Carboxymethyl cellulose nanocomposite beads as super-efficient catalyst for the reduction of organic and inorganic pollutants

Carboxymethyl cellulose/copper oxide-nickel oxide (CMC/CuO-NiO) nanocomposite beads were prepared by facile, simple and environmentally friendlymethod. Initially, CuO-NiOwas prepared and applied for the catalytic reduction of 4-nitrophenol (4-NP). The results showed that CuO-NiO demonstrate high catalytic activity toward the reduction of 4-NP to 4-aminophenol (4-AP) with a rate constant of 2.97 x 10(-2) s(-1). Further, CuO-NiO were well-dispersed in the polymeric matrix of carboxymethyl cellulose to prepare CMC/CuO-NiO beads. CMC/CuO-NiO nanocomposite beads were also applied to catalyze the reduction of potassium ferrocyanide (K3Fe (CN)(6)), 4-NP, Congo red (CR) and Eosin yellow(EY) in the presence of sodiumborohydride. Experimental data indicated that CMC/CuO-NiO nanocomposite has higher catalytic activity and high rate constant compared to CuO-NiO. The rate constant found to be 6.88 x 10(-2), 6.27 x 10(-2), 1.89 x 10(-2) and 2.43 x 10(-2) for K3Fe(CN)(6), 4-NP, CR and EY, respectively, using 5 mg CMC/CuO-NiO beads. FE-SEM, EDX, FTER, XRD and XPS were used to characterize the nanocomposites. CMC/CuO-NiO beads catalytically reduced up to 95-99% of K3Fe(CN)(6), 4-NP, CR and EY within 40, 60, 120 and 120 s. CMC/CuO-NiO beadswere found more selective for the reduction of 4-NP. The catalytic reduction performance of CMC/CuO-NiO beadswas optimized by studying the influence of different parameters on the catalytic reduction of 4-NP. Hence, the effective and super catalytic performance toward the reduction of different organic and inorganic pollutants makes CMC/CuO-NiO beads a smart material and suitable for numerous scientific and industrial applications and may be used as an alternative to high-cost commercial catalysts. (C) 2020 Elsevier B.V. All rights reserved.