Easily Applicable Heterogeneous Catalyst from Sustainable Resources: Anchoring of Pd Nanoparticles onto Chemically Poly(2-amino thiophenol)-Modified Wool Fabrics

For preparing the Pd nanoparticle (PdNP)-decorated heterogeneous catalyst material, wool fabric was utilized as a practical platform after enriching its chemical functionality with two straightforward chemical processes. First, wool keratin was transformed to a reduced structure (WSH) with NaHS by extracting −SH groups and then reconstructed to the S–S linkages by the covalent attachment of 2-amino thiophenol (2-ATP). The graft copolymerization of 2-ATP onto this 2-ATP/WSH surface was ensured to prepare a P2ATP-g-WSH copolymer fabric. As the second process, the polymerization of 2-ATP was also performed on the WSH fabrics to prepare a P2ATP/WSH composite. The PdNP anchoring was subsequently ensured onto these copolymer and composite samples through the in situ reduction of Pd2+ to the PdNPs. The conditions yielding the highest PdNP content were investigated in detail, and the PdNP formation abilities of both fabrics prepared by different routes were compared. It was observed that the contribution of PdNPs through the P2ATP/WSH composite route was relatively high compared to that of the copolymer route. The structural and morphological alterations in the wool nature, the existence, the oxidation state, and the relative abundance (%) of PdNPs with respect to the Pd2+ ions were evidenced by many techniques in detail. After examining the performance of the PdNP composites in the catalytic reduction of two nitroarenes to the aminoarenes, the Pd/P2ATP/WSH demonstrated satisfactorily high performance in terms of reduction yield (%), reduction rate constant (min–1), and reusability, compared to that of Pd/P2ATP-g-WSH.