催化学报 ›› 2020, Vol. 41 ›› Issue (10): 1511-1521.DOI: 10.1016/S1872-2067(19)63525-4

• 论文 • 上一篇    下一篇

·CO3-在基于太阳光驱动的TiO2-贝壳粉降解盐酸四环素中的作用:降解机理和转化路径

王佳琦a, 钱庆荣a, 陈庆华a,b, 刘欣萍a, 罗永晋a, 薛珲a, 李朝晖c   

  1. a 福建师范大学环境科学与工程学院, 福建省污染控制与资源循环利用重点实验室, 福建福州 350007;
    b 福建师范大学福清分校, 福建福清 350007;
    c 福州大学化学学院, 能源与环境光催化国家重点实验室, 福建福州 350116
  • 收稿日期:2020-01-26 修回日期:2020-03-03 出版日期:2020-10-18 发布日期:2020-08-15
  • 通讯作者: 薛珲, 李朝晖
  • 基金资助:
    国家自然科学基金(21875037,51502036);国家重点研发计划(2016YFB0302303).

Significant role of carbonate radicals in tetracycline hydrochloride degradation based on solar light-driven TiO2-seashell composites: Removal and transformation pathways

Jiaqi Wanga, Qingrong Qiana, Qinghua Chena,b, Xin-Ping Liua, Yongjin Luoa, Hun Xuea, Zhaohui Lic   

  1. a College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control&Resource Reuse, Fujian Normal University, Fuzhou 350007, Fujian, China;
    b Fuqing Branch of Fujian Normal University, Fuqing 350300, Fujian, China;
    c State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350116, Fujian, China
  • Received:2020-01-26 Revised:2020-03-03 Online:2020-10-18 Published:2020-08-15
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21875037, 51502036), and the National Key R&D Program of China (2016YFB0302303).

摘要: 抗生素的滥用和不当排放对水陆生生态系统造成了严重威胁,在世界各地水环境污染物调研中普遍检测到盐酸四环素的存在.如何解决水体中高稳定、难降解的盐酸四环素污染问题是当前环境领域重点研究的课题之一.在各种去除方法中,利用光化学反应生成活性氧物种如·CO3-,·OH,·O2-,·SO4-1O2等实现对有机污染物的降解在众多研究方法中脱颖而出.·CO3-在水体中具有较高的稳态浓度且其对有机物降解具有高选择性.CO32-或HCO3-与活性物种如·OH,h+,·O2-,·SO4-等反应可以生成·CO3-.传统的半导体光催化剂TiO2在光照下会产生·OH,·O2-及h+等活性物种,能有效地降解有机污染物,已有研究发现添加CO32-/HCO3-有利于提高UV/TiO2体系降解有机物的反应速率.
贝壳中含有95%以上的碳酸钙,由于其具有低成本、生态友好、无毒性等特点而越来越受到人们的关注.贝壳与TiO2复合,利用贝壳在水相中提供的CO32-/HCO3-与TiO2在光照下产生的·OH,·O2-及h+等活性物种反应生成·CO3-促进光催化反应速率的提高,对盐酸四环素的有效去除具有显著意义.
本文通过溶胶-凝胶法合成TiO2-贝壳粉,采用X射线衍射、扫描电子显微镜、透射电子显微镜、X射线光电子能谱、红外光谱和氮气吸附-脱附测试等技术对所得样品进行了表征.考察了TiO2-贝壳粉在模拟太阳光下对盐酸四环素的降解性能.结果表明,在模拟太阳光的作用下,40% TS-300在30min内能降解94.0%的盐酸四环素,优于纯TiO2的降解效率(88.6%).通过自由基捕获实验比较了TiO2和TiO2-贝壳粉体系降解盐酸四环素机理的差异,在TiO2光催化降解盐酸四环素体系中,·O2-和h+是主要活性物种.而在TiO2-贝壳粉体系中,TiO2在光照条件下产生的·OH,·O2-及h+通过与贝壳粉在水相中提供的CO32-/HCO3-进一步产生·CO3-,·CO3-、·O2-和h+协同作用实现盐酸四环素的有效降解.采用HRESI-TOF-MS研究了40% TS-300光降解盐酸四环素的中间转化产物,提出TiO2-贝壳粉光降解盐酸四环素可能的降解路径.对40% TS-300样品进行了光降解盐酸四环素长效循环测试,结果表明该样品能够保持稳定有效的降解盐酸四环素性能,此为该材料今后的潜在应用奠定了可靠基础.

关键词: TiO2-贝壳粉, 碳酸根自由基, 光化学作用, 盐酸四环素, 机理

Abstract: TiO2-seashell composites prepared via a sol-gel method were used to generate carbonate radicals (·CO3-) under solar light irradiation.·CO3-, a selective radical, was employed to degrade the target tetracycline hydrochloride contaminant. A series of characterizations was carried out to study the structure and composition of the synthesized TiO2-seashell composite. This material exhibits excellent solar light-driven photochemical activity in the decomposition of tetracycline hydrochloride. The possible pathway and mechanism for the photodegradation process were proposed on the basis of high-resolution electrospray ionization time-of-flight mass spectrometry experiments. Finally, we investigated the reusability of the TiO2-seashell composite. This study is expected to provide a new facile pathway for the application of·CO3- radicals to degrade special organic pollutants in water.

Key words: TiO2-seashell, Carbonate radical, Photochemistry, Tetracycline hydrochloride, Mechanism