催化学报 ›› 2025, Vol. 69: 123-134.DOI: 10.1016/S1872-2067(24)60171-3

• 论文 • 上一篇    下一篇

缺陷型介孔MIL-125(Ti)@BiOCl S 型异质结中内建电场的调控机制及光催化性能研究

胡婷婷a,b, 冯盼盼c,*(), 褚宏旗b,*(), 高腾b, 刘福胜a,*(), 周卫b,*()   

  1. a青岛科技大学化学工程学院, 生态化工国家重点实验室, 山东青岛 266042
    b齐鲁工业大学(山东科学院)化学与化工学院, 分子工程山东省重点实验室, 山东济南 250353
    c山东第一医科大学和山东医学科学院, 化学与制药工程学院, 山东济南 250117
  • 收稿日期:2024-08-24 接受日期:2024-10-15 出版日期:2025-02-18 发布日期:2025-02-10
  • 通讯作者: 电子信箱: zwchem@hotmail.com (周卫), Fpanpanlhz@163.com (冯盼盼), hqchu@qlu.edu.cn (褚宏旗), liufusheng63@sina.com (刘福胜).
  • 基金资助:
    国家自然科学基金(52172206);山东省自然科学基金(ZR2023QB110);山东省自然科学基金(ZR2024MB155);齐鲁工业大学(山东省科学院)科教产融合示范项目基础研究项目(2023PX108);齐鲁工业大学(山东省科学院)人才研究项目(2023RCKY099);齐鲁工业大学(山东省科学院)人才研究项目(2024RCKY018);泰山学者专项基金和山东省高等学校青年创新团队发展计划

Revealing the regulatory mechanism of built-in electric field in defective mesoporous MIL-125(Ti)@BiOCl S-scheme heterojunctions toward optimized photocatalytic performance

Tingting Hua,b, Panpan Fengc,*(), Hongqi Chub,*(), Teng Gaob, Fusheng Liua,*(), Wei Zhoub,*()   

  1. aState Key Laboratory Base for Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong, China
    bShandong Provincial Key Laboratory of Molecular Engineering, School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, Shandong, China
    cSchool of Chemistry and Pharmaceutical Engineering, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250117, Shandong, China
  • Received:2024-08-24 Accepted:2024-10-15 Online:2025-02-18 Published:2025-02-10
  • Contact: E-mail: zwchem@hotmail.com (W. Zhou), Fpanpanlhz@163.com (P. Feng), hqchu@qlu.edu.cn (H. Chu), liufusheng63@sina.com (F. Liu).
  • Supported by:
    National Natural Science Foundation of China(52172206);Natural Science Foundation of Shandong Province(ZR2023QB110);Natural Science Foundation of Shandong Province(ZR2024MB155);Basic Research Projects for the Pilot Project of Integrating Science and Education and Industry of Qilu University of Technology (Shandong Academy of Sciences)(2023PX108);Talent Research Project of Qilu University of Technology (Shandong Academy of Sciences)(2023RCKY099);Talent Research Project of Qilu University of Technology (Shandong Academy of Sciences)(2024RCKY018);and the Special Fund for Taishan Scholars Project and the Development Plan of Youth Innovation Team in Colleges and Universities of Shandong Province

摘要:

太阳能驱动的光催化技术被视为一种有前景的可再生能源转化方式, 能够有效解决能源危机和环境污染问题. 然而, 光催化反应中光生载流子的快速复合现象严重限制了光能的转化效率, 影响了光催化技术的广泛应用. 为了解决该问题, 研究者们提出了异质结构工程的概念, 通过调节能带对齐、空间电荷分离和电子传输等因素来优化光催化性能. 内建电场(IEF)的构建被认为是促进光生载流子分离和传输的重要手段. 内建电场(IEF)的存在能够为载流子的迁移提供驱动力, 从而提高光催化剂的效率. 因此, 如何有效构建和调节IEF成为了光催化领域的重要研究方向.

本文成功设计构建了一种新型的MIL-125(Ti)@BiOCl S型异质结, 采用绿色光还原反应实现了对IEF的调控. MIL-125(Ti)是一种典型的钛金属有机框架, 其结构中的Ti4+具有强大的氧化还原能力, 但对可见光的利用有限. 相对而言, 铋基半导体材料如BiOCl, 能够有效吸收太阳能并展现出优异的氧化还原性能. 将BiOCl构建在MIL-125(Ti)上不仅整合了两者的结构与活性位点优势, 还通过界面电荷重组产生了IEF, 为光生载流子的分离和传输提供了驱动力. X射线光电子能谱、紫外可见漫反射光谱、Zeta电位和开尔文探针测试等结果证实了MIL-125(Ti)@BiOCl异质结的能带结构, IEF强度可以通过调节MIL-125(Ti)中的配位缺陷数量来精确控制, 从而优化了能带结构. 密度泛函理论(DFT)计算结果进一步证实了MIL-125(Ti)层释放电子, 而BiOCl的下半部分则捕获这些电子, Ti‒Cl键区对电子的吸引力导致了Cl原子沿键轴方向的部分电子损失. 配体缺陷的引入, 不仅没有破坏MOF结构的稳定性, 反而扩大了BiOCl下半层内的差分电荷分布范围, 该过程与从MIL-125(Ti)到BiOCl层的电子转移量的增加密切相关, 揭示了配位缺陷在促进两相之间电荷转移中的重要作用. 此外, 静电势差值的变化规律证明了MIL-125(Ti)层中配体缺陷明显影响了IEF的强度. 因此, DFT与实验结果确认了微结构通过IEF调节催化活性的机制, 进一步验证了材料中IEF的可控模式. 此外, 研究发现, 通过调节IEF, 可以显著提升光催化剂的光催化降解性能, 如在MIL-125(Ti)@BiOCl异质结中, 优化的IEF显著增强了光生载流子的分离和传输能力, 从而提高了对四环素的光催化降解性能, 其半小时内降解率可达到96.9%, 反应速率常数为0.091 min−1, 分别是BiOCl和MIL-125(Ti)-3的5.5和4.7倍. 这些发现为调控MOF基异质结中的IEF提供了新的途径, 为理解缺陷结构、IEF和光催化活性之间的内在联系提供了新的见解.

综上所述, 本研究提出的通过结构缺陷设计可控IEF为深入理解结构如何影响光催化性能提供了新思路. 通过调节缺陷结构、IEF与光催化活性之间的内在关联, 为未来光催化剂的设计与应用提供了重要的理论基础和实验支持. 本文不仅丰富了光催化领域的研究内容, 也为实现高效的光催化剂提供了新的方向.

关键词: 光催化, 内建电场, 金属有机框架, BiOCl, 配体缺陷

Abstract:

The rational configuration of built-in electric field (IEF) in heterogeneous materials can significantly optimize the band structure to accelerate the separation of photogenerated charge carriers. However, the strength modulation of IEF formed by various materials has an uncertain enhancing effect on the separation of photogenerated carriers. Herein, a mesoporous MIL-125(Ti)@BiOCl S-scheme heterojunction with controllable IEF is prepared by green photoreduction reaction to investigate the relationship between IEF, microstructure, and photocatalytic activity. Moreover, the corresponding results demonstrate the MIL-125(Ti)@BiOCl effectively regulates the IEF strength through controlling the concentration of ligand defects, thereby optimizing the band structure and improving the efficiency of photogenerated charge separation. The optimized IEF significantly enhances the photocatalytic degradation performance of mesoporous MIL-125(Ti)-3@BiOCl towards tetracycline, with a k value of 0.07 min−1, which are approximately 5.5 and 4.7 times greater than that of BiOCl (0.0127 min−1) and MIL-125(Ti)-3 (0.015 min−1). These findings provide a new pathway for regulating IEF within MOF-based heterojunctions, and offer new insights into the intrinsic correlations between defect structure, IEF, and photocatalytic activity.

Key words: Photocatalysis, Built-in electric field, Metal-organic framework, BiOCl, Ligand defect