Regulating π–π Stacking Interactions to Boost Near‐Infrared Light‐Driven CO ₂ Reduction

ABSTRACT Developing highly efficient photocatalysts to achieve near‐infrared (NIR) light‐driven CO 2 reduction is of great significance yet remains a great challenge. In this article, we found that BODIPY‐based π frameworks can serve as good NIR photocatalysts, achieving highly efficient CO 2 reduction to HCOO − coupled with benzyl alcohol oxidation to benzaldehyde in pure water. More impressively, the photocatalytic performance of these π frameworks can be improved by regulating π–π stacking interactions, among which the optimized π‐pyrenyl (π‐PY) framework with the most π–π stacking interactions exhibits HCOO − production rates of 4045 and 1693 µmol g −1 h −1 in >99% and 15% CO 2 atmospheres, respectively. π‐PY, thus, stands for the current state‐of‐the‐art photocatalyst in NIR‐light‐driven CO 2 reduction. Experiments together with theoretical calculations demonstrated that the high photocatalytic activity of π‐PY could be due to the abundant π–π stacking interactions, which accelerates charge separation and transfer, as well as prolongs carrier lifetime and reduces energy gap. This work gives new insights in understanding the contribution of π–π stacking interactions to photocatalysis, and introduces a new strategy for developing efficient photocatalysts for NIR‐light‐driven CO 2 reduction.