高等学校化学学报 ›› 2024, Vol. 45 ›› Issue (12): 20240337.doi: 10.7503/cjcu20240337

• 研究论文: 无机化学 • 上一篇    下一篇

pH介导铜络合物活化过一硫酸盐选择性氧化水体四环素的分子内电子转移机制

曾湘楚1,2, 叶雨婷1,2, 武哲1,2, 韦瑞松1,2(), 刘欢3   

  1. 1.河池学院化学与生物工程学院, 广西现代蚕桑丝绸协同创新中心
    2.广西蚕桑生态学与智能化技术应用重点实验室, 河池 546300
    3.西安市生态环境局, 西安 710000
  • 收稿日期:2024-07-05 出版日期:2024-12-10 发布日期:2024-09-11
  • 通讯作者: 韦瑞松 E-mail:wrs1708@sina.com
  • 基金资助:
    中国博士后科学基金(2024M751271);广西现代蚕桑丝绸协同创新中心基金(2023GXCSSC03);2023年度广西高校中青年教师科研基础能力提升项目(2024KY0623);河池学院高层次人才科研启动项目(2023GCC015);2023年河池市本级财政科技计划项目(批准号: 河科AC231107)资助

Intramolecular Electron Transfer Mechanism of pH-Mediated Cupric Complexes Activated Peroxymonosulfate Selective Oxidation of Aqueous Tetracycline

ZENG Xiangchu1,2, YE Yuting1,2, WU Zhe1,2, WEI Ruisong1,2(), LIU Huan3   

  1. 1.Guangxi Collaborative Innovation Center of Modern Sericulture and Silk
    2.Guangxi Key Laboratory of Sericulture Ecology and Applied Intelligent Technology,School of Chemistry and Bioengineering,Hechi University,Hechi 546300,China
    3.Xi’an Ecological Environment Bureau,Xi’an 710000,China
  • Received:2024-07-05 Online:2024-12-10 Published:2024-09-11
  • Contact: WEI Ruisong E-mail:wrs1708@sina.com
  • Supported by:
    the China Postdoctoral Science Foundation(2024M751271);the Special Project of Guangxi Collaborative Innovation Center of Modern Sericulture and Silk, China(2023GXCSSC03);the 2023 Guangxi University Young and Middle-aged Teachers Research Basic Ability Improvement Project, China(2024KY0623);the Hechi University High-level Talent Research Project, China(2023GCC015);the 2023 Hechi City Level Financial Science and Technology Plan Project, China(HekeAC231107)

摘要:

虽然水中游离的Cu(Ⅱ)无法有效活化过一硫酸盐(PMS), 但与四环素(TC)络合形成的铜络合物则具有活化PMS自催化降解TC的作用. 紫外-可见分光光谱和高效液相色谱分析结果验证了Cu(Ⅱ)-TC混合溶液中铜络合物的形成; 密度泛函理论(DFT)计算结果揭示了铜络合物形成的反应路径、 分子结构模型、 自由能变、 态密度(DOS)和络合作用力. 研究发现, Cu(H2O)42 +中Cu的 d轨道接受TC中羟基、 羰基及酰胺基中O的 p轨道孤对电子形成络合物. 构筑的5种可能的络合形式均呈现稳定的二配位六元环状结构. 其中, 形成络合物M1的自由能变最小、 结构最稳定. 铜络合物形成的作用力主要为范德华力、 弱相互作用、 共价键、 空间位阻及配位键等. Cu(II)/PMS体系对TC具有显著的自催化降解作用, 在240 min内可以完全降解(降解率>99%); 并且在碱性(pH=10)条件下, Cu(Ⅱ)络合物活化PMS原位生成Cu(III)络合物的分子内电子转移过程主导了TC的选择性氧化. 通过DFT计算从动态、 微观视角进一步阐明了pH介导铜络合物活化PMS选择性氧化水体TC的分子内电子转移机制.

关键词: 铜络合物, 过一硫酸盐, 四环素, 选择性氧化

Abstract:

Although aqueous dissociative Cu(Ⅱ) could not effectively activate peroxymonosulfate(PMS), the cupric complexes formed by complexing with tetracycline(TC) could activate PMS and realize self-catalytic degradation of TC. The generation of cupric complexes was verified by UV-Vis and high performance liquid chromatography(HPLC), and the reaction pathways, molecular structure model, free energy variation, density of states(DOS), and complexation interaction of cupric complexes were revealed by density functional theory(DFT) calculation. It was found that the d orbital of Cu in Cu(H2O)42 + was complexed by accepting the lone pair electrons of p orbital from hydroxyl, carbonyl, and amide group O in TC, and there were five possible complexation models constructed, all of them showed a stable bidenate ligands and hexatomic-ring coordination structure, in which the free energy of complex M 1 became the smallest and its structure was the most stable. The interaction of cupric complexes formation mainly included van der Waals force, weak interaction, covalent bond, steric hindrance, coordination bond, etc. Cu(II)/PMS system had significant self-catalytic degradation of TC, which could be completely degraded within 240 min(degradation efficiency was greater than 99%). Furthermore, under alkaline conditions(pH=10), the activation of peroxymonosulfate by cupric complexes coupling Cu(III) complexes generation in situ promoted an intramolecular electron transfer(IET) process dominating the selective oxidation of TC. The pH-mediated IET mechanism of cupric complexes activated peroxymonosulfate selective oxidation of aqueous tetracycline was further elucidated through DFT calculations from dynamic and microscopic perspectives. The new findings in this paper further verified the self-catalytic selective oxidation performance and mechanism by aqueous cupric complexes activated PMS system, which provided a potential solution for the synergistic decontamination of actual wastewater contaminated heavy metals and antibiotics.

Key words: Cupric complex, Peroxymonosulfate, Tetracycline, Selective oxidation

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