8 %). The introduction of the stilbite carrier effectively resolved the issues of g-C 3 N 4 such as easy self-agglomeration and the difficulty in separating photo-generated carriers, thereby improving the photocatalytic activity of g-C 3 N 4 . From the quenching experiment, it was found that h + and •O 2 − were main active species for TC degradation. By HPLC-MS analysis, TC degradation products were identified, and three degradation pathways were proposed. In addition, the impacts of solution pH, light intensity, and catalyst dosage on TC degradation performance were also evaluated. Overall, a simple and successful strategy has been proposed to synthesize high-performing visible-light-driven photocatalysts for efficiently eliminating organic contaminants from wastewater.