钛酸盐/活性炭吸附协同光催化去除水中4-氯酚  

Synergy of adsorption and photocatalysis for 4-chlorophenol removal using titanate/activated carbon

作　　者：刘月 钱天伟 刘晓娜 冀豪栋 李璠 刘文[2,3] LIU Yue;QIAN Tianwei;LIU Xiaona;JI Haodong;LI Fan;LIU Wen(School of Environmental Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;The Key Laboratory of Water and Sediment Sciences,Ministry of Education,College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China;State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems,Peking University,Beijing 100871,China)

机构地区：[1]太原理工大学环境科学与工程学院,山西太原030024 [2]北京大学环境科学与工程学院,水沙教育部重点实验室,北京100871 [3]北京大学国家环境保护河流全物质通量重点实验室,北京100871

出　　处：《工业水处理》2022年第2期67-74,共8页Industrial Water Treatment

基　　金：国家重点研发计划青年科学家项目(2021YFA1202500);国家自然科学基金(21906001);北京市科技新星计划(Z191100001119054);中国博士后科学基金资助项目(2021M700213)。

摘　　要：通过一步水热法制备了一种钛酸盐/活性炭复合材料(TAC),可高效吸附水中污染物实现预富集,进而在紫外光下光催化降解污染物。研究显示,TAC可在5 min内吸附86.9%的4-氯酚(4-CP),具有比活性炭更快的吸附速率和更大的吸附量,得益于微碳改性钛酸盐后对4-CP的毛细管凝聚作用。TAC可在4 h内光催化降解95.6%预富集的4-CP,实现85.8%的脱氯率。TAC光催化性能显著提升的机理在于其中的活性炭和微碳组分可高效传导光激发生成的光生电子,由此抑制光生载流子复合。猝灭实验与自由基鉴定证实羟基自由基(·OH)是主要活性物种,并通过福井指数理论计算结合中间产物鉴定,确定了4-CP的降解路径主要为·OH取代所导致的C—Cl键断裂及·OH加成。Titanate/activated carbon composite(TAC) was synthesized through a one-step hydrothermal treatment method,which could efficiently pre-concentrate the target organic pollutant through adsorption in water,and then degraded through photocatalysis under UV light. Results showed that TAC achieved 86.9% of 4-chlorophenol(4-CP)adsorption within 5 min,demonstrating that TAC had faster adsorption kinetic rate and larger adsorption capacity compared with original activated carbon. Moreover,TAC could degrade 95.6% of pre-concentrated 4-CP within 4 h through photocatalysis and achieved 85.8% of dechlorination rate. The mechanism enhanced photocatalytic activity of TAC was attributed to the activated carbon and micro-carbon components,which could efficiently transfer the photo-excited electron,thus inhibiting the recombination of photo-generated charge carrier. Hydroxyl radicals(·OH)were proved to be the main reactive species in this reaction system via radical quenching test and radical identification. Meanwhile,the degradation pathway of 4-CP was also confirmed through theoretical calculation on Fukui index and intermediates analysis,which proceeded as C—Cl cleavage after·OH substitution and·OH addition.

关 键 词：钛酸盐 活性炭 预富集 光催化降解 

分 类 号：X52[环境科学与工程—环境工程]