新型光催化体系的作用机制及其对环丙沙星降解机理的液相色谱-质谱分析

Characterization of a New Photocatalytic System and Its Degradation Mechanism Toward Ciprofloxacin by Liquid Chromatography-Mass Spectrometry

以碳纳米管(CNTs)为负载,与柠檬酸铁(Fe-Cit)耦合制备光催化剂,并以该催化剂激活过硫酸盐(PS),构建了一种新型稳定且有效的非均相催化氧化体系。借助紫外-可见(UV-Vis)漫反射光谱、电子顺磁共振(EPR)、X射线光电子能谱(XPS)等手段,评价了该体系的催化性能,探究了体系中两大活性物种(·OH和SO-4)及其作用机制。在模拟日光(氙灯)下,利用自制的Fe-Cite@CNTs/PS新型光催化氧化体系,对溶液状态中的环丙沙星进行降解,利用液相色谱-质谱(LC-MS)联用技术测定了降解率,并对降解产物进行分析鉴定,通过匹配和分子式模拟,初步探究了环丙沙星的光催化降解机理。

A new stable and effective heterogeneous catalytic oxidation system was formed by coupling multi-walled carbon nanotubes(CNTs)with ferric citrate(Fe-Cit)to activate persulfate(PS).The catalytic performance of the system was evaluated by means of UV-Vis,EPR and XPS spectra,and the mechanism of actions of the active species(·OH and SO-4)in the system was studied.Ciprofloxacin in solution was degraded by the new system of Fe-Cit@CNTs/PS under simulated sunlight(xenon lamp).The degradation rates were determined by liquid chromatography-tandem mass spectrometry,and the degradation products were analyzed and identified.At the same time,the photocatalytic degradation pathway of ciprofloxacin was preliminarily explored through matching and molecular simulation.