摘要
通过水热法开发了一种负载生物炭的富氧空位溴氧化铋复合光催化剂(BC/OV-BiOBr,BOVB),以四环素(TC)为目标污染物考察其光催化性能,同时以染料类污染物对催化效果进行验证分析.结果表明,最佳配比的BOVB复合物在可见光下60min内对TC的去除率达到99.8%,40min内即可实现对罗丹明B(RhB)的完全降解,降解速率分别是纯BiOBr的8.92倍和9.82倍.污染物降解过程对酸碱度变化和低浓度共存离子具有较强的抗性.物相表征和光电化学性能测试结果表明,添加生物炭使材料形貌由片状向花状转变,并提高氧空位浓度,有利于提高光响应能力､加速电荷转移.活性物种捕获及产量实验证明,生物炭与氧空位在驱动自由基链式反应方面具有协同作用,提高体系中超氧自由基(·O_(2)^(-))浓度的同时,将其进一步转化为羟基自由基(·OH),为污染物降解提供丰富的强氧化活性物种.此外,所得催化剂在连续5次降解实验中表现出良好的循环稳定性.
A composite photocatalyst of bismuth oxybromide with oxygen vacancies covered by biochar(BC/OV-BiOBr,BOVB)was developed by hydrothermal method.Its photocatalytic performance was investigated with tetracycline(TC)as the target pollutant,and the catalytic effect was verified by dye pollutants.The results showed that 99.8%of tetracycline(TC)and 100%Rhodamine B(RhB)could be decomposed within 60min or 40min under visible light,of which degradation rates were 8.92 times and 9.82 times that of pure BiOBr,respectively.The degradation process of pollutants had strong resistance to pH change and low concentration co-existing ions.The results of phase characterization and photoelectrochemical performance test showed that the morphology was changed from flake to flower and the concentration of oxygen vacancies was increased after adding biochar,which were beneficial to improve the photoresponse and accelerate the charge transfer.Due to the synergistic effect between biochar and oxygen vacancies in driving the free radical chain reaction,the concentration of superoxide free radical(·O_(2)^(-))in the system was increased,which was further transformed it into hydroxyl free radical(·OH),providing abundant strong oxidizing active species for pollutant degradation.In addition,good cyclic stability was certified by 5consecutive degradation experiments.
作者
于瀚博
陈凝露
李奥祥
胡炜
李业旺
冀雪婷
陈艾昕
赵宇
熊婷
YU Han-bo;CHEN Ning-lu;LI Ao-xiang;HU Wei;LI Ye-wang;JI Xue-ting;CHEN Ai-xin;ZHAO Yu;XIONG Ting(School of Hydraulic and Environmental Engineering,Changsha University of Science&Technology,Changsha 410114,China;Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province,Changsha 410114,China;School of Advanced Interdisciplinary Studies,Hunan University of Technology and Business,Changsha 410205,China)
出处
《中国环境科学》
北大核心
2025年第1期310-321,共12页
China Environmental Science
基金
湖南省自然科学基金资助项目(2022JJ40503)
湖南省青年骨干教师资助计划。
关键词
光催化
溴氧化铋
生物炭
氧空位
四环素
自由基链式反应
photocatalysis
bismuth oxybromide
biochar
oxygen vacancies
tetracycline
free radical chain reaction
