Guangzhou Customs Technology Center, Guangzhou, 510623, China.
Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, College of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
Chemosphere. 2023 Oct;337:139377. doi: 10.1016/j.chemosphere.2023.139377. Epub 2023 Jul 2.
In this study, the selective adsorption of aromatic compounds on mesoporous MIL-53(Al) was investigated, and followed the order: Biphenyl (Biph) > Triclosan (TCS) > Bisphenol A (BPA) > Pyrogallol (Pyro) > Catechol (Cate) > Phenol (Phen), and exhibited high selectivity toward TCS in binary compounds. In addition to hydrophobicity and hydrogen bonding, π-π interaction/stacking predominated, and more evidently with double benzene rings. TCS-containing halogens could increase π interaction on the benzene rings via forming Cl-π stacking with MIL-53(Al). Moreover, site energy distribution confirmed that complementary adsorption mainly occurred in the Phen/TCS system, as evidenced by ΔQ (the decreased solid-phase TCS concentration of the primary adsorbate) < Q (the solid-phase concentrations of the competitor (Phen)). In contrast, competitive sorption occurred in the BPA/TCS and Biph/TCS systems within 30 min due to ΔQ = Q, followed by substitution adsorption in the BPA/TCS system, but not for the Biph/TCS system, likely attributed to the magnitude of energy gaps (E) and bond energy of TCS (1.80 eV, 362 kJ/mol) fallen between BPA (1.74 eV, 332 kJ/mol) and Biph (1.99 eV, 518 kJ/mol) according to the density-functional theory of Gaussian models. Biph with a more stable electronic homeostasis than TCS lead to the occurrence of substitution adsorption in the TCS/BPA system, but not in the TCS/Biph system. This study provides insight into the mechanisms of different aromatic compounds on MIL-53(Al).
在这项研究中，研究了介孔 MIL-53(Al) 对芳香族化合物的选择性吸附，其顺序为：联苯（Biph）>三氯生（TCS）>双酚 A（BPA）>邻苯二酚（Pyro）>儿茶酚（Cate）>苯酚（Phen），并在二元化合物中对 TCS 表现出高选择性。除疏水性和氢键外，π-π 相互作用/堆积也占主导地位，且具有两个苯环时更为明显。TCS 中含有的卤素可以通过与 MIL-53(Al) 形成 Cl-π 堆积来增加苯环上的 π 相互作用。此外，位点能量分布证实，在 Phen/TCS 体系中主要发生互补吸附，这可以通过 ΔQ（主要吸附质的固相反响物 TCS 浓度降低）<Q（竞争物（Phen）的固相反响物浓度）来证明。相比之下，在 30 分钟内，BPA/TCS 和 Biph/TCS 体系中发生竞争吸附，因为 ΔQ=Q，随后在 BPA/TCS 体系中发生取代吸附，但在 Biph/TCS 体系中没有发生取代吸附，这可能归因于能量间隙（E）和 TCS 的键能（1.80 eV，362 kJ/mol）的大小，根据高斯模型的密度泛函理论，TCS 介于 BPA（1.74 eV，332 kJ/mol）和 Biph（1.99 eV，518 kJ/mol）之间。Biph 比 TCS 具有更稳定的电子平衡，导致 TCS/BPA 体系中发生取代吸附，而 TCS/Biph 体系中没有发生取代吸附。本研究深入了解了不同芳香族化合物在 MIL-53(Al) 上的作用机制。
