Ni /Fe3O4@Nanocellulose and Ni/Nanocellulose Green Nanocomposites: Inorganic- Organic Hybrid Catalysts for the Reduction of Organic Pollutants

In this work, Ni NPs have been in-situ synthesized using hydrazine as a reducing agent and immobilized on nanofibrillated cellulose (Ni/NFC) and magnetic nanofibrillated cellulose (Ni/Fe3O4@NFC) as green supports. The structure and morphology of the Ni/Fe3O4@NFC nanocomposite clarified high purity single-phase spherical-shaped Ni nanoparticles of about 30 nm distributed on the surface of nanocellulose as compared to the larger size of star shape particles in Ni/NFC. The catalytic activity of both nanocomposites was investigated for the reduction of 4-nitrophenol (4-NP), Methyl Orange (MO), and Methylene Blue (MB). The results demonstrated high catalytic efficiency toward the removal of water pollutants in a short reaction time. The reduction rate constants (k) of freeze-dried Ni/Fe3O4@NFC catalyst were 30 ×10-³ s-¹, 17.3×10-³ s-¹, and 6.9 ×10-³ s-¹, for 4-NP, MO, and MB respectively, which were higher than those of synthesized Ni/NFC and other reported Ni-based catalysts. Moreover, the catalyst could be easily magnetically recoverable and reusable in other cycles.