Home Products Cited in Publications Worldwide Imine Reversal Mediates Charge Separation and CO2 Photoreduction in Covalent Organic Frameworks
Daniel Streater; Denan Wang; Christian Fiankor; Eric Kennehan; Daohua Liu; Kevin Kohlstedt; Long Luo; Jian Zhang; Jier Huang
DOI:10.21203/rs.3.rs-1554507/v1
We investigate the correlation between CO2 reduction performance in twin COFs with reversed imine connectivity and reveal that imine-linkage imparts intramolecular charge transfer (ICT) directionality – an effect we term an “ICT Tesla Valve.” This reversal also affects the coordination of Re molecular catalyst (MC) and leads to a slowdown in light driven CO2→CO photoreduction. ICT towards Re MC in Re-f-COF facilitates efficient CO2 photoreduction while performance is reduced when ICT is direct away from Re MC in Re-r-COF. Combining theory with experimental data shows that ICT directionality affects the charge separation mechanism which is particularly evident in the much longer-lived excited state of Re-f-COF compared to Re-r-COF. These findings are unprecedented, revealing not only that the linker chemistry should be recognized as a key factor to consider in the development of COF photocatalysts but also provides a unique approach to tailor photocatalysts by controlling the direction of ICT.