Abstract

In order to search effective adsorbents for removal of metal ions in water treatments, three nanoporous organic frameworks, TPPA, TPPA-SO3H, and TPBD-SO3H, with or without −SO3H functionalities were selected and synthesized by the Schiff base reactions of 1,3,5-triformylphloroglucinol (TP) and p-phenylenediamine (PA), p-phenylenediaminesulfonic acid (PA-SO3H), and 2,2′-benzidinedisulfonic acid (BD-SO3H), respectively. Characterizations revealed that both TPPA and TPPA-SO3H possess high crystallinity and porosity, while only amorphous powder with irregular pores of TPBD-SO3H was obtained. The Brunauer–Emmett–Teller surface areas of 425.3 and 297.5 m2/g for TPPA and TPPA-SO3H, respectively, were calculated, while only 45.1 m2/g was detected for TPBD-SO3H. Metal ion adsorption experiments revealed that among all three framework materials, TPPA-SO3H shows the best performances in adsorption capacities, removal efficiency, and adsorption rate to all of the tested metal ions, especially Fe3+, Cr3+, and Cd2+ ions. Compared with the absence of −SO3H functionalities in TPPA and the amorphous nature of the extended framework material of TPBD-SO3H, the high performances of TPPA-SO3H should be ascribed to its synergistic effect of functionalization and crystallinity. This study revealed that besides the functional groups, the crystallinity of nanoporous organic frameworks is also a crucial factor in their applications.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call