Immobilization of Nickel Oxide Nanoparticles on Cotton Fiber Under Gamma Radiation and Its Catalytic Activity

Nickel ions were reduced on the surface of cotton fibers under the effect of gamma radiation. The NiO nanoparticles grew as semispherical aggregates along the cotton fibers with average crystallite size of 32 nm as calculated from the x-ray diffraction results. The FTIR data showed the presence of a new IR peak at 613 cm^-1 (assigned to the NiO stretching vibration) confirming the successful loading of NiO nanoparticles into cotton matrix. The NiO nanoparticles were adhered to the surface of cotton fibers through the complexation with hydroxyl and carbonyl groups. The NiO@cotton nanocomposite showed high performance in the catalytic degradation of both 4-nitrophenol and bromophenol blue. The rate constant of the catalytic degradation of 4-nitrophenol was 8.24 × 10^-3 s^-1 at pH = 10. The resultant heterogeneous catalyst is green, cheap, separable/recyclable, and has considerable catalytic activity.