Green synthesis of novel nitrogen-rich covalent organic polymer for efficient removal of methylene blue from aqueous solutions

A novel nitrogen-rich covalent organic polymer was synthesized through a green synthetic approach by reacting 4,4'-diaminodiphenylsulfone and 4,4',4”-((1,3,5-triazine-2,4,6-triyl)tris(azanediyl))tribenzoic acid. The reaction was conducted under environmentally friendly conditions, utilizing tetra butyl ammonium bromide as a green solvent and triphenyl phosphite as a catalyst. The structure and morphology of the synthesized adsorbent were recognized using TGA, BET, XRD, FT-IR, EDX-Mapping, and FE-SEM analyses. Following characterization, the synthesized adsorbent was employed for the purpose of methylene blue (MB) dye removal. Multiple parameters, including pH, time duration, and initial concentration, were systematically assessed and analyzed. Based on isotherm models, Langmuir was fitted suitably to the experimental data of MB with maximum adsorption of 384.6 mg g−1 at pH 10 in 40 min. After examining the linear regression coefficients (R2), it was determined that the pseudo-second-order model provided a good fit for adsorbing MB.