Flower shaped ZnO - NPs; phytofabrication, photocatalytic, fluorescence quenching, and photoluminescence activities

Abstract

Phytofabrication of Zinc Oxide nanoparticles (ZnO-NPs) through Nephelium lappaceum L. and Garcinia mangostana L. plants' wastes were achieved as an environmentally friendly method of synthesizing nanoparticles. Biogenic ZnO-NPs were characterized by Ultra Violet Visible (UV-vis) spectrophotometry, Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Energy Dispersive Energy (EDX ), and Fourier Transform Infrared spectroscopy (FTIR). UV- Visible absorption of ZnO-NPs indicated a characteristic absorption band at 362-368 nm region. The synthesized nanoparticles were flower in shape, as shown by the SEM images, and they were further elucidated by the TEM images. ZnO-NP synthesized via Rambutan Peel Extract (RPE), Rambutan Seed Extract (RSE), Mangosteen Peel Extract (MPE) and Mangosteen Seed Extract (MSE) showed the average particle size of 29 nm-184 nm, 86 nm-260 nm, 92 nm-247 nm, and 233 nm-334 nm respectively. FTIR spectra demonstrated peaks at 3269-3500 cm-1, 2308-2361 cm-1, 2103-2110 cm-1 and 1630-1640 cm-1, 586-632 cm-1 for the plant extracts, whereas an additional peak appeared within the range of 458-499 cm-1 in ZnO-NPs spectra. The photocatalytic activity of the synthesized ZnO-NPs was measured by the degradation of Methylene Blue under sunlight. The highest degradation of Methylene Blue dye was detected in ZnO - NPs synthesized using the seed extract of Nephelium lappaceum L., where a Half-life of 78 min and 97% degradation efficiency at 150 min time frame was observed. The ZnO-NPs were identified to possess fluorescence quenching ability of Rhodamine B. The highest quenching ability was recorded in ZnO-NPs synthesized via Garcinia mangostana L. seed. The Photoluminescence study showed that the intensity of spectral lines of biogenic ZnO-NPs were higher compared with the chemically synthesized ZnO-NPs.