Structure Engineered Quantum Dots Couple CO ₂ Reduction With Vicinal Diamines Production in a Single Photoredox Cycle

Abstract

ABSTRACT Photocatalytic CO 2 reduction coupled with organic transformations has attracted significant attention as a promising strategy for efficient solar energy utilization. However, challenges remain, particularly when it comes to achieving high selectivity in CO 2 reduction and further expanding the diversity of oxidative organic transformations. Herein, by subtly engineering the structure of CdSe/CdS quantum dots (QDs), we report the integration of photocatalytic CO 2 reduction with vicinal diamines production via oxidative C–C coupling of amines in a single photoredox cycle under visible light. Dynamic experiments indicate the photogenerated electrons for reducing CO 2 proceed in coordination with photogenerated holes oxidizing amines, thus realizing vicinal diamines with yields up to 97% and CO 2 ‐to‐CO conversion with selectivity as high as 98%. Mechanistic studies indicate that controlled QD structural engineering optimizes exciton dynamics by balancing electron and hole trapping, ensuring efficient charge separation and utilization. The system is applicable to a range of amine substrates and usable for gram‐scale vicinal diamines synthesis, underscoring its potential for synergistic CO 2 valorization and valuable chemicals production.