N- and O-donor Co(II) coordination polymers as highly efficient photocatalysts for rapid UV-driven dinotefuran degradation

The uncontrolled use and inadequate disposal of biologically and environmentally relevant substances such as antibiotics, biomolecules, and agricultural pesticides pose serious ecological risks. Herein, we reported two new cobalt(II)-based coordination polymers (CPs), [Co(HL)(bic)(H2O)]·2 H2O ( 1 ) and [Co(HL)(2,2′-bipy)(H2O)]·H2O ( 2 ), designed for the rapid photocatalytic degradation of neonicotinoid pesticide dinotefuran (DTF). The two CPs, constructed from the semi-rigid ligand H3L = 5-[4′-carboxylphenoxy]isophthalic acid and auxiliary N-donor co-ligands bic (3,6-bis(imidazol-1-yl)-9H-carbazole) and 2,2′-bipy (2,2′-bipyridine), exhibit distinct architectures influencing their photocatalytic behavior. Complex 1 , featuring a one-dimensional hydrogen-bonded bilayer framework, achieved 94.36 % DTF degradation within 12 min under UV light, outperforming 2 due to more efficient charge separation and enhanced electron transfer. Radical scavenging studies confirmed the involvement of reactive oxygen species (ROS), mainly superoxide and hydroxyl radicals, in the degradation mechanism. This study highlights the structure–function relationship between coordination topology and photocatalytic efficiency and underscores the potential of Co-based CPs as recyclable photocatalysts for environmental remediation.