Facile synthesis of multifunctional magnetic porous organic polymers with high catalytic performance and dye adsorption capacity

Abstract

Based on a diazo-coupling process in an aqueous solution under mild conditions, we presented a template-free technique for synthesizing multiple-functionality magnetic porous organic polymers (MOPs) with rich sulfide and free phenolic hydroxyl groups. The resulting pure porous organic polymer (POP) exhibits a large Brunauer–Emmett–Teller (BET) specific surface area of 268.6 m² g⁻¹, and MOPs have a surface area ranging from 179.91 m² g⁻¹ to 211.8 m² g⁻¹. Thermogravimetric analysis (TGA) indicate high thermal stability. Considering the advantages such as their porous nature and abundant adsorption sites, both MOP-F and MOP-H are highly capable of interacting with metal ions and cationic dyes, including methylene blue (MB). The polymers complexed with indium showed excellent catalytic performance for the synthesis of tetrazole derivatives. Moreover, the MOPs exhibited high adsorption capability for the cationic dye methylene blue with a maximum adsorption capacity of 1060 mg g⁻¹. Because of the superparamagnetic properties of the synthesized MOPs, they could be easily separated from the media. The collected MOPs could be reused for four more rounds without a significant decrease in adsorption capacity.