Directional Electron Pumping at a Tailored Organic D-A Interface: Fueling Perylene Diimide Dianion (P2-) Mediated Efficient Photocatalytic CO2 Conversion

Facilitating the generation and stabilization of the perylene diimide dianion (P2-) is essential to overcome the intrinsic reduction limitations of neutral perylene diimide (P) for efficient CO2 conversion. In this work, a novel organic heterostructure was constructed by integrating the electron-donating 1, 3, 6, 8, - tetraphenylpyrene (T) with the electron-accepting perylene diimide, forming a tailored Donor-Acceptor (D-A) interface through π-π stacking and charge-transfer interactions. This D-A interface enables directional “electron pumping” from the donor (T) to the acceptor (P), significantly promoting charge carrier separation. Crucially, this sustained electron flux facilitates the generation and stabilization of the potent reductant P2-, endowing the system with superior reduction capability. This strategy of interfacial charge manipulation directly addresses the core challenge. Consequently, the P2--mediated system achieves enhanced CO2-to-CO photoconversion with a high rate of 1316.25 μmol g-¹ h-¹ and remarkable selectivity of 96.5%. This work underscores the pivotal role of stabilized P2- in efficient artificial photosynthesis and demonstrates the power of rational molecular design via organic D-A interfaces to achieve high-performance photocatalytic CO2 reduction through targeted electron transfer.