Green synthesis of an ionic porous organic polymer for efficient capture of environmentally toxic MnO4− and I3− from water†

Abstract

The syntheses of ionic porous organic polymers (iPOPs) via an ionothermal strategy or using solvents with high boiling points are not environmentally friendly approaches. Furthermore, green synthesis of an ionic porous organic polymer has not been reported to date. The azo-coupling reaction is considered a green synthetic strategy and has been used to obtain a new ionic porous organic polymer (iPOP-6) wherein water is used as a solvent. iPOP-6 turns out to be a useful adsorbent that can scavenge toxic water pollutants (MnO₄⁻ and I₃⁻) in an energy efficient manner via an ion exchange based adsorption process. The distribution coefficients (K_d) associated with the removal of MnO₄⁻ and I₃⁻ are greater than 10⁵ mL g⁻¹ – a desirable feature observed in a superior adsorbent. iPOP-6 can remove such pollutants from water samples collected from different water bodies with good capture efficiency. The removal mechanism was also ratified by theoretical studies. Overall, this work presents a new ionic POP with improved features and performance for water purification applications.