High surface area benzimidazole based porous covalent organic framework for removal of methylene blue from aqueous solutions
Omid Rahmanian, Molood Falsafin, Mohammad Dinari
Abstract
Abstract In this study, a highly thermally stable benzimidazole based covalent organic framework (bCOF) was synthesized by the reaction of perlin‐tetracarboxylic anhydride, 5‐aminoisophthalic acid and diaminobenzidine in polyphosphoric acid medium. The synthesized porous bCOF was identified by different techniques. From CO 2 adsorption, the micropore surface area of the bCOF was found to be 856 m 2 g −1 ; this synthesized bCOF has a widespread netting construction, and it has various porosity. The TGA results displayed the high thermal strength of the synthesized bCOF. After characterization, the bCOF was used for the removal of methylene blue from aqueous solution, and the essential parameters such as pH of the solution, contact time and initial concentration were assessed. The maximum adsorption capacity of the bCOF for removal of methylene blue was 63.29 mg g −1 after only 40 min contact time at a pH of 6. Two kinetics and adsorption models were used for interpretation, and the outcomes showed that the pseudo‐second‐order and Langmuir models respectively were better fitted to the results. According to the results, the novel bCOF can be applied to remove methylene blue from aqueous solution. © 2020 Society of Chemical Industry