Highly dispersed Co-modified covalent organic frameworks as bridging cocatalysts for boosting CO2 photoreduction over defective carbon nitride

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 11; no. 9; pp. 4572 - 4578
• Main Authors: Qiu, Jinyu, Zheng, Yanxia, Wang, Lanxin, Liu, Meng, Tian, Lintao, Yu, Xuelian, An, Xiaoqiang, Lv, Guocheng
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 27.02.2023
• Subjects: Carbon dioxide; Carbon nitride; Catalysts; Chelation; Electrons; Hydrogen evolution; Irradiation; Light irradiation; Noble metals; Photocatalysis; Photocatalysts; Photoreduction; Radiation; Selectivity
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d2ta09140b

It is still a great challenge to increase both the active sites and charge separation of earth-abundant catalysts for efficient and durable photocatalytic CO2 conversion. To achieve these aims, we designed imine-linked covalent organic frameworks as the electron bridge that links the photocatalyst and robust metal active sites for photocatalytic CO2 reduction. When integrated with defective g-C3N4, the composite generated 37.3 μmol h−1 of CO with 98.8% selectivity over H2 evolution under visible light irradiation, which greatly outperformed other non-noble metal species as cocatalysts. Experimental and theoretical results demonstrated that the stabilized Co ions with a six-membered chelating structure effectively improved the collection of excited electrons and stability of the catalyst. This study provides a new protocol to improve CO2 photoreduction performance through coupling defect-modulated photocatalysts with bridging cocatalysts.