Integrating S-scheme photocatalysis with tandem carbonylation: A green and scalable strategy for CO valorization.

The rapid increase in atmospheric CO levels due to industrialization underscores the urgent need for innovative carbon valorization strategies. Photocatalytic CO reduction presents a sustainable solution; however, conventional systems suffer from inefficient charge separation and limited product applicability. Herein, a green and scalable tandem strategy is developed by integrating S-scheme photocatalysis with palladium-catalyzed carbonylation. A rationally designed CeO/BiS heterojunction leverages its hierarchical structure, broad visible-light absorption, oxygen-vacancy-mediated charge dynamics, and the S-scheme charge transfer mechanism to achieve highly efficient photocatalytic CO-to-CO conversion (14.05 mmol g, 98% selectivity). The generated CO is directly utilized in a subsequent carbonylation reaction under mild conditions, yielding high-value amides with near-quantitative CO utilization. This integrated approach eliminates the risks of CO handling and enhances economic viability, providing a direct and effective route for converting CO into fine chemicals. By bridging photocatalysis with industrial catalysis, this work advances sustainable carbon recycling technologies and opens avenues for the development of efficient CO conversion systems.