Novel three-dimensional fibrous covalent organic framework constructed via silver amalgam bridging for efficient organic dye adsorption and removal

Abstract

The construction of covalent organic frameworks (COFs) with unique structures is of great significance in exploring the structure-function relationship and extending the potential applications. Fibrous COFs have demonstrated their superior performance in specific application scenarios owing to the distinctive three-dimensional (3D) structure. Herein, we report a facile strategy for the fabrication of 3D COF nanofiber by exploiting silver amalgam as bridging agent to assemble one-dimensional-extended PA-COF modules into tubular structure. The dimension of obtained 3D COF nanofiber is predicted by DFT calculation, and merited with favorable uniformity and high stability. Due to the enhanced exposure of conjugatable binding sites for dye retainment offered by the novel 3D architecture, PA-COF nanofiber exhibits fast adsorption speed (within 5 min) and superior adsorption capacity to various organic dyes, e.g., 1717 mg g-1 for methylene blue (MB) and 978.3 mg g-1 for methyl orange (MO). Moreover, PA-COF nanofiber shows excellent reusability in dye adsorption, making it potential media in removing dye pollutants from wastewater. This work presents an effective strategy to construct COF materials of unique architecture with potential prospect in the fields of separation and wastewater treatment.