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.