Sein–EY marvels: effortless elegance in crafting flexible film photocatalysts for formic acid production from CO2 and cyclization of thioamides in the air's embrace.

Carbon dioxide reduction together with aerobic oxidative cyclization using eosin Y-based light-harvesting photocatalysts remains a key challenge. In this study, we present the first-ever synthesis of unique in situ Se-infused eosin Y (Sein–EY) flexible photocatalysts through a simple one-pot method. The as-synthesized Sein–EY flexible film photocatalyst exhibits outstanding performance for the production of formic acid (204 μM in 2 h) and aerobic oxidative cyclization of thioamides via the formation of C–N/C–S bonds with outstanding yields (98.6%) when exposed to solar light. The presence of infused Se significantly extends the solar light absorption capacity of the Sein–EY photocatalyst, reaching up to 580 nm. This study opens up a new pathway for the rational design and synthesis of potentially effective Se-infused-EY photocatalysts through a simple and scalable method, enabling both solar chemical production and efficient one-pot three-component reactions. [ABSTRACT FROM AUTHOR]