羧基化多壁碳纳米管促进类芬顿体系催化降解苄氯酚  

Enhanced removal of Chlorofene catalyzed by a Fenton-like system in the presence of carboxylated multi-walled carbon nanotubes

作　　者：薛洁[1] 彭建彪[1] 焦昭钰 薛乐平[1] 黄俊帆 高士祥[1] Xue Jie Peng Jianbiao Jiao Zhaoyu Xue Leping Huang Junfan Gao Shixiang(State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China)

机构地区：[1]污染控制与资源化研究国家重点实验室南京大学环境学院,南京210023

出　　处：《南京大学学报（自然科学版）》2017年第2期238-244,共7页Journal of Nanjing University（Natural Science）

基　　金：南京大学本科生国家创新计划(G201610284049)

摘　　要：碳纳米管因其独特的物理化学性能和优异的电子传递特性使其成为众多研究工作者在研究高效催化剂及催化剂载体领域关注的热点.以常用消毒剂苄氯酚(CF)为新型污染物的代表,研究了羧基化多壁碳纳米管对类芬顿体系降解苄氯酚的作用,考察了pH、温度、Fe^(3+)和H_2O_2浓度等对反应的影响.结果表明:在pH=4的条件下,适量的羧基化多壁碳纳米管可以提高苄氯酚的去除率,且去除率随着温度、Fe^(3+)和H_2O_2浓度的增加而增加;当[Fe^(3+)]=0.05mmol·L^(-1),[H_2O_2]=1.0 mmol·L^(-1),[CF]=0.02 mmol·L^(-1),[MWCNTs-COOH]=4ppm时,25℃条件下CF降解速率由不加碳纳米管时的0.0047min^(-1)增加到0.1029min^(-1),提升了20多倍.通过自由基淬灭和电子顺磁共振技术来测定反应过程中的活性氧化物种,结果表明羟基自由基(·OH)为主要的活性氧化物种.最后,用飞行时间液相色谱质谱联用仪(TOF5600LC-MS)检测到苄氯酚的三种羟基化中间产物.Recently,carbon nanotubes（CNTs）have attracted increasing attention due to their exceptional physical and chemical properties and their excellent electron transfer property in high efficient catalysts or carriers of catalysts research field.In this paper,the role of carboxylated multi-walled carbon nanotubes（MWCNTs-COOH）played in the degradation of chlorofene（CF）by a Fenton-like system Fe3＋/H2O2 was studied.The effects of reaction parameters,such as pH,Fe3＋concentration,H2O2 concentration,MWCNTs-COOH concentration,and reaction temperature have also been investigated.The results indicated that the addition of MWCNTs-COOH exhibited an enhanced effect on CF oxidation,and the removal efficiency of CF increased with increasing Fe3＋concentration,H2O2 concentration,and reaction temperature.The degradation pseudo-first-order kinetic rate constant of CF increased more than 20 times in the system containing 0.05mmol·L-1 Fe3＋,1.0mmol·L-1 H2O2,0.02mmol·L-1 CF and 4ppm MWCNTs-COOHat 25 ℃than that in the same system but omitting MWNCTs-COOH.In order to have a better understanding of the reaction mechanism,radical quenching assays were carried out,and electron paramagnetic resonance（EPR）technology was employed to determine the reactive oxygen species（ROS）.The results suggested that hydroxyl radical（·OH）was the dominant ROS,which may be responsible for the decomposition of CF.Finally,three intermediates of CF were identified using an electrospray time-of-flight mass spectrometer（TOF 5600LC-MS）.

关 键 词：羧基化多壁碳纳米管 类芬顿体系 苄氯酚 活性氧化物种 

分 类 号：TP181[自动化与计算机技术—控制理论与控制工程]