Enhanced photodegradation of ciprofloxacin with organic photocatalyst through a ternary strategy

Antibiotics, as emerging organic pollutants, have seriously affected the biodiversity of water and threatened mankind’s health. Currently, low charge separation efficiency and insufficient light utilization limit the application of traditional photocatalysts in antibiotic degradation. In this work, the organic photovoltaic material PM6: Y6 was incorporated into an organic photocatalyst with bulk-heterojunction, and a third component, 3,9-bis{2-methylene-[3-(1,1-dicyanomethylene)-cyclopentane-1,3-dione-(c)thiophen]}-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2’,3’-d’]-s-indaceno[1,2-b:5,6-b’]dithiophene (ITCPTC), was added to adjust the absorption spectrum of photocatalyst for efficient photodegradation of ciprofloxacin (CIP). Benefiting from excellent light utilization and effective carrier separation and transfer, the catalyst exhibited excellent photocatalytic performance, achieving a 90%/99% degradation rate of CIP within 30/60 min under simulated sunlight irradiation (~79 mW/cm2). Besides, the catalyst still exhibited good photocatalytic performance after multiple cycles of use. By Electron Spin Resonance analysis, the active species for photocatalytic degradation of CIP were mainly holes (h+) and superoxide radicals (·O2-). Designing photocatalysts with a wider light absorption range and better charge separation is a feasible idea to achieve better photocatalytic performance. It is anticipated that this work could enhance the understanding of modification strategies for ternary organic semiconductors and expand the application of photocatalysis in environmental pollution control and remediation.