UTILIZATION OF BIOWASTE (Allium cepa L PEEL EXTRACT) FOR THE SYNTHESIS OF MgO-NPs FOR THEIR ENERGY HARVESTING POTENTIALS

The synthesis of Magnesium oxide nanoparticles (MgO-NPs) with the use of Allium cepa L (onion) peel waste is a promising alternative to traditional chemical methods. The Allium cepa L peel extract was used as a substrate for the synthesis of MgO-NPs using bottom-up approach. The extract phytochemically screened, demonstrated the presence of saponins, alkaloids, flavonoids, phenolics, and other bioactive compounds, which enhance and act as a bio-reductants to MgO-NPs formation. The biosynthesized MgO-NPs were investigated for optical properties, functional moieties, crystallinity state, elemental constituents, morphology, particle size and their energy harvesting abilities using UV-Visible spectrophotometry, Fourier Transform Infrared Spectrophotometry (FTIR), Energy Dispersive Spectrometry (EDX), Transmission Electron Microscopy (TEM), Scanning electron microscopy (SEM) and Tauc’s plot respectively. UV-Visible spectrum revealed that MgO-NPs showed maximum absorption at wavelength of 241nm in the ultraviolet region. FTIR results showed prominent peaks at 3464cm-1, 3360cm-1 represents stretching vibration of O-H group. The peaks at 1592cm-1, 1171 cm-1 represents the stretching vibration of aromatic C=C bond. EDX results revealed the elemental composition in percentages of the elements in the nanoparticles, showing Mg (69.96%, 3.85 keV), O (26.67 %, 1.09 keV) and C (8.34 %, 1.26 keV). PXRD revealed a crystalline, cubid shaped with porous surface for SEM. The particle size (average) of the nanoparticles as characterized by TEM were found to be 63 nm. The band gap energy was calculated using Tauc’s plot to be 3.57 eV.