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

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

作　　者：Tingting Hu Panpan Feng Hongqi Chu Teng Gao Fusheng Liu Wei Zhou 胡婷婷;冯盼盼;褚宏旗;高腾;刘福胜;周卫(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;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;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)

机构地区：[1]State Key Laboratory Base for Eco-Chemical Engineering,College of Chemical Engineering,Qingdao University of Science and Technology,Qingdao 266042,Shandong,China [2]Shandong Provincial Key Laboratory of Molecular Engineering,School of Chemistry and Chemical Engineering,Qilu University of Technology(Shandong Academy of Sciences),Jinan 250353,Shandong,China [3]School of Chemistry and Pharmaceutical Engineering,Shandong First Medical University&Shandong Academy of Medical Sciences,Jinan 250117,Shandong,China

出　　处：《Chinese Journal of Catalysis》2025年第2期123-134,共12页催化学报(英文)

基　　金：国家自然科学基金(52172206);山东省自然科学基金(ZR2023QB110,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(2023RCKY099,2024RCKY018);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。

摘　　要：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.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)@BiOCIS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BiOCI,能够有效吸收太阳能并展现出优异的氧化还原性能.将BiOCI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)@BiOCI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BiOCI的下半部分则捕获这些电子,Ti-CI键区对电子的吸引力导致了C1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BiOCI下半层内的差分电荷分布范围,该过程与从MIL-125(Ti)到BiOCI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�

关 键 词：Photocatalysis Built-in electric field Metal-organic framework BiOCl Ligand defect 

分 类 号：O643.3[理学—物理化学]