Construction of magnetically recoverable palladium deposited polymer brush catalyst for reduction of organic pollutants

Water contamination by nitroaromatic compounds and synthetic dyes poses serious environmental and health hazards, requiring the development of efficient, recyclable, and eco-friendly catalytic systems. In this study, a magnetically recyclable Pd–PAAm@Fe₃O₄ nanocatalyst was synthesized via surface grafting and reduction techniques, ensuring uniform dispersion of Pd⁰ nanoparticles on polyacrylamide-modified Fe₃O₄ without toxic reducing agents. The catalyst exhibited excellent activity for reducing 2-NP, 4-NP, 2,4-dinitrophenol, 2-NA, 4-NA, and 2,4-dinitroaniline, following pseudo-first-order kinetics, with the highest kₐₚₚ value of 5.23 min⁻¹. It also showed rapid degradation of organic dyes, achieving complete decolorization of methyl orange in 45 s and methylene blue in 120 s. The catalyst retained over 99 % efficiency for 4-NP reduction over five cycles, with low Pd leaching (0.10–0.16 %) and stable structure confirmed by XRD, SEM, TEM, and XPS, highlighting its potential for sustainable environmental remediation.