分子印迹型Zn改性石墨相氮化碳(MI-Zn/g-C_(3)N_(4))吸附-降解微囊藻毒素-LR的效能研究  

The efficiency of adsorption and degradation on microcystin-LR by molecularly imprinted Zn-modified graphite phase carbon nitride(MI-Zn/g-C_(3)N_(4))

作　　者：程辉 李航 宋萍[1] 贺琳珂 胡槿宜 封磊[2] CHENG Hui;LI Hang;SONG Ping;HE Linke;HU Jinyi;FENG Lei(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou 350002;College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou 350002)

机构地区：[1]福建农林大学林学院,福州350002 [2]福建农林大学资源与环境学院,福州350002

出　　处：《环境科学学报》2023年第7期172-182,共11页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.31470577);福建省高校产学合作科技重大项目(No.2019N5006);中国烟草总公司福建省公司科技计划项目(No.2022350000240066)。

摘　　要：利用光催化与分子印迹技术,制备了一种对微囊藻毒素-LR(MC-LR)具有选择性降解功能的分子印迹型Zn/g-C3N4复合光催化材料(MIZn/g-C_(3)N_(4)).在此基础之上,对该复合光催化材料的形貌结构与光学性能进行了表征,并对其吸附-降解性能进行了探究.结果表明,分子印迹技术可显著提高光催化材料Zn/g-C_(3)N_(4)比表面积,减小其带隙并扩大对可见光的吸收范围,抑制光生载流子复合,进而提升光催化性能.MI-Zn/g-C_(3)N_(4)对MC-LR的吸附过程可用Langmuir等温吸附模型进行表征,吸附行为属于单层吸附,最大吸附量(Qm)为8.18 mg·g^(-1).而吸附动力学研究则发现,一级和二级动力学模型拟合系数相差不大,表明该吸附体系同时伴随着物理吸附和化学吸附.避光条件下MI-Zn/C_(3)N_(4)在60 min内达到吸附平衡阶段,可吸附约75%的MC-LR.可见光照射下MI-Zn/g-C_(3)N_(4)降解速率最快,4 h内可将2 mg·L^(-1)的MC-LR全部降解.经过5次循环实验,去除效率仍保持在82.16%,表明MI-Zn/g-C3N4具有较好的光催化性能与重复利用能力.·O^(2-)和h+是MI-Zn/g-C_(3)N_(4)光催化降解MC-LR的主要活性物质.In this work,a molecularly imprinted Zn/g-C_(3)N_(4) composite photocatalytic material(MI-Zn/g-C_(3)N_(4))with selective degradation of microcystin-LR(MC-LR)was prepared by combining photocatalytic technology and molecular imprinting technology.Then the morphology structure and optical properties of the composite photocatalytic material were characterized,and its adsorption-degradation properties on MC-LR were investigated.The results showed that the molecular imprinting technique significantly increased the specific surface area of the Zn/g-C_(3)N_(4) photocatalytic material,reduce its band gap,expanded its absorption range of visible light,inhibited its photogenerated carrier recombination,and thus improved its photocatalytic performance.Langmuir model in isothermal adsorption was more suitable to characterize the adsorption process of MI-Zn/g-C_(3)N_(4) on MC-LR.The adsorption behavior belonged to single layer adsorption,and the maximum adsorption capacity(Qm)was 8.18 mg·g^(-1).It could be seen from the kinetic fitting results that the fitting coefficients of the first-order and second-order kinetic models had little difference,implying that the adsorption system was accompanied by both physical adsorption and chemical adsorption.In the dark,the molecularly imprinted Zn-C_(3)N_(4) could reach the adsorption equilibrium stage within 60 minutes,and about 75%MC-LR was adsorbed.The degradation rate of MI-Zn/g-C_(3)N_(4) was the fastest under visible light irradiation,and all 2 mg·L^(-1) MC-LR could be degraded within 4 h.After 5 cycles,the degradation efficiency remained at 82.16%,indicating that MIZn/g-C_(3)N_(4) had good photocatalytic performance and recycling ability.O^(2-)and h+were the major active substances in the molecularly imprinted Zn/g-C_(3)N_(4) photocatalytic degradation of MC-LR.

关 键 词：石墨氮化碳 光催化 分子印迹技术 Zn掺杂 微囊藻毒素-LR 

分 类 号：X703[环境科学与工程—环境工程]