Ag掺杂WO_(3)光催化杀灭大肠杆菌的性能及机理  

Enhanced photocatalytic disinfection of Escherichia coli by WO_(3) doped with Ag

作　　者：张茂祯 赵师祎 赵冬冬 黄丹 汪美贞[1] 周芷若 ZHANG Maozhen;ZHAO Shiyi;ZHAO Dongdong;HUANG Dan;WANG Meizhen;ZHOU Zhiruo(School of Environmental Science and Engineering,Zhejiang Gongshang University,Hangzhou 310018)

机构地区：[1]浙江工商大学环境科学与工程学院,杭州310018

出　　处：《环境科学学报》2024年第12期143-155,共13页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.22306163,42107035);浙江省自然科学基金(No.LQ23B070001);浙江工商大学“数字+”学科建设项目(No.SZJ2022C007);浙江省教育厅一般科研项目(No.Y202250134)。

摘　　要：部分天然水体中存在大量病原菌,严重威胁人类健康,并引起生态系统失衡,亟需有效的技术手段进行杀灭.光催化技术已广泛应用于水体环境污染物的处理,然而,现有光催化剂存在波长响应范围小或光生电子-空穴易复合等问题.因此,我们设计出一种以WO_(3)为基底的光催化剂,通过3%Ag元素掺杂提升了电子-空穴分离效率并抑制其复合,从而高效灭活病原菌.具体而言,本文探究在可见光下,Ag元素掺杂的以WO_(3)为基底的光催化剂对大肠杆菌(E.coli)的灭活性能.结果表明,Ag以3%质量比掺杂WO_(3)(AgWO_(3)-3)具有最佳杀菌效率,光照40 min后,大肠杆菌密度可由10^(7.23)CFU·mL^(-1)降低至10^(2.30)CFU·mL^(-1).后进一步分析了AgWO_(3)-3在不同浓度腐植酸、p H值和盐度条件下对E.coli的灭活作用,结果显示Ag WO_(3)-3在光催化系统均促进杀灭E.coli的性能.进一步分析AgWO_(3)-3的光电性质,光致发光图谱揭示Ag WO_(3)-3电子和空穴的复合得到了抑制,光电流显示AgWO_(3)-3可产生更多的光生载流子,证实了AgWO_(3)-3电子-空穴分离效率得到提升.这是Ag WO_(3)-3灭活E.coli性能优越的原因.ROS淬灭实验表明发挥主要作用的活性氧物种(ROS)显示为·O_(2)^(-)和·OH,EPR测试进一步表明了·O_(2)^(-)和·OH的产生.基于上述结果,Ag掺杂可以作为提升WO_(3)光催化性能的有效方法,Ag-WO_(3)可以作为长期稳定的大肠杆菌光灭活催化剂.Photocatalysis technology has been extensively applied in environmental pollutant remediation in water.Water contains numerous pathogens,posing significant threats to human health and ecosystem equilibrium.However,prevailing photocatalysts encounter challenges like limited wavelength responsiveness and facile recombination of photogenerated electron-hole pairs.To address this,we developed a novel photocatalyst employing element doping for enhanced pathogen inactivation.This study explores the disinfection efficacy of WO_(3)-based photocatalysts against Escherichia coli(E.coli)under visible light.Results indicate that WO_(3) doped with 3%Ag(Ag WO_(3)-3)exhibits optimal bactericidal activity,the E.coli density decreased from 10^(7.23)CFU·mL^(-1)to 10^(2.30)CFU·mL^(-1)after 40 minutes of light exposure.Additionally,the influence of AgWO_(3)-3 on E.coli inactivation was assessed under varying concentrations of humic acid,p H levels,and salinity,demonstrating sustained disinfection activity within the photocatalytic system.Subsequent analysis delves into the optical and electrochemical properties of AgWO_(3)-3.Photoluminescence spectra reveal suppressed electron-hole recombination,while photocurrent measurements indicate heightened charge carrier generation under light excitation,potentially contributing to the superior E.coli inactivation by AgWO_(3)-3.Reactive oxygen species(ROS)quenching experiments identify·O_(2)^(-)and·OH as primary ROS,corroborated by EPR tests revealing·O_(2)^(-)and·OH production.In summary,Ag doping can serve as an effective method to enhance the photocatalytic performance of WO_(3),and AgWO_(3)-3 can function as a long-term stable photocatalyst for E.coli disinfection.

关 键 词：WO_(3) 元素掺杂 大肠杆菌 环境因素 

分 类 号：X131[环境科学与工程—环境科学]