Polydopamine-Coated Polyurethane Foam as a Structured Support for the Development of an Easily Reusable Heterogeneous Photocatalyst Based on Eosin Y

An easy-to-handle eosin Y-based heterogeneous photocatalyst was prepared by post-functionalization of a polydopamine-coated open cell polyurethane foam (PDA@PUF) via the silanization adhesive layer with 3-(triethoxysilyl)propan-1-amine (APTES) and subsequent EDC-mediated coupling resulting amino-functionalized Y. The obtained macroscopic material, EY-APTES@PDA@PUF, showed good efficiency excellent reusability, in an easy-to-carry “dip-and-play” mode for at least six runs as aerobic oxidation 2-methyl-5-nitroisoquinolin-2-ium iodide to corresponding isoquinolone. Subsequent investigation catalytic EY-APTES@PDA@PUF sulfides sulfoxides, however, evidenced non-negligible Y leaching, leading progressive deactivation this case. Two alternative synthetic protocols preparation were next explored avoid leaching. In both cases cycling tests also highlighted foams sulfide-to-sulfoxide reactions.