Abstract The rapid accumulation of atmospheric carbon dioxide (CO 2 ) from anthropogenic activities presents an urgent challenge for sustainable energy conversion. Designing efficient organic semiconductors for photocatalytic CO 2 reduction is hindered by the intricate coupling between molecular structure, supramolecular assembly, and charge‐transfer dynamics. Here, we present a systematic imide‐site functionalization strategy for perylene diimide (PDI), introducing carboxyl, urea, amino, and imidazole groups to regulate supramolecular stacking and optoelectronic properties. Among these derivatives, PDI‐COOH delivers a superior CO evolution rate of 12.78 μmol g −1 , representing a seven‐fold enhancement over pristine PDI, coupled with exceptional long‐term photostability. Structural analyses reveal that carboxyl functionalization promotes highly ordered one‐dimensional nanorod assemblies via optimized intermolecular hydrogen bonding, leading to bandgap narrowing and accelerated charge separation. Density functional theory calculations further demonstrate that PDI‐COOH exhibits a downshifted conduction band, enhanced electronic delocalization, and a reduced energy barrier for *COOH formation, favoring a two‐electron CO 2 reduction pathway. In situ Fourier‐transform infrared spectroscopy identifies *COOH as the key intermediate, corroborating the theoretical predictions. This work underscores the pivotal role of precise imide‐site functionalization in tuning the intrinsic redox potential and surface basicity of organic catalysts, providing a theoretical framework for the development of high‐performance, metal‐free systems for sustainable solar‐to‐fuel conversion.
Luo et al. (Mon,) studied this question.