催化学报 ›› 2023, Vol. 47: 171-180.DOI: 10.1016/S1872-2067(23)64397-9

• 论文 • 上一篇    下一篇

具有可控载流子动力学的烯烃连接的共价有机框架用于高效太阳能光催化制氢

解志鹏a,1, 杨修贝b,1, 张沛b, 柯夏婷a, 袁昕b, 翟黎鹏b,*(), 王文滨a, 秦娜b, 崔乘幸c,*(), 屈凌波d, 陈雄a,*()   

  1. a福州大学化学学院, 能源与环境光催化国家重点实验室, 有机合成与功能福建省高校重点实验室, 福建福州350116
    b中原工学院先进材料研究中心, 河南省功能盐材料重点实验室, 河南郑州450007
    c河南科技学院化学化工学院, 河南新乡453003
    d郑州大学化学学院和绿色催化中心, 河南郑州450001
  • 收稿日期:2022-10-19 接受日期:2023-01-16 出版日期:2023-04-18 发布日期:2023-03-20
  • 通讯作者: *电子信箱: zhailp@zut.edu.cn (翟黎鹏),chengxingcui@hist.edu.cn (崔乘幸),chenxiong987@fzu.edu.cn (陈雄).
  • 作者简介:1共同第一作者.
  • 基金资助:
    国家自然科学基金(21972021);国家自然科学基金(52103277);河南科技攻关(212102210208);河南科技攻关(202102210054);河南科技攻关(212102210442);中原工学院启动基金项目(K2020YY001)

Vinylene-linked covalent organic frameworks with manipulated electronic structures for efficient solar-driven photocatalytic hydrogen production

Zhipeng Xiea,1, Xiubei Yangb,1, Pei Zhangb, Xiating Kea, Xin Yuanb, Lipeng Zhaib,*(), Wenbin Wanga, Na Qinb, Cheng-Xing Cuic,*(), Lingbo Qud, Xiong Chena,*()   

  1. aState Key Laboratory of Photocatalysis on Energy and Environment, Key Laboratory of Molecule Synthesis and Function Discovery (Fujian Province University), College of Chemistry, Fuzhou University, Fuzhou 350116, Fujian, China
    bHenan Key Laboratory of Functional Salt Materials, Center for Advanced Materials Research, Zhongyuan University of Technology, Zhengzhou 450007, Henan, China
    cSchool of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang 453003, Henan, China
    dCollege of Chemistry, and Institute of Green Catalysis, Zhengzhou University, Zhengzhou 450001, Henan, China
  • Received:2022-10-19 Accepted:2023-01-16 Online:2023-04-18 Published:2023-03-20
  • Contact: *E-mail: zhailp@zut.edu.cn(L. Zhai),chengxingcui@hist.edu.cn(C.-X. Cui),chenxiong987@fzu.edu.cn (X. Chen).
  • About author:1Contributed equally to this work.
  • Supported by:
    National Natural Science Foundation of China(21972021);National Natural Science Foundation of China(52103277);Key Projects of Science and Technology of Henan Province(212102210208);Key Projects of Science and Technology of Henan Province(202102210054);Key Projects of Science and Technology of Henan Province(212102210442);Zhongyuan University of Technology Start-Up Grant and the Independent Innovation Application Research Project(K2020YY001)

摘要:

太阳能光催化水直接制氢被认为是未来解决全球能源危机和环境污染问题的有效途径之一. COFs是一类新兴的有机结晶多孔聚合物光催化剂, 具有巨大的发展空间. 当前研究最多的是亚胺键连接的COFs光催化剂, 其骨架的π-共轭程度相对较低, 且亚胺键上的氮容易受到质子攻击, 会影响光化学过程和光催化性能. 烯烃(C=C键)连接的COFs是全π-共轭的, 具有促进的载流子迁移率和超高的化学稳定性, 是极具潜力的光催化反应平台. 然而, 由于C=C键的不可逆特性, 成功构筑具有高结晶度和孔隙率的烯烃连接的COFs仍极具挑战. 构建D-A结构被认为是提升其光催化活性的有效策略之一, 但目前具有D-A结构的烯烃连接的COFs光催化研究较少.

本文提出了一种简单的分子工程策略来调控烯烃连接COFs的D-A相互作用以实现高效的光催化产氢. 将2,4,6-三甲基1,3,5-三嗪(TM)分别与对苯二甲醛(TA)、2,5-二甲基对苯二甲醛(MA)和3,3’-二甲基-4,4’-二醛基联苯(DMA)通过Knoevenagel聚合反应制备三种D-A型烯烃连接的COFs, 即TM-TA-COF, TM-MA-COF和TM-DMA-COF, 系统考察了引入甲基和苯环等较弱电子给体对光催化析氢性能的影响. 结果发现, 当将电子基团锚定在框架中时, 可提供不同程度的D-A相互作用力, 从而精准调控COFs光催化剂的激子解离效率、电荷传输行为、光响应能力和HOMO-LUMO水平, 优化COFs的光催化产氢活性. 傅里叶红外光谱、固体核磁和X射线光电子能谱证明了三种COFs材料的成功合成. 粉末X射线衍射和氮气吸脱附结果表明, 三种COFs具有良好的结晶性和高孔隙率(比表面积分别为911, 747和1021 m2 g‒1). 光物理测试结果表明, 三种COFs都具有可见光响应能力和合适的导带位置以驱动可见光光催化分解水产氢, 且光生载流子的复合程度和激子结合能随着给体共轭程度的增强而降低, 其中TM-DMA-COF具有最优的载流子分离能力. 光催化分解水产氢结果表明, TM-DMA-COF具有最高的产氢活性, 可达4300 µmol h‒1 gcat‒1, 高于大多数COFs光催化剂的析氢性能, 与预测结果一致. 光(电)化学测试结果表明, TM-DMA-COF表现出最高产氢催化活性, 这与其具有最佳的电荷转移动力学以及最强的与Pt助催化剂相互作用力有关. 理论研究结果表明, D-A相互作用随着给体共轭程度的提高而增强, 这有利于载流子动力学以及降低H2形成的能量势垒, 最终提升光催化活性.

综上, 本文制备了三种具有高结晶度和孔隙率的D-A型烯烃连接COFs, 以阐述甲基和苯环等相对较弱的给电子基团在COFs光催化剂结构设计中的价值, 为调节COFs的光催化性能提供了一种新的简单有效的策略.

关键词: 共价有机框架, 光催化产氢, 烯烃连接, 多孔材料, 给体受体

Abstract:

Vinylene-linked covalent organic frameworks (COFs) are promising photocatalysts owing to their fully conjugated skeletons that facilitate charge carrier mobility. Constructing donor-acceptor (D-A) architectures could further enhance photoinduced charge generation and transport, thus promoting photocatalysis. Therefore, three D-A-type vinylene-linked COFs were fabricated via Knoevenagel polymerization for efficient photocatalysis. By varying the donor moieties from phenyl to 2,5-dimethylbenzene and 3,3'-dimethyl-1,1'-biphenyl in the skeletons, the light-harvesting, optical-bandgap, and charge-transfer properties of the COFs were precisely regulated. All three COFs exhibited attractive photocatalytic hydrogen evolution rates (HERs) upon visible-light irradiation, especially that fabricated using 2,4,6-trimethyl-1,3,5-triazine (TM) and 3,3'-dimethyl[1,1'-biphenyl]-4,4'-dicarboxaldehyde (DMA, TM-DMA-COF). TM-DMA-COF exhibited the strongest D-A interactions, excellent charge-carrier separation and transfer kinetics, and a reduced energy barrier for H2 formation. Thus, it afforded the highest HER of 4300 µmol h‒1 gcat‒1, surpassing those of most state-of-the-art COF photocatalysts. This study provides a simple and effective protocol for modulating the photocatalytic activities of COFs at the molecular level and an interesting insight into the relationship between structural design and photocatalytic performance.

Key words: Covalent organic framework, Photocatalytic H2 generation, Olefin linkage, Porous polymer, Donor-acceptor