弱可见光激发介孔TiO_(2)复合催化剂降解海水中抗生素的机理对比  

Comparative study of degradation mechanism of antibiotics pollutants in seawater via mesoporous TiO_(2) composite catalyst excited by weak visible light

作　　者：陈嘉奕 刘忆 朱羽科 吴礼光[1] 陈华丽 高莉丽 王挺[1] CHEN Jiayi;LIU Yi;ZHU Yuke;WU Liguang;CHEN Huali;GAO Lili;WANG Ting(School of Environmental Science and Engineering,Zhejiang Gongshang University,Hangzhou 310012;Zhejiang Light Industrial Products Inspection and Research Institute,Hangzhou 310012)

机构地区：[1]浙江工商大学,环境科学与工程学院,杭州310012 [2]浙江省轻工业品质量检验研究院,杭州310012

出　　处：《环境科学学报》2024年第12期118-130,共13页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.21776250);浙江省自然科学基金(No.LY19B060004)。

摘　　要：为了探明海水中多相光催化降解污染物过程和性能提升机制,本文首先对比研究了淡水、模拟海水及真实海水中弱可见光激发下氧氟沙星(OFX)和四环素(TC)两种污染物的降解过程,探讨了海水中两种污染物光催化降解过程的差异.而后利用吸附相反应技术在介孔TiO_(2)表面上沉积Ag纳米粒子来提升光催化剂的降解活性.最后,以Ag沉积介孔TiO_(2)催化剂为活性组分制备光催化漂浮球.3种水体系中光催化降解实验表明,海水中盐离子对OFX和TC的降解过程都有抑制作用,但两者分子结构的差异导致OFX光催化降解过程的抑制作用更明显.密度泛函(DFT)计算和中间产物分析发现,OFX分子中受到光生空穴h^(+)和自由基攻击的原子是不同的,最易受到亲电试剂h^(+)攻击的是边缘位原子,盐离子富集严重阻碍了光生空穴h^(+)对该原子的攻击,海水中介孔TiO_(2)催化剂对OFX的去除率均没超过10%.但被降解的OFX可以完全矿化,且短时间产生毒性更低的中间产物.介孔TiO_(2)表面上沉积Ag后,光生电子转移和等离子共振效应可以提升光生空穴和电子的分离率,从而增强催化剂对OFX的降解性能,催化剂对海水中低浓度OFX(1 mg·L^(-1))的去除率接近90%.以Ag沉积介孔TiO_(2)催化剂为活性组分,弱可见光激发下光催化漂浮球对OFX的去除率超过90%(20 h).To explore the mechanism of degradation and performance improvement for pollutants in seawater by multiphase photocatalysis,the degradation of ofloxacin(OFX)and tetracycline(TC)under weak visible light excitation in fresh water,simulated seawater,and real seawater was first carried out.The differences in the photodegradation process of OFX and TC in seawater were comparatively studied.Then,adsorption layer nanoreactor synthesis was used to deposit Ag nanoparticles on the surface of mesoporous TiO_(2) to enhance the performance of the photocatalyst.Finally,photocatalytic floating spheres were prepared using Ag-deposited mesoporous TiO_(2) as the active component.The photodegradation experiments in three water systems showed that salt ions in seawater had inhibitory effects on the degradation process of OFX and TC,but the difference in molecular structure between TC and OFX resulted in a more significant inhibitory effect on the photodegradation for OFX.Density functional theory(DFT)calculations and intermediate product analysis had found that the atoms attacked by photo-generated hole h^(+)and free radicals in OFX molecules were different.The edge atom was most susceptible to electrophilic reagent h^(+)attack,and salt ion enrichment seriously hindered the attack of photogenerated hole h^(+)on this atom.The removal rate for OFX by mesoporous TiO_(2) catalysts in seawater would not exceed 10%However,degraded OFX could be mineralized,and the intermediate products showed lower toxicity in a short time.After the deposition of Ag on the surface of mesoporous TiO_(2),the photogenerated electron transfer and plasma resonance effects would both enhance the separation rate of photogenerated holes and electrons,thereby enhancing the degradation performance for OFX of the catalysts.The removal rate of the catalyst for low concentration OFX(1 mg·L^(-1))in seawater was close to 90%.Using Ag deposited mesoporous Ti O_(2) catalyst as the active component,the removal rate of OFX by the filled floating spheres exceeded 90%(20 h)un

关 键 词：弱可见光催化 Ag沉积 氧氟沙星(OFX) 降解路径 光催化漂浮球 

分 类 号：O647[理学—物理化学] X703[理学—化学]