Fenton溶液预处理对TiO2纳米管催化活性的影响

采用Fenton溶液对TiO2纳米管电极进行预处理,研究其对TiO2纳米管催化活性的影响,考察了Fenton溶液的浓度、配比和处理时间等影响因素,研究了Fenton预处理过程中溶液中二价铁和总铁的含量变化,运用X射线光电子能谱仪(XPS)和场发射扫描电子显微镜(FESEM)对TiO2纳米管电极进行了表征,初步探讨了经处理后TiO2纳米管催化活性再生或增强的机理.结果表明,经Fenton溶液处理后的TiO2纳米管催化活性有明显地提高,Fenton溶液浓度越高,TCs降解率越大(相应于TiO2纳米管催化活性的增强);在一定浓度范围内,H2O2的配比高低对TCs降解率影响较大,其所占比例高,则降解率高,而Fe2+配比高低对TCs降解率影响相对较小.在Fenton溶液处理过程中,溶液中剩余的Fe2+含量较为恒定,总铁的含量呈下降趋势.XPS分析表明,经Fenton溶液处理后,TiO2纳米管电极表面C1s含量降低,O1s、Fe2p含量增大;部分含碳官能团含量明显降低,O1s的电子结合能向高能端位移.

Influence of Fenton pretreatment on catalytic activity of TiO_2 nanotube

This article investigated the effect of TiO2 nanotubes electrodes pretreated with Fenton on their catalytic activity,the influencing factors such as the concentration,mixture ratio of Fenton reagents and the pretreatment time,and also measured the amount of Fe2+ and total iron during pretreatment.The TiO2 nanotubes were characterized using X-ray photoelectron spectroscopy(XPS) and field emission scanning electron microscopy(FESEM).The mechanism of regeneration or enhancement of catalytic activity was analyzed preliminarily.The results show that the catalytic activity of TiO2 nanotubes significantly improved after Fenton pretreatment.Within a certain concentration range,higher Fenton concentrations produced higher TCs degradation efficiency,which corresponds to enhanced catalytic activity for the TiO2 nanotubes.The H2O2 ratio greatly affected TCs degradation efficiency,with a higher ratio resulting in higher degradation efficiency.In contrast,the Fe2+ ratio had little influence on degradation efficiency.During Fenton pretreatment,the amount of Fe2+ in the solution remained essentially constant,but that of total iron decreased.XPS results shows that,after pretreatment,the content of C1s on the TiO2 surface was reduced,and that of O1s and Fe2p showed relative increase.Furthermore,the contents of some carbon functional groups obviously decreased and the O1s XPS peak shifted towards a higher binding energy.