Photothermally Boosted CO 2 Conversion by Silver Nanoparticles Anchored on a Bipyridinium Radical‐Functionalized Covalent Triazine Framework

Developing sustainable and energy‐efficient catalytic systems for CO 2 conversion is pivotal for advancing carbon cycle management, yet remains highly challenging. Here, we report a novel near‐infrared (NIR) photothermal catalytic platform by depositing silver nanoparticles onto a bipyridinium radical‐functionalized covalent triazine framework (CTF) for the carboxylative cyclization of propargylic amines with CO 2 without external heating. It is found that, under 808 nm laser irradiation, the catalyst delivers a 6.9‐fold enhancement in photothermal catalytic activity relative to its bipyridinium‐free analogue. Due to the exceptional penetration depth of near‐infrared light, this photothermal catalytic system achieves a record turnover frequency of 2952.1 h −1 even in the presence of translucent barriers. The stabilizing effect of extended π‐conjugation within the CTF matrix on bipyridinium radicals maintains the high photothermal catalytic activity over 10 consecutive cycles. Furthermore, this photothermal catalytic system demonstrates practical scalability, allowing for gram‐scale (∼10 g) one‐pot synthesis of an oxazolidinone product under natural sunlight. This work not only provides a novel approach for promoting value‐added CO 2 conversion under mild conditions, but also demonstrates the transformative potential of bipyridinium radicals in designing high‐performance NIR photothermal catalytic systems.