摘要
采用恒电位法制备了蒽醌二磺酸钠(AQS)掺杂的聚吡咯(PPy)修饰石墨板阴极.石墨板阴极经修饰后,电化学活性得到显著提高,其电子转移内阻及电子转移量分别为未修饰的约50%和5.7倍.实验进一步考察了阴极电位、初始pH值以及Fe2+含量对罗丹明B降解实验的影响,结果表明,在阴极电位为-0.1 V,pH值为3.0,Fe2+浓度为0.2 mmol·L-1的条件下,60 min内对罗丹明B的降解率最高可达85.76%,且长时间运行后,降解效果重复性较好.结合不同条件下的过氧化氢产量和自由基变化淬灭实验,推断了降解过程的机理,即AQS/PPy修饰的石墨板电极,有利于分子氧在电极表面被催化还原为H2O2,和体系中Fe2+产生羟基自由基,故罗丹明B降解是以羟基自由基为主导的电芬顿反应过程.
A graphite plate cathode modified by polypyrrole(PPy)doped with sodium sulfonate(AQS)was prepared by potentiostatic method.The electrochemical activity of graphite plate was significantly improved after modification,and the resistance of electron transfer and electron transfer amount were about 50%and 5.7 times compared to that of the bare graphite plate,respectively.The effects of cathode potential,initial pH and Fe2+content on the degradation characteristics of Rhodamine B were investigated.The results showed that the optimum conditions were as follows:cathode potential(-0.1 V),the pH(3.0),and Fe2+(0.2 mmol·L-1).At the mentioned optimum conditions,the degradation rate of rhodamine B could reached up to 85.76%within 60 min.Duplicated experiments showed the modified cathode had good repeatability.Based on the hydrogen peroxide production in different conditions and free radical quenching experiments,the mechanism of Rhodamine B degradation process was discussed.The AQS/PPy modified graphite plate electrode was favorable to the catalytic reduction of molecular oxygen to generate H2O2.Subsequently,the generated H2O2 reacted with Fe2+to produce hydroxyl radicals,which had strong oxidizing property.So the degradation of Rhodamine B was a hydroxyl radical-dominated electro-Fenton reaction process.
作者
王珊琳
朱维晃
郑飞
査雪聪
WANG Shanlin;ZHU Weihuang;ZHENG Fei;ZHA Xuecong(Key Laboratory of Environmental Engineering,Shaanxi Province,Xi'an University of Architecture and Technology,Xi'an,710055,China;Key Laboratory of Northwest Water Resource,Environment and Ecology,MOE,Xi'an University of Architecture and Technology,Xi'an,710055,China)
出处
《环境化学》
CAS
CSCD
北大核心
2019年第9期2093-2100,共8页
Environmental Chemistry
基金
国家自然科学基金(41373093)资助~~
关键词
聚吡咯/蒽醌修饰
石墨板阴极
电芬顿
罗丹明B降解
polypyrrole/quinine modification
graphite plate cathode
electro-Fenton
RhB degradation
作者简介
通讯联系人;朱维晃,Tel:15664672697,E-mail:zhuweihuang@xauat.edu.cn
