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.