The adsorptive mechanisms operating in, and the effect of two different thiol modification methods on, the removal of five iodinated trihalomethanes (I-THMs) by the Zeolite Imidazolate Framework (ZIF-8) were investigated in single and mixed solutions. The direct postgrafting of dithioglycol to the zinc complex node of ZIF-8 (ZF-SH) can increase the mesopore structures that enhance inner pore accessibility; this increase is a critical property required for excellent adsorption of I-THMs. The synergetic adsorptive interactions consist of Lewis acid-base interactions via the Zn-Zn complex, ion-dipole interactions involving the protonated hydroxyl and thiol groups, and hydrophobic interactions at the imidazole ring. In contrast to ZF-SH, the (3-mercaptopropyl)-trimethoxy functionalized silica coating on ZIF-8 (ZF-Si-SH) causes a lower thiol moiety and a steric effect that is reflected in its lower adsorption capacity. In both single and mixed solutions, the small molecular size and hydrophobic nature of I-THMs can promote better adsorption capacity on all thiol-modified ZIF-8, while the minus dipole charge distribution of the I-THMs structure plays a more critical role in selective adsorption on pristine ZIF-8. Interestingly, the dehalogenation of triiodomethane to diiodomethane due to a nucleophilic substitution (S_N2) reaction can be accelerated by the thiol functionalized silica layer on ZIF-8.

在单一和混合溶液中，研究了沸石咪唑酸盐骨架（ZIF-8）在两种硫醇修饰方法上的吸附机理以及两种不同的巯基修饰方法对五种碘代三卤甲烷（I-THMs）的去除作用。将二硫代二醇直接后接枝到ZIF-8（ZF-SH）的锌络合物节点上可以增加介孔结构，从而增强内部孔的可及性。这种增加是I-THM出色吸附所需的关键特性。协同吸附相互作用包括通过Zn-Zn络合物的路易斯酸碱相互作用，涉及质子化的羟基和巯基的离子-偶极相互作用以及在咪唑环上的疏水相互作用。与ZF-SH相比，ZIF-8（ZF-Si-SH）上的（3-巯基丙基）-三甲氧基官能化二氧化硅涂层导致较低的硫醇部分和空间效应，这反映在其较低的吸附能力上。在单溶液和混合溶液中，I-THM的小分子大小和疏水性质都可以促进在所有巯基修饰的ZIF-8上的更好吸附能力，而I-THMs结构的负偶极电荷分布在在原始ZIF-8上的选择性吸附。有趣的是，由于亲核取代作用，三碘甲烷脱卤为二碘甲烷（S I-THMs结构的负偶极电荷分布在原始ZIF-8的选择性吸附中起更关键的作用。有趣的是，由于亲核取代作用，三碘甲烷脱卤为二碘甲烷（S I-THMs结构的负偶极电荷分布在原始ZIF-8的选择性吸附中起更关键的作用。有趣的是，由于亲核取代作用，三碘甲烷脱卤为二碘甲烷（S_N 2）反应可以通过ZIF-8上的硫醇官能化二氧化硅层来加速。