Pyridinium‐Functionalized Ionic Porous Organic Polymer for Rapid Scavenging of Oxoanions from Water

Abstract

Metal oxoanions adversely affect the food chain through bioaccumulation and biomagnification. Therefore, they are among the major freshwater contaminants that require immediate remediation. Although several adsorbents are developed over the years for sequestering these micropollutants, the selective removal of oxoanions remains still a formidable challenge. Herein, pyridinium and triazine‐based ionic porous organic polymer, iPOP‐Cl, developed through a Brønsted acid‐catalyzed aminal formation reaction, is reported as a suitable anion exchange material for the selective removal of metal oxoanions from wastewater. The positively charged nitrogen centers, along with exchangeable chloride counter‐ions in the porous polymer, allow facile oxoanion uptake. iPOP‐Cl is found to be a selective scavenger of permanganate (MnO4−) and dichromate (Cr2O72−) from water in the presence of a high concentration of competing anions generally found in brackish water. The material exhibits fast sorption kinetics, a high uptake capacity (333 mg g−1 for MnO4− and 358 mg g−1 for Cr2O72−), and excellent recyclability.

Enhancement of Mass Transfer Process for Photocatalytic Reduction in Cr(VI) by Electric Field Assistance

“…After calculation ( Table S3 ), the R 2 of the Langmuir model (R 2 = 0.99023) is greater than that of the Freundlich model (R 2 = 0.94536), indicating that the Langmuir model can better describe the adsorption process, which is monolayer adsorption. And the theoretical maximum adsorption capacity can be up to 189.39 mg/g, showing good adsorption capacity of Cr(VI) ( Table S4 [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]).…”

Structural Modulation of Nitrogen-Rich Covalent Organic Frameworks for Iodine Capture

“…Molecular adsorption in solid porous materials is a complex process. − Multiple factors such as porosity, crystallinity, flexibility, and density of binding sites in the porous skeleton collectively determine the efficiency of the adsorption process, especially in COFs. , The two COFs possessed comparable porosity (surface area, pore size, and pore volume), and thus, the porosity factor could not be the prime consideration of adsorption activity. As no contrasting morphological difference is observed (Figure S16), there could be hardly any clear correlation between the morphology and iodine uptake properties of TTPA-COF and TAPT-COF.…”