摘要
针对抗生素污染水体的修复,采用水热法和原位沉积法制备可见光驱动型Ag_(3)PO_(4)/Ag BiVO_(4)异质结光催化剂,并通过XRD、FT IR、SEM、XPS等手段对其相结构、形貌、化学成分进行表征。Ag_(3)PO_(4)/Ag BiVO_(4)复合材料在可见光(λ>420 nm)照射下对盐酸四环素(TCH)降解表现出增强的光催化活性和稳定性。在Ag_(3)PO_(4)与Ag BiVO_(4)物质的量比为1∶2的Ag_(3)PO_(4)/Ag BiVO_(4)2体系中,150 min内对TCH(20 mg/L)的降解率为81.6%,速率常数为0.01002 min 1。光催化活性的增强可归因于Ag BiVO_(4)与Ag_(3)PO_(4)之间紧密的异质结界面和Ag+掺杂的协同效应。通过紫外可见漫反射光谱(UV Vis DRS)、光电流响应和电化学阻抗谱(EIS)等测试证实Ag_(3)PO_(4)/Ag BiVO_(4)具有良好可见光响应和增强的光生电子空穴分离特性,可以促进光生载流子的电荷转移。活性物种捕获试验表明h+和·OH为光催化体系中的主要氧化物质,并基于试验和表征结果提出Ag_(3)PO_(4)/Ag BiVO_(4)复合材料的光降解反应机制。研究表明,Ag_(3)PO_(4)/Ag BiVO_(4)复合材料可作为一种高性能、低成本的可见光驱动型环境污染修复光催化剂。
The visible-light-driven Ag_(3)PO_(4)/Ag BiVO_(4)heterojunction photocatalysts were prepared by hydrothermal and in situ deposition methods for the remediation of antibiotic contaminated water,and characterized by XRD,FT IR,SEM,XPS,and other means for their phase structure,morphology,and chemical composition.The results showed that the synergistic interaction between Ag BiVO_(4)and Ag_(3)PO_(4)reduced the aggregation of the composites and improved the visible light responsiveness and charge separation of the materials.The Ag_(3)PO_(4)/Ag BiVO_(4)series composites exhibited enhanced photocatalytic activity and stability for the degradation of tetracycline hydrochloride(TCH)under visible light(λ>420 nm)irradiation,and the degradation process was following the quasi-first-order kinetic equation.The effect of the molar ratio of Ag BiVO_(4)to Ag_(3)PO_(4)on the properties of the composites was systematically investigated,and the optimum Ag BiVO_(4)to Ag_(3)PO_(4)molar ratio of 2:1 was obtained.The results showed that the Ag_(3)PO_(4)/Ag BiVO_(4)2 composite exhibited the best photocatalytic activity with 81.6%degradation of TC(20 mg/L)within 150 min and the rate constant of 0.01002 min-1.After five photocatalytic reactions,the Ag_(3)PO_(4)/Ag BiVO_(4)2 photocatalyst still maintained high photocatalytic activity.The enhanced photocatalytic activity was mainly attributed to the coupling between Ag BiVO_(4)and Ag_(3)PO_(4)heterogeneous interface,which accelerated the charge separation and transfer.Moreover,the doping of Ag+into BiVO_(4)induced the capturing center of oxygen defects,which effectively inhibited the complexation of photogenerated carriers and maintained excellent redox performance.The excellent visible light response and high photogenerated electron-hole separation properties of Ag_(3)PO_(4)/Ag BiVO_(4)were confirmed by UV Vis DRS,photocurrent response,and EIS tests,which promoted the transfer of photogenerated carriers and thus generated more active substances to participate in photocatalytic reactions.In addition,the results of radical trapping experiments showed that h+and·OH were the main oxidizing substances for TCH degradation in the photocatalytic system species.Based on the experimental and characterization results,the rational mechanism and electron transfer mechanism of the Ag_(3)PO_(4)/Ag BiVO_(4)photocatalytic system were proposed.In this work,visible light-responsive and more stable bismuth-based heterojunction photocatalysts were constructed for the efficient treatment of persistent pollutants in wastewater.
作者
李靖
程凯
杨超思
郭冀峰
卢昶雨
LI Jing;CHENG Kai;YANG Chaosi;GUO Jifeng;LU Changyu(Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region,Ministry of Education,School of Water and Environment,Chang'an University,Xi'an 710054,China;Hebei Province Key Laboratory of Sustained Utilization&Development of Water Recourse,Hebei Province Collaborative Innovation Center for Sustainable Utilization of Water Resources and Optimization of Industrial Structure,Hebei Center for Ecological and Environmental Geology Research,School of Water Resource and Environment,Hebei Geo University,Shijiazhuang 050031,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2023年第6期2101-2110,共10页
Journal of Safety and Environment
基金
国家自然科学基金项目(21906039)
中央高校基本科研业务项目(300102292903,300102292601)。
