title: Understanding the Adsorption of PFOA on MIL-101(Cr)-Based Anionic-Exchange Metal-Organic Frameworks: Comparing DFT Calculations with Aqueous Sorption Experiments.
abstract: To examine the effects of different functionalization methods on adsorption behavior, anionic-exchange MIL-101(Cr) metal-organic frameworks (MOFs) were synthesized using preassembled modification (PAM) and postsynthetic modification (PSM) methods. Perfluorooctanoic acid (PFOA) adsorption results indicated that the maximum PFOA adsorption capacity was 1.19 and 1.89 mmol g(-1) for anionic-exchange MIL-101(Cr) prepared by PAM and PSM, respectively. The sorption equilibrium was rapidly reached within 60 min. Our results indicated that PSM is a better modification technique for introducing functional groups onto MOFs for adsorptive removal because PAM places functional groups onto the aperture of the nanopore, which hinders the entrance of organic contaminants. Our experimental results and the results of complementary density functional theory calculations revealed that in addition to the anion-exchange mechanism, the major PFOA adsorption mechanism is a combination of Lewis acid/base complexation between PFOA and Cr(III) and electrostatic interaction between PFOA and the protonated carboxyl groups of the bdc (terephthalic acid) linker.
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China.
authors.forename: Siyu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China.
authors.forename: Xiyue
authors.initials: X
authors.lastname: Hu
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China.
authors.forename: Kunyang
authors.initials: K
authors.lastname: Zhang
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China.
authors.forename: Ajay
authors.initials: A
authors.lastname: Roy
authors.affiliation: School of Environment, Beijing Key Laboratory for Emerging Organic Contaminants Control, State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), Tsinghua University, Beijing 100084, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
mesh_terms: D000327:Adsorption; D000838:Anions; D002210:Caprylates / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D005466:Fluorocarbons / Q000737:chemistry*; D000073396:Metal-Organic Frameworks; D008670:Metals; D055672:Static Electricity
chemical_list: D000838:Anions; D002210:Caprylates; D056831:Coordination Complexes; D005466:Fluorocarbons; C000589635:MIL-101; D000073396:Metal-Organic Frameworks; D008670:Metals; C023036:perfluorooctanoic acid