Structural studies of bio-mediated NiO nanoparticles for photocatalytic and antibacterial activities

Nickel Oxide (NiO) nano-sized sample was bio-synthesized by a microwave-assisted route consuming citrus variety fruit juice. The prepared NiO sample was investigated by various spectroscopy techniques. The X-ray diffractogram revealed the formation of a cubic spinel with a well crystalline nature of NiO nanoparticles with a very fine crystallite size of 20 run. FTIR revealed Ni-O and smaller C-H and H-O-H characteristic functional groups, whereas the morphological characteristics determined by SEM and TEM disclosed a spherical shape of prepared nanoparticles. Elemental compositions present in NiO nanoparticles were found by EDAX as per the requirement. Emission peaks of luminescence were noticed at 350, 441, 485, and 531 nm. The spherical NiO nanoparticles showed 91% photodegradation efficiency for Evans blue under sunlight. Furthermore, the antibacterial performance of NiO sample was determined by agar well diffusion technique, which demonstrated significant cell inhibition in contradiction of both bacterial strains of gram-positive and gram-negative.