Carboxymethyl cellulose embedded silica membrane impregnated with ZVI NPs for the catalytic detoxification of methyl orange dye and its kinetic and optimization studies

Polymer composites, carboxymethyl cellulose (CMC) and silica-coated carboxymethyl cellulose (CMCSi) were used as supports for zero-valent iron nanoparticles (Fe⁰ NPs), yielding dip-catalysts represented as CMC@Fe⁰ and CMCSi@Fe⁰. The catalysts were created through the adsorption of Fe³⁺ ions on the polymer matrices, with the subsequent chemical reduction with NaBH₄ in aqueous solution. Using FTIR, XRD, and FESEM, structural and morphological topographies were characterized. The composite's catalytic efficiency was evaluated through the degradation of methyl orange (MO) dye. CMCSi@Fe⁰ and CMC@Fe⁰ achieved 89.4 % and 85.0 % degradation in 8 and 13 min. Kinetic modeling disclosed that CMCSi@Fe⁰ followed pseudo-first-order kinetics (R² = 0.921, k_app = 4.44 min⁻¹), where CMC@Fe⁰ best fitted a zero-order (R² = 0.917). The impact of reaction parameters, including temperature, NaBH₄ concentration, MO concentration, and pH, was thoroughly explored. At elevated temperature, acidic pH, and higher NaBH₄ dosage, optimal degradation occurred. These findings validate that CMC@Fe⁰ and CMCSi@Fe⁰ membranes not only act as effective catalysts for dye detoxification but also hold the potential for water filtration and functional group transformation applications.