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文獻(xiàn)名： Enhanced Adsorption of p-Arsanilic Acid from Water by Amine-Modified UiO-67 as Examined Using Extended X-ray Absorption Fine Structure, X-ray Photoelectron Spectroscopy, and Density Functional Theory Calculations
作者：Chen Tian†§, Jian Zhao‡§ , Xinwen Ou†, Jieting Wan†, Yuepeng Cai∥, Zhang Lin*† , Zhi Dang†, and Baoshan Xing⊥
† School of Environment and Energy, Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters (Ministry of Education), Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, South China University of Technology, Guangzhou 510006, China
‡ College of Environmental Science and Engineering, Key Laboratory of Marine Environmental Science and Ecology (Ministry of Education), Ocean University of China, Qingdao 266100, China
∥ School of Chemistry and Environment, South China Normal University, Guangzhou 510006, China
⊥ Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States
摘要：p-Arsanilic acid (p-ASA) is an emerging organoarsenic pollutant comprising both inorganic and organic moieties. For the efficient removal of p-ASA, adsorbents with high adsorption affinity are urgently needed. Herein, amine-modified UiO-67 (UiO-67-NH2) metal–organic frameworks (MOFs) were synthesized, and their adsorption affinities toward p-ASA were 2 times higher than that of the pristine UiO-67. Extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation results revealed adsorption through a combination of As–O–Zr coordination, hydrogen bonding, and π–π stacking, among which As–O–Zr coordination was the dominant force. Amine groups played a significant role in enhancing the adsorption affinity through strengthening the As–O–Zr coordination and π–π stacking, as well as forming new adsorption sites via hydrogen bonding. UiO-67-NH2s could remove p-ASA at low concentrations (<5 mg L–1) in simulated natural and wastewaters to an arsenic level lower than that of the drinking water standard of World Health Organization (WHO) and the surface water standard of China, respectively. This work provided an emerging and promising method to increase the adsorption affinity of MOFs toward pollutants containing both organic and inorganic moieties, via modifying functional groups based on the pollutant structure to achieve synergistic adsorption effect.
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