Photocatalytic performance of Cd(II)-based coordination polymer of efficient antibiotic degradation

Antibiotics in water sources pose significant environmental risks and contribute to the emergence of antibiotic-resistant genes, removal is quite important but challenging. Coordination polymers (CPs) have appeared as efficient photocatalysts for antibiotic degradation, offering a sustainable and promising solution. Herein, a new CdII-based coordination polymer, [Cd5(L)2(bpy)2(H2O)6·2H2O·3DMF]n (1), was synthesized via a solvothermal reaction of 3,5-di(2′,4′-dicarboxylphenyl)benzoic acid (H5L), 4,4′-bipyridine (bpy), and Cd(OAc)2·6H2O. Photocatalytic studies revealed that CP (1) achieves an impressive 93.27 % degradation of furazolidone (FZD) within 55 min under visible light irradiation, outperforming its activity against dimetridazole (DTZ, 58.11 %), metronidazole (MDZ, 49.40 %), ornidazole (ODZ, 41.04 %), and tetracycline (TCY, 62.56 %). The degradation kinetics followed a pseudo-first-order model, with a rate constant (k) of 0.05754 min−1 for FZD. Trapping experiments confirmed that O2•− radicals are the dominant active species driving the photocatalytic degradation process, as further validated by EPR spectroscopy, which provided direct evidence of radical generation under visible light irradiation. This study highlights the potential of Cd(II)-based coordination polymers as efficient photocatalysts for addressing antibiotic contamination in water.