A TADF-based purely organic heterogeneous photocatalyst with hydrophobic domains for efficient oxidation of sulfide into sulfoxide in water

Abstract

Visible-light-promoted aerobic oxidation of sulfide into sulfoxide with water as the sole solvent is of great interest in green chemistry. Herein, two purely organic heterogeneous photocatalysts based on a TADF compound were prepared and used for this oxidation transformation. The difference in catalytic activity between the two photocatalysts was conveniently revealed and attributed to the way the photocatalysts were cross-linked. Higher catalytic activity was achieved by cross-linking methyl carbonate bonds and forming hydrophobic domains inside the photocatalyst. Inhibition and in situ ESR experiments provided mechanistic insight into the photocatalytic sulfoxidation reaction and confirmed that both ¹O₂ and O₂˙⁻ were involved in the catalytic process.