Outdoor sunlight driven CO2 capture and cycloaddition from flowing simulated industrial flue gas using amino functionalized bismuth catalysts

Sunlight driven conversion of CO 2 from industrial flue gas into value-added cyclic carbonates represents a promising carbon mitigation strategy, yet the dynamic modulation of Lewis base sites remains largely unexplored, often resulting in limited CO 2 utilization. In this work, we innovatively employed an amino functionalization strategy to graft tetraethylenepentamine onto Bi 4 NbO 8 Cl (BNOC-TEPA) for photocatalytic CO 2 cycloaddition. Using 1, 2-epoxybutane as a model substrate, BNOC-TEPA 30 delivers a 1, 2-butylene carbonate production rate of 10.41 mmol·g ‒1 ·h ‒1 , 2.88 times that of pristine BNOC. Combined experiments and DFT calculations reveal that terminal primary amines of TEPA serve as Lewis base sites to strengthen CO 2 adsorption and activation, while the abundant coordinated Bi sites act as Lewis acid centers to facilitate epoxide activation. Meanwhile, the asymmetric surface structure further induces local polarized electric fields, facilitating charge separation and transfer. Scaled-up outdoor experiments further demonstrated that simulated flue gas containing 15% CO 2 can be efficiently captured and directly converted, achieving a 1, 2-butylene carbonate production rate of 4.45 mmol·g ‒1 ·h ‒1 and showing great potential for industrial applicability. This work proposes a novel modification strategy that effectively promotes the integrated adsorption conversion process of low concentration CO 2 from industrial flue gases, opening a new avenue for the resource utilization of industrial carbon emissions. Herein, Tetraethylenepentamine (TEPA) was grafted onto Bi 4 NbO 8 Cl via post-synthetic amine functionalization, enabling the direct capture and conversion of low-concentration CO 2 (15%) from simulated flue gas into cyclic carbonates under ambient conditions and natural sunlight. • TEPA grafting and Bi–N coordination synergistically enhance Lewis basicity/acidity, enabling highly efficient photocatalytic CO 2 cycloaddition. • BNOC-TEPA 30 maintains high activity and selectivity in the presence of typical flue gas impurities, demonstrating strong impurity tolerance under realistic simulated flue gas conditions. • Scaled-up and outdoor sunlight experiments validate efficient solar-driven CO 2 cycloaddition using simulated flue gas.