Single Crystals of a Covalent Organic Polymer for Photocatalysis

Covalent organic polymers (COPs) with high crystallinity and excellent stability is very important for potential applications in photocatalysis and environmental remediation. However, most COPs are amorphous, limiting their structural characterization, photocatalytic performance, and mechanism exploration. In this study, we report the construction of a crystalline 1D COP (CityU-49) via dative boron←nitrogen (B←N) bonds using 3,6-di(pyridin-4-yl)-9H-carbazole (DPC) as the nitrogen donor and 1,4-bis(benzodioxaborole) as the boron donor. The dynamic and directional nature of B←N bonds enables a self-healing and self-correcting assembly process resulting in a highly crystalline and stable structure. Single-crystal X-ray diffraction (SCXRD) revealed the precise structure of CityU-49 providing insights into its ordered architecture. The photocatalytic performance of CityU-49 was conducted to investigat the degradation of rhodamine B (RhB) (a persistent and toxic organic pollutant). Under UV light irradiation, CityU-49 achieves 95% degradation of RhB in 300 minutes demonstrating excellent photocatalytic activity and environmental applicability. This study highlights the potential of crystalline COPs as efficient and sustainable photocatalysts paving the way for the development of advanced materials for environmental remediation and green technologies.