Nickel oxide and carboxymethyl cellulose composite beads as catalyst for the pollutant degradation

In this work, nickel oxide nanoparticles were synthesized by precipitation method from nickel nitrate solution with basic pH, followed by calcination at 550 °C. The ex-situ made nickel oxide nanoparticles were mixed with carboxymethyl cellulose biopolymer in 1:2 proportions for nanocomposite preparation in aqueous media. The mixed nanoparticles and polymer aqueous solution were extruded drop-wise from the sterile syringe into a gently agitating 0.02 M solution of AlCl 3 ·3H 2 O. As a result of this process, the nanocomposite beads were synthesized with a size of ~ 1.5–2 mm. These nanocomposite beads were then characterized by UV–visible, Fourier-transform infra-red spectroscopy, X-ray diffraction, and scanning electron microscopy. To monitor catalytic activity of synthesized nanocomposite, it was applied for the reduction of methylene blue dye. The nanocomposite beads showed excellent activity for detoxification of methylene blue dye. Rate of reaction for methylene blue reduction was calculated using data obtained from UV–visible spectrophotometry which was 0.1482 min −1 according to the pseudo first-order kinetics. The recyclability of NiO-CMC up to five consecutive cycles revealed its stability in aqueous medium. This work showed that nanocomposite beads have excellent catalytic efficacy against remediation of toxic pollutants in wastewater.