Thermally assisted photocatalytic industrial flue gas CO2 conversion: 100% selective CO production via synergistic adsorption–conversion in NH2–MXene–MOF hierarchical interfaces

Abstract

Thermally assisted photocatalytic CO₂ conversion into high value-added chemicals represents an effective strategy for carbon emission reduction and circular carbon economy. This study constructed an integrated gas–solid interface thermally assisted photocatalytic system using NH₂-MXene/TiO₂/NH₂-MIL-125 (Ti-NMT), achieving in situ CO₂ capture from industrial flue gases and its efficient conversion to carbon monoxide (CO) with a production efficiency of 332.43 μmol g⁻¹ h⁻¹, along with 100% selectivity, and 94% activity retention over 5 cycles. The exceptional catalytic performance is attributed to MXene's metallic conductivity for rapid interfacial electron transfer, amine-induced Lewis acid–base interactions that enhance CO₂ adsorption via dual-binding sites, and charge separation driven by synergistic S-scheme heterojunction and Schottky barrier effects. In addition, MXene's localized surface plasmon resonance (LSPR) effect boosts hot carrier density and reduces the activation energy of the catalytic reaction. This work resolved critical bottlenecks through heterointerface engineering and functional group optimization, providing both a viable pathway and experimental validation for industrial flue gas CO₂ capture and resource recovery.