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Abstract：
In this study, ionic liquids (ILs) were used as organic modifiers by introducing montmorillonite nanolayers containing potential C and N active sites between the montmorillonite nanolayers. Organically modified montmorillonite (ILs-Mt-p) was further prepared by high-temperature pyrolysis under N2 and used for the removal of ofloxacin (OFL) by activated peroxymonosulfate (PMS). Combined with XPS and other characterization analyses, it was found that the catalyst materials prepared from different organic modifiers had similar surface functional groups and graphitized structures, but contained differences in the types and numbers of C and N active sites. The catalyst (3CPC-Mt-p) obtained after pyrolysis of montmorillonite modified with cetylpyridinium chloride (CPC) had optimal catalytic performance, in which graphitic C, graphitic N, and carbonyl group (C[bond, double bond]O) could synergistically promote the activation of PMS by electron transfer, and 77.3 % of OFL could be removed within 60 min. The effects of OFL concentration, initial pH, and anions on the effects of OFL removal by the 3CPC-Mt-p/PMS system were further investigated. Satisfactory degradation results were obtained over a wide pH range. Cl- promoted the system to degrade OFL, while the presence of SO42-, H2PO4- and HA showed some inhibition, but overall the 3CPC-Mt-p catalysts had a strong anti-interference ability, showing good application prospects. The quenching experiments and EPR tests showed that O2-- and 1O2 in the 3CPC-Mt-p/PMS system were the main reactive oxygen species for the degradation of OFL, and •OH was also involved in the reaction. This study provides ideas for the construction and modulation of active sites in mineral materials such as montmorillonite and broadens the application of montmorillonite composite catalysts in advanced oxidation processes for the treatment of antibiotic wastewater.
摘要：
在这项研究中,通过在蒙脱石纳米层之间引入含有潜在C和N活性位点的蒙脱石纳米层，将离子液体（IL）用作有机改性剂。通过在N2下高温热解进一步制备有机改性蒙脱石（ILs-Mt-p），并用于通过活化的过氧单硫酸盐（PMS）去除氧氟沙星（OFL）。结合XPS和其他表征分析，发现由不同有机改性剂制备的催化剂材料具有相似的表面官能团和石墨化结构，但在C和N活性位点的类型和数量上存在差异。氯化十六烷基吡啶(CPC)改性蒙脱土热解后得到的催化剂(3CPC-Mt-p)具有最佳的催化性能,其中石墨C，石墨N,和羰基(C[键，双键]O)可以通过电子转移协同促进PMS的活化，60min内可去除77.3%的OFL。OFL浓度的影响，初始pH值,进一步研究了阴离子对3CPC-Mt-p/PMS系统去除OFL的影响。在宽的pH范围内获得满意的降解结果。Cl-促进了系统降解OFL，而SO42-的存在，H2PO4-和HA显示出一定的抑制作用，但总体而言，3CPC-Mt-p催化剂具有很强的抗干扰能力，具有良好的应用前景。猝灭实验和EPR测试表明，3CPC-Mt-p/PMS体系中的O2-和1O2是降解OFL的主要活性氧，和·OH也参与反应。该研究为蒙脱石等矿物材料中活性位点的构建和调制提供了思路，拓宽了蒙脱石复合催化剂在抗生素废水处理高级氧化工艺中的应用。
