Sequential Deposition of Polyaminothiophenols and Gold Nanoparticle on Wool Fabrics: Fabric Composites as Efficient Catalysts in the Reduction of Nitroarenes

Abstract

AbstractMerino wool, a highly abundant natural fabric, was successfully transformed into a valuable substrate for preparing easily recoverable catalyst materials by depositing gold nanoparticles (AuNPs) through a series of modification steps. The functionality of wool was enhanced by cleaving‐SH groups using NaHS chemical reduction. Subsequently, the reduced wool keratin (WSH) was covalently attached to 3‐amino thiophenol (3‐ATP) or 4‐amino thiophenol (4‐ATP) monomers via S−S linkages. The surface was further modified by grafting P3ATP or P4ATP through oxidative polymerization of 3‐ATP or 4‐ATP using ammonium persulfate as an oxidant. Finally, AuNPs were deposited onto the P3ATP or P4ATP‐grafted wool (P3ATP‐g‐WSH or P4ATP‐g‐WSH) by immersing the samples in an aqueous HAuCl4 solution. Additionally, P3ATP or P4ATP‐coated composites (P3ATP/WSH or P4ATP/WSH) were prepared to assess the AuNP formation ability of the grafting. The structural and morphological changes occurred in the wool, and the presence of AuNPs was revealed by ATR‐FTIR, XPS, SEM, and contact angle. The catalytic performance of the AuNP‐containing composites in reducing various nitroarenes to aminoarenes using an excess of electron‐donor (NaBH4) was monitored by UV‐vis spectroscopy. The developed composites demonstrated high efficiency, reusability, and rapid catalytic activity, achieving the highest apparent rate constant of 3.79 min−1, even within 1 min.