In the present work aluminium oxide nanoparticles are synthesized using leaf extract of Ocimum sanctum. The synthesized sample was characterized by XRD, HR – TEM, UV – Vis, FTIR and PL. It is found that aluminium oxide nanoparticles synthesized by leaf extract are stable and show good optical properties. This method of synthesis is less toxic and cost of synthesis is low as compared to other chemical and physical methods. By XRD pattern phase of synthesized aluminium oxide nanoparticles is confirmed and the average particle size is found to be 19.43 nm. By HR - TEM analysis, the particle size of synthesized nanoparticles ranges from 18 nm to 25 nm.  By UV – visible spectroscopy the energy band gap is found to be 2.55 eV. By FTIR analysis presence of Al–O band and biofunctional group is confirmed. Photoluminescence spectroscopy confirmed the energy band gap of as synthesized alumina nanoparticles is 2.19 eV. Hence, from the present study, it is concluded that aluminium oxide nanoparticles synthesized by plant leaf extract are good semiconductors.

Keywords: Aluminium Oxide; Green Synthesis; Optical Properties;