Anchoring Zero-Valent Cu and Ni Nanoparticles on Carboxymethyl Cellulose-Polystyrene–Block Polyisoprene–Block Polystyrene Composite Films for Nitrophenol Reduction and Dyes Degradation

In the present study, carboxymethyl cellulose (CMC) is dispersed in polystyrene block polyisoprene block polystyrene polymer (PSIS) to make a composite film (CMC-PSIS) through a simple casting technique followed by adsorption of Cu and Ni ions from their respective salt solution. After that, it was converted to their respective Cu⁰ and Ni⁰ nanoparticles (NPs) in aqueous medium in the presence of NaBH₄ on the surface of CMC-PSIS and was named as CMC-PSIS/Cu and CMC-PSIS/Ni respectively. The prepared catalysts were extensively characterized through different techniques. The morphology of catalysts was studied using FESEM while the EDS and XPS techniques were used for determining the elemental composition and binding energy of both the catalyst. Similarly, FTIR and XRD were used for functional groups and crystalline nature determination of the catalysts. Both catalysts were applied as dip-catalyst in the presence of NaBH₄ as reducing agent against the reduction/degradation of four model pollutants such as 4-nitrophenol, methylene blue, rhodamine B (RB), and methyl orange dyes (MO). The highest rate constant value (3.75 × 10^–1 min⁻¹) was observed for the MO degradation using CMC-PSIS/Cu. Similarly, the shortest reaction time i.e., (3 min) was observed for MO degradation by using Cu NPs. The RB degraded up to maximum extent (97.7%) among all dyes by using CMC-PSIS/Ni. The experimental data was well-fitted in the zeroth order of kinetics.