posted on 2023-11-07, 21:43authored byYilei Fang, Qian Guan, Mengyu Tang, Xinyu Zhang, Xu Wu, Huabin Zeng, Xin Yu, Ranwen Ou
Elimination
of toxic Cr(VI) in industrial effluent is essential;
numerous adsorbents have been developed for Cr(VI) adsorption, but
a sustainable adsorbent with chemical-less and environmentally friendly
regeneration methods that could greatly reduce chemical eluent usages,
recycling costs, and secondary pollution is still lacking. Here, we
report a copolymer network of diallyldimethylammonium chloride and N-isopropylacrylamide (pDDA-pNIPAm) functionalized metal–organic
framework (MOF) materials as a thermally regenerable cationic ion
adsorbent (pDDA-pNIAPm-MIL-53) for highly selective and sustainable
Cr(VI) removal. At room temperature (ca. 25 °C), it quickly adsorbed
Cr(VI) oxyanions from water with a maximum adsorption capacity of
45.5 mg g–1, showing a remarkable Cr(VI) selectivity
up to 130 in the presence of coexisting anions with ion molar ratio
of 1:1. Importantly, pDDA-pNIAPm-MIL-53 with adsorbed ions could be
efficiently regenerated in warm water (35–50 °C) with
excellent reusability, so the low-grade waste heat from Cr(VI) pollutant
industries can be used as an energy source. The high selectivity and
thermal regeneration ability of this adsorbent ensure the efficient
removal of Cr(VI) from water and the high purity of Cr(VI) from regeneration.
This work provides scientific support for designing MOFs with selective
adsorption behavior and thermally regenerable function for highly
selective toxic ion removal and sustainable regeneration.