迪美唑在光催化剂TiO_2表面吸附特征及降解机理的理论研究  

Adsorption characteristics and degradation mechanism of DMZ on photocatalyst TiO_2 surface:a density functional theoretical study

作　　者：徐伯华[1] 张福兰[1] 魏维[2] 陈晓 李来才[2] 田安民[3] Bohua Xu;Fulan Zhang;Wei Wei;Xiao Chen;Laicai Li;Anmin Tian(College of Chemistry and Chemical Engineering,Yangtze Normal University,Fuling 408100,China;of Chemistry and Material Science,Sichuan Normal University,Chengdu 610066,China;College of Chemistry,Sichuan University,Chengdu 610064,China)

机构地区：[1]长江师范学院化学化工学院,涪陵408100 [2]四川师范大学化学与材料科学学院,成都610066 [3]四川大学化学学院,成都610064

出　　处：《中国科学：化学》2019年第2期368-379,共12页SCIENTIA SINICA Chimica

基　　金：四川省自然科学基金(编号:2014JY0099)资助项目

摘　　要：本文采用密度泛函理论研究了迪美唑在锐钛矿TiO_2(101)和(001)晶面的吸附和降解反应机理,分别研究了真空和中性水溶剂条件下,迪美唑在锐钛矿表面吸附的稳定性特征,理论优化了最稳定的吸附构型.研究发现在两种条件下,迪美唑均能吸附在TiO_2表面,吸附过程产生的氢键能增强吸附结构的稳定性,稳定的吸附构型使得迪美唑的C–N键变长,有利于发生开环降解反应.本文还研究了迪美唑在锐钛矿TiO_2两个晶面上的开环降解反应机理.研究发现,在TiO_2(101)晶面迪美唑开环降解所需反应活化能较高,很难发生,而在(001)晶面迪美唑开环可在热反应条件下进行.在水溶剂条件下,迪美唑在锐钛矿TiO_2晶面上的降解反应活化能有所降低,可见溶剂条件能促进降解反应的进行.In this article,the adsorption and degradation mechanism of dimetridazole(DMZ)on anatase TiO2(101)and(001)crystal surfaces has been studied by density functional theory.The adsorption stability of DMZ on anatase surface was studied under vacuum and neutral water solvents.The most stable adsorption configuration was optimized by theoretical analysis.It was found that DMZ can be adsorbed on photocatalyst TiO2 surface under two conditions.The hydrogen bond produced in the adsorption process can enhance the stability of the adsorption structure.The stable adsorption configuration makes the C–N bond length of DMZ longer,which is conducive to the ring opening degradation reaction.We also studied the mechanism of ring opening degradation of DMZ on two crystal planes of anatase TiO2.It was found that the reaction activation energy of the degrading reaction on TiO2(101)crystal surface is very high,and the ring opening reaction is difficult to occur.On the(001)crystal surface,the opening of DMZ can be carried out under the condition of thermal reaction.We studied the effect of the water solvation on the degradation reaction.It was found that the activation energies of DMZ on the anatase TiO2 surface was reduced,indicating that the solvent conditions could promote the degradation reaction.

关 键 词：密度泛函理论 TIO2光催化剂 迪美唑 降解 反应机理 

分 类 号：X703[环境科学与工程—环境工程] O643.36[理学—物理化学]