超薄硫掺杂石墨相氮化碳纳米片光催化降解双酚A  

Photocatalytic Degradation of Bisphenol A Using Ultrathin S-Doped Graphitic Carbon Nitride Nanosheets

作　　者：王燚凡 佘少桦 孙传智[2] 朱明山 陆钢 WANG Yifan;SHE Shaohua;SUN Chuanzhi;ZHU Mingshan;LU Gang(School of Environment,Jinan University,Guangzhou 511443,China;College of Chemistry,Shandong Normal University,Jinan 250014,China)

机构地区：[1]暨南大学环境学院,广东广州511443 [2]山东师范大学化学化工与材料科学学院,山东济南250014

出　　处：《环境科学研究》2021年第12期2859-2866,共8页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.51508228);广东省自然科学基金项目(No.2021A1515011804);中央高校基本科研业务费专项资金(No.21620440)。

摘　　要：内分泌干扰物双酚A(BPA)的广泛分布对水环境和人类健康造成了潜在的威胁.为探究超薄硫掺杂的石墨相氮化碳纳米片(US-CN)对BPA的光催化降解性能及其降解机理,使用US-CN对BPA进行了光催化降解,使用电子顺磁共振(EPR)检测了光降解过程中产生的反应性氧自由基(ROS),通过密度泛函理论(DFT)结合自然布局分析(NPA)计算了BPA的原子电荷值,使用LC-MS检测了BPA光催化降解过程的中间产物.结果表明:①US-CN在可见光(VL)下(简称“US-CN/VL体系”)100 min内对BPA的去除率可达66.39%,去除率的准一级反应动力学常数约为石墨相氮化碳(CN)的6倍.②在US-CN/VL体系中添加L-组氨酸后,60 min内BPA的去除率从50.00%降至6.45%,表明单线态氧(^(1)O_(2))是导致BPA降解的主要ROS.③在US-CN/VL体系中,^(1)O_(2)可能由超氧自由基或溶解氧转化产生.④基于密度泛函理论计算了BPA分子易被^(1)O_(2)攻击的富电子原子位点,并检测出BPA的5种降解中间产物,推测BPA在US-CN/VL体系中可能存在去甲基化和羟基化两种降解路径.研究显示,US-CN在可见光下能产生以^(1)O_(2)为主的ROS,攻击BPA的富电子原子,对BPA有良好的光催化效果.The widespread distribution of endocrine disrupting chemical bisphenol A(BPA)has posed a potential threat to the water environment and human health.This study investigated the photocatalytic degradation performance and mechanism of ultra-thin S-doped graphite phase carbon nitride nanosheets(US-CN)for BPA.US-CN was used for the photocatalytic degradation of BPA.The reactive oxygen species(ROS)generated during photodegradation were detected using electron paramagnetic resonance(EPR).The atomic charge value of BPA was calculated using density functional theory(DFT)and natural population analysis(NPA),and the intermediate products of the photocatalytic degradation of BPA were detected using LC-MS.The results showed that:(1)US-CN degradation rate of BPA reached 66.39%under visible light(VL)for 100 min,and the pseudo-first-order reaction kinetic constant of US-CN degradation was approximately 6 times that of graphite phase carbon nitride(CN).(2)After adding L-histidine to the US-CN/VL system,the removal rate of BPA decreased from 50.00%to 6.45%within 60 min,indicating that^(1)O_(2)was the main ROS for BPA degradation.(3)The^(1)O_(2)from the US-CN/VL system may be converted by superoxide radicals or dissolved oxygen.(4)The electron-rich atoms that were easily attacked by^(1)O_(2)in the BPA molecule and five degradation intermediate products of BPA were found,and two possible degradation pathways of BPA based on demethylation and hydroxylation in the US-CN/VL system were proposed.This work confirmed that under VL,US-CN can generate ROS mainly composed of^(1)O_(2),attacking the electron-rich atoms of BPA molecules,thus US-CN exerts a good photocatalytic effect on BPA degradation.

关 键 词：内分泌干扰物 中间产物 单线态氧(^(1)O_(2)) 密度泛函理论(DFT) 

分 类 号：X52[环境科学与工程—环境工程]