改性Ti/SnO_2-Sb电极降解硝基苯废水  

Degradation of Nitrobenzene Wastewater with Modified Ti/SnO_2-Sb Electrode

作　　者：刘淼[1] 冷粟[1] 陈嵩岳[1] 张亮[1] 张美秀[1] 刘宛宜[1] 沈力[1] 张振斌[1] 刘南[1] 焦昕倩[1] 陈力可[1] 全福民[1] 

机构地区：[1]吉林大学环境与资源学院,地下水资源与环境教育部重点实验室,长春130012

出　　处：《高等学校化学学报》2013年第8期1899-1906,共8页Chemical Journal of Chinese Universities

基　　金：辽河源头区水污染综合治理技术及示范研究项目(批准号:2012ZX07202-009)资助

摘　　要：采用热分解法制备了Ti/SnO2-Sb电极,并通过掺杂Cu,Ni,La,Ce,Nd,Zn和Bi等金属对该电极进行改性.采用扫描电子显微镜(SEM)及X射线衍射(XRD)等方法表征了电极的形貌及晶型;通过加速电极寿命测试和电催化降解硝基苯模拟废水实验,研究了金属掺杂对Ti/SnO2-Sb电极稳定性及电催化活性的影响.根据硝基苯降解的动力学方程分析不同金属掺杂对电极降解速率的影响;通过质谱对硝基苯的降解机理进行了初步探讨;采用水杨酸捕集羟基自由基的液相色谱法测定OH.的浓度.实验结果表明,与空白Ti/SnO2-Sb电极相比,金属掺杂改善了电极的表面形貌和SnO2衍射峰的强度,提高了Ti/SnO2-Sb阳极的电解寿命.对硝基苯模拟废水的电解实验结果表明,掺杂电极的电催化降解能力显著提高,硝基苯的降解符合准一级反应动力学方程.质谱分析结果表明,硝基苯在阴极被还原成苯胺并被氧化降解成其它有机物的过程发生迅速.羟基自由基浓度测定结果表明,自由基浓度越高,硝基苯降解速率越快,反应60 min时,空白Ti/SnO2-Sb电极的OH·浓度只有掺Cu金属电极的1/5.By thermal decomposition, Ti/SnO2-Sb electrodes modified with metals on Ti substrates were prepared. The morphology and crystal structure of the electrodes were analyzed by SEM and XRD. The stability and electric catalytic activity were studied by strengthening the electrode life and the electric catalytic experiment. The degradation rate of the electrodes was analyzed by dynamic equation, the degradation mechanism of nitrobenzene was explored with mass spectrum, and the concentration of OH · was measured by salicylic acid capturing hydroxyl radicals with high performance liquid chromatography. The experimental results show that metal doping improved the surface morphology, changed the diffraction peak intensity of SnO2, prolonged the electrolytic life, and ameliorated the catalytic ability of the electrodes. The degradation of nitrobenzene was identified with quasi first order reaction dynamics equation. The aniline absorption peak was generated on the mass spectrogram at top 5-10 min, after 15 min there was no other absorption peak indicated that the nitrobenzene degraded rapidly after deoxidizing to aniline. The higher concentration of free radicals was, the faster nitrobenzene degradation rate would be. Since it reacted for 60 min, the OH· concentration of the blank electrode fell by one-fifth, comparing to the one mixed with Cu.

关 键 词：半导体电极 电催化氧化 硝基苯 金属掺杂 

分 类 号：O646[理学—物理化学] X701.3[理学—化学]