Synthesis of flower-like covalent organic frameworks for photocatalytic selective oxidation of sulfide

Abstract

BackgroundCovalent organic frameworks (COFs)-based photocatalysts have garnered significant attention for their potential in highly efficient and selective sulfide oxidation. However, the current synthesis methods of COF-based catalysts involve complex multi-step procedures, and better methods need to be upgraded for synthesis. MethodsIn this study, a flower-like COF-based photocatalyst (f-COFs) was synthesized by one-pot method at room temperature using zinc chloride (ZnCl2) as catalyst. The photocatalytic performance of f-COFs was investigated using methyl phenyl sulfide as substrate. Significant FindingsZinc ions remain on the f-COFs synthesized by this method. EDX analysis and XPS techniques were used to confirm the presence of zinc ions. The presence of zinc ions controls the self-assembly of COFs to form unique flower-like microstructure. Its flower-like microstructure provides a strong light absorption capacity. At the same time, the recombination of charge is inhibited, thus promoting the energy and electron transfer during the photocatalytic reaction. These properties allow reactive oxygen species to be prevalent in the reaction process of f-COFs as a photocatalyst, driving the conversion of methyl phenyl sulfide to sulfoxide within 5 h with excellent performance of 95 % conversion and 99 % selectivity.