Nearly 100% selective CO2 photoreduction to CO via Fe-modified amino acid-functionalized UiO-66

Photoreduction of carbon dioxide (CO 2 ) into useful carbon-based fuels is a promising strategy for reducing excessive CO 2 emissions and addressing the global energy crisis. However, developing photocatalysts that achieve nearly 100% carbon monoxide (CO) selectivity while maintaining a high production rate remains a great challenge. Herein, a U-L-Fe metal-organic framework (MOF)-based photocatalyst was successfully synthesized by a mixed-ligand strategy followed by light-induced deposition. As a result, U-L-Fe exhibits a high CO production rate of 9.50 mmol g −1 h −1 with a remarkable selectivity of nearly 100% under visible light, surpassing those of previously reported metal-organic framework MOF-based catalysts. In situ Fourier transform infrared (FTIR) spectroscopy identifies *COOH and *CO species as crucial intermediates in the photoreduction of CO 2 to CO. This work provides valuable insights for designing highly efficient MOF-based catalysts for CO 2 conversion and offers practical strategies for optimizing their activity. • U-L-Fe delivers 9.50 mmol g −1 h −1 CO with nearly 100% selectivity under visible-light irradiation • In situ FTIR spectroscopy identifies COOH* and CO* as key intermediates for CO 2 -to-CO conversion • Surpassing previously reported MOF-based photocatalysts