Improving photosensitization for photochemical CO2-to-CO conversion

Ping Wang; Ru Dong; Song Guo; Jianzhang Zhao; Zhi-Ming Zhang; Tong-Bu Lu

doi:10.1093/nsr/nwaa112

Improving photosensitization for photochemical CO₂-to-CO conversion

Natl Sci Rev. 2020 May 28;7(9):1459-1467. doi: 10.1093/nsr/nwaa112. eCollection 2020 Sep.

Authors

Ping Wang¹, Ru Dong¹, Song Guo¹, Jianzhang Zhao², Zhi-Ming Zhang¹, Tong-Bu Lu¹

Affiliations

¹ MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China.
² State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.

Abstract

Inspired by nature, improving photosensitization represents a vital direction for the development of artificial photosynthesis. The sensitization ability of photosensitizers (PSs) reflects in their electron-transfer ability, which highly depends on their excited-state lifetime and redox potential. Herein, for the first time, we put forward a facile strategy to improve sensitizing ability via finely tuning the excited state of Ru(II)-PSs (Ru-1-Ru-4) for efficient CO₂ reduction. Remarkably, [Ru(Phen)₂(3-pyrenylPhen)]²⁺ (Ru-3) exhibits the best sensitizing ability among Ru-1-Ru-4, over 17 times higher than that of typical Ru(Phen)₃ ²⁺. It can efficiently sensitize a dinuclear cobalt catalyst for CO₂-to-CO conversion with a maximum turnover number of 66 480. Systematic investigations demonstrate that its long-lived excited state and suitable redox driving force greatly contributed to this superior sensitizing ability. This work provides a new insight into dramatically boosting photocatalytic CO₂ reduction via improving photosensitization.

Keywords: CO2 reduction; Ru(II) complexes; excited state; photocatalysis; photosensitization.