Metal nanoparticles supported chitosan coated carboxymethyl cellulose beads as a catalyst for the selective removal of 4-nitrophenol.

In the area of water pollution treatment, the coupling of biopolymers with metal/metal nanoparticles is getting a lot of interest these days. Herein, carboxymethyl cellulose (CMC) beads and chitosan (Cs) coated CMC beads were employed as a support for copper nanoparticles, (Cu/CMC) and (Cu/Cs@CMC), respectively. Following that, a reducing agent (NaBH4) was used to convert Cu/CMC and Cu/Cs@CMC beads to zero valent. The developed beads were employed for catalytic reductions of nitrophenol, dyes, and potassium hexacyanoferrate (III) in their mixed solution with NaBH4. Cu/Cs@CMC beads were more efficient compared to Cu/CMC beads toward selected pollutants. The reduction rate constants of 4-NP, MO, EY and K3[Fe(CN)6] by utilizing Cu/Cs@CMC were 3.8 × 10-1, 4.0 × 10-1, 1.4 × 10-1 and 4.48 × 10-1 min-1, respectively. Further, the catalytic activity of the Cu/Cs@CMC beads were optimized using 4-NP as a model compound for this study. Cu/Cs@CMC beads were able to use up to three cycles compared to Cu/CMC beads without losing catalytic activity in the reduction of 4-NP, according to the recyclability and reusability study of both beads. The chitosan coating beads Cu/Cs@CMC was simply prepared and have good catalytic activity, recyclable, and more efficient than Cu/CMC beads due to their high strength and stability.