Acta Chimica Sinica ›› 2020, Vol. 78 ›› Issue (10): 1082-1088.DOI: 10.6023/A20070316 Previous Articles     Next Articles



孙静静, 吴仇荣, 翁文强, 刘晓勤, 谈朋, 孙林兵   

  1. 南京工业大学化工学院 材料化学工程国家重点实验室 南京 211816
  • 投稿日期:2020-07-16 发布日期:2020-08-12
  • 通讯作者: 孙林兵
  • 基金资助:

Smart Light-responsive CO2 Adsorbents for Regulating Strong Active Sites

Sun Jingjing, Wu Qiurong, Weng Wenqiang, Liu Xiaoqin, Tan Peng, Sun Linbing   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
  • Received:2020-07-16 Published:2020-08-12
  • Supported by:
    Project supported by the National Science Foundation for Excellent Young Scholars (No. 21722606), the National Natural Science Foundation of China (Nos. 21676138, 21878149, 21808110), and China Postdoctoral Science Foundation (No. 2019T120419).

Light-responsive CO2 adsorbents can effectively adjust their ability to capture CO2 through external light irradiation, and have the advantages of good controllability and high energy efficiency during the adsorption process. However, the currently reported light-responsive CO2 adsorbents can only realize the regulation of weak adsorption sites, and the regulation of strong adsorption sites is still a challenging task. In this work, a light-responsive smart adsorbent was constructed by in situ synthesis, and the light-responsive control of strong adsorption sites for CO2 was realized. The construction of adsorbent was achieved by introducing the azobenzene derivative with cis and trans isomers and silane coupling agent containing primary amines into mesoporous silica. The characterization results show that the adsorbents have uniform pore channels, and primary amine and light-responsive groups are dispersed on the pore walls. The strong interaction between primary amine and CO2 can lead to the selective adsorption of CO2, while azobenzene as a molecular switch can regulate the adsorption performance of primary amine. Before light irradiation, azobenzene is in trans configuration, which decreases the electrostatic potential of the primary amine, and exposes the active site, thus CO2 can be freely adsorbed; after light irradiation, azobenzene is converted to the cis configuration, which increases the electrostatic potential of the primary amine and shields the active sites. The change amount of adsorption capacity can reach 43%, and this process is reversible. Both the light-responsive properties of azobenzene groups and the adsorptive performances of adsorbents can be well maintained after 5 cycles. Azobenzene in different configuration has distinctive influences on the electrostatic potential of primary amine, thereby achieving the regulation of adsorption ability. This work utilizes the specific interaction between stimuli-responsive groups and target-specific adsorption sites, realizing the regulation of strong active cites for CO2, which gives clues to the development of new smart adsorbents.

Key words: CO2 adsorption, light-responsive switch, strong adsorption site, selective adsorption, smart adsorbent