摘要
It is still challenging for exploring high-active photocatalysts to efficiently remove levofloxacin(LFX)by activating peroxymonosulfate(PMS).Herein,we constructed a novel Z scheme ZnFe_(2)O_(4)/g-C_(3)N_(4)/CQDs(ZCC)heterojunction by anchoring ZnFe_(2)O_(4)on tubular-like g-C_(3)N_(4)induced by CQDs(denoted as CNC)using microwave-assisted thermal methods.The ZCC exhibits the highest photocatalytic activity in activating PMS for LFX degradation,endowing a removal rate~95.3%,which is 4.8 and 7.3 times that of pure ZnFe_(2)O_(4)(19.8%)and g-C_(3)N_(4)(13.1%),separately.The enhanced photocatalytic activity of ZCC can be attributed to the distinctive morphology of CNC,enhanced light response,increased specific surface area and abundant pore structure.Besides,the formed Z scheme heterojunction and CQDs acting as a transmission bridge of the photogenerated charges(e−and h+)can accelerate transfer and inhibit recombination of e−and h+.Radical capture experiments and electron spin resonance(ESR)measurements revealed that SO4•-and O2•-play a predominant role in degradation process of LFX.Liquid chromatography-mass spectrometry(LC-MS)was applied to identify intermediates and propose feasible degradation pathways of LFX.In conclusion,this study presents a promising strategy for regulating the photocatalytic activity of g-C_(3)N_(4)by simultaneously integrating CQDs induction and Z scheme heterojunction construction.
通过活化过氧单硫酸盐(PMS)来高效去除左氧氟沙星(LFX)的高活性光催化剂的开发仍是一个挑战。本文采用微波辅助加热的方法,将ZnFe_(2)O_(4)锚定在CQDs诱导的管状g-C_(3)N_(4)(CNC)上,构建了ZnFe_(2)O_(4)/g-C_(3)N_(4)/CQDs (ZCC) Z型异质结。ZCC在活化PMS降解LFX方面表现出最高的光催化活性,去除率达到95.3%,分别是纯ZnFe_(2)O_(4)(19.8%)和g-C_(3)N_(4)(13.1%)的4.8倍和7.3倍。ZCC光催化活性的增强可归因于CNC独特的形貌、增强的光响应、增加的比表面积和丰富的孔结构。此外,形成的Z型异质结和CQDs作为光生电荷(e^(-)和h^(+))的传输桥,可以加速转移并抑制e^(-)和h^(+)的重组。自由基捕获实验和电子自旋共振(ESR)测量表明,SO_(4)^(·-)和O_(2)^(·-)在LFX的降解过程中起主导作用。采用液相色谱-质谱法(LCMS)鉴定中间体,并提出了LFX的可能降解途径。综上所述,本研究提出了一种很有前景的调节gC_(3)N_(4)光催化活性的策略,即同时整合CQDs诱导和Z型异质结构建。
基金
Project(32272823) supported by the National Natural Science Foundation of China
Project(145309315) supported by the Research Foundation of Education Bureau of Heilongjiang Province of China
Project(YSTSXK202309) supported by the Plant Food Processing Technology Advantages Characteristic Discipline “Science and Technology Research” Special Project in Heilongjiang Province,China。
作者简介
Corresponding author:DONG Guo-hua,PhD,Professor,E-mail:ghdong@qqhru.edu.cn,ORCID:https://orcid.org/0000-0001-5972-5418。
