Fe2O3-NiO embedded calcium alginate-carboxymethyl cellulose composite as an efficient nanocatalyst for 4-nitrophenol reduction

A novel nanocomposite beads of calcium alginate-carboxymethyl cellulose composite (CA-CMC) with Fe2O3-NiO was developed as efficient and excellent nanocatalyst for reduction of organic and inorganic pollutants. In this work, CA-CMC/Fe2O3-NiO beads were synthesized by simple crosslinking method using AlCl3 as crosslinker agent. In the presence of sodium borohydride (NaBH4) and CA-CMC/Fe2O3-NiO beads, nitrophenol isomers (4-NP, 2-NP and 2,6-DNP), organic dyes (methyl orange (MO) and eosin yellow (EY)), were reduced in 2 min, while potassium hexacyanoferrate K-3[Fe(CN)(6)] was reduced in only 30 s. The results showed that CA-CMC/Fe2O3-NiO beads were efficient toward all the selected pollutants with high rate constants for 4-NP, MO, EY and K-3[Fe(CN)(6)], which found to be 2.50, 2.23, 1.74 and 4.82 (x10(-)(2)) s(-1), respectively. For the optimization of the catalytic activity of CA-CMC/Fe2O3-NiO beads, 4-NP was chosen. Moreover, the CA-CMC/Fe2O3-NiO beads could be used upto four times without losing their catalytic activities. The performance of the designed method was also tested for 4-NP reduction in four types of real samples (seawater 88.5% in 8 min, wastewater 69% in 7 min, orange juice 90.2% in 4 min and full-fat milk 73% in 8 min). Thus, the developed material is promising for catalytic reduction of selected pollutants.