Preparation of magnetic polymer brush/metal nanoparticle hybrid materials for the catalytic degradation of certain organic dyes

In this thesis study, a magnetically recoverable Pd-PAAm@Fe₃O₄ nanocatalyst was successfully synthesized by surface grafting and reduction methods. Polyacrylamide (PAAm) chains were strongly attached to the Fe₃O₄ surface, and Pd⁰ nanoparticles were homogeneously dispersed without using toxic reducing agents. This developed nanocatalyst showed high catalytic performance in the reduction of various nitro aromatic compounds such as 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), 2,4-dinitrophenol, 2-nitroaniline (2-NA), 4-nitroaniline (4-NA), and 2,4-dinitroaniline1. The reactions proceeded in accordance with pseudo-first-order kinetics. Furthermore, it was also effective in the degradation of dyes such as methyl orange, methylene blue, and methyl red; it degraded methyl orange 100% in just 45 seconds. VSM analysis revealed superparamagnetic properties, while XRD, SEM, and TEM characterizations confirmed the morphological and crystal stability of the structure. The presence of Pd⁰ species was confirmed by XPS analysis. The catalyst maintained over 99% effectiveness during five consecutive cycles during 4-NP reduction and showed a low level of Pd leaching (0.10–0.16%). The obtained results indicate that this nanocatalyst is a promising, reusable material for environmental remediation applications.