Constructing electron delocalization channels in covalent organic frameworks powering CO2 photoreduction in water

By Yonggang Xiang, W. Dong, Pei Wang, Shengyao Wang, Xing Ding, Fumihiko Ichihara, Zhuan Wang, Y. Wada, Shangbin Jin, Y. Weng and 2 more. 2020

141 citations recorded by the source corpus.

Abstract The photocatalytic conversion of CO2 into chemical fuels represents a promising approach for solving the future energy crisis. However, the construction of a photocatalyst simultaneously integrating a photosensitizer and molecular cocatalyst with intramolecular electron delivery is challenging. Herein, we designed covalent organic frameworks (COFs) with excellent extended conjugation and potential embedded redox active sites. The full -C = C- bridging in sp2c-COFdpy creates and dredges the donor-acceptor channel for intramolecular electron delocalization and a cascade effect. Interestingly, CO2 photoreduction can be carried out in water, and the optimized sp2c-COFdpy-Co exhibits the highest activity and stability among COFs without noble metal involvement, achieving up to 17.93 mmol g−1 CO with 81.4 % selectivity in a long-range reaction. Theoretical calculations and experimental data suggest that the structural advantages enable excitons to facilely reach single Co sites via the electron cascade, which provides a new concept in the nanoarchitecture of COFs for efficient CO2 photoreduction.

Subfields: Inorganic Chemistry, Materials Chemistry, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/d994333c26e8ef93bebf523c06b1e391638ef9f8