Biosynthesis of cobalt oxide (Co3O4) nanoparticles using plant extract of Camellia sinensis (L.) Kuntze and Apium graveolens L. as the antibacterial application

In this work, we prepared cobalt oxide nanoparticles using Celery stalks and green tea leaves extract. The synthesized cobalt-oxide NPs were characterized using X-Ray diffraction. This showed the highest peak and top control (222) at (38.18 degree) with regard to Camellia sinensis extract and (220) at (30.14 degree) for Apium graveolens extract, Field Emission scanning electron microscopy (EF_SEM) at the range of 21-72 nm, revealed the highly uniform shape of particles, while UV-Visible spectroscopy techniques recorded the highest value of the absorptive at 230 nm and the energy band gap to be 3.55 eV for Camellia sinensis and 225 nm and energy band gap 3.85 eV at Apium graveolens, respectively. Our results indicate that the best achievable result in inhibiting bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa comes by way of using Camellia sinensis extract (27-29 mm).