Facile and Green Synthesis of Zinc Oxide Nanoparticles Using Plant Extracts and Its In vitro Photocatalytic Activity

다국어 초록 (Multilingual Abstract)

A green biosynthetic approach of zinc oxide nanoparticles using coprecipitation method with dried fruit extract of Amomum longiligulare (A. longiligulare) is reported in this study, as it is plant- derived reducing agent. For configuration of Al-ZnO NPs (Amomum longiligulare - Zinc Oxide Nano Particles), the absorption of wavelength of nanoparticles was observed by UV–vis spectra at 354 nm. XRD (X-ray diffraction) micrograph and FETEM (Field-Emission Transmission Electron Microscopy) determined the morphological structure of green synthesized Al-ZnO. The chemical functional group, elemental mapping, and crystallization of nanoparticles were characterized by FTIR (Fourier Transform Infrared Spectroscopy), and EDX (Energy dispersive X-ray spectroscopy). The photocatalytic activity of Al- ZnO NPs was confirmed by photodegradation of methylene blue and malachite green dyes under 356 nm of UV light irradiation in aqueous solution. The degradation of MB with Al-ZnO NPs was completed with approximately 66 % in 60 min, whereas MG degradation was measured around 38.1% by 60 min by Al-ZnO NPs, respectively. The kinetic reaction rate as stated by first-order reaction of photocatalytic degradation of MB (Methylene Blue) and MG (Malachite Green) with Al-ZnO NPs were found to be 0.014 min−1 and 0.008 min−1 respectively. Therefore, phytochemicals of A. longiligulare extract have capability to act as a reducing agent in biosynthesis of zinc nanoparticles and is suitable to produce cost-efficient and eco-friendly photocatalyst.
In addition, we have also studied the photocatalytic activity of Stevia rebaudiana leaves, which is a well-known medicinal plant for its non-caloric bio-sweetener. To enhance its value addition, employed first time for synthesis and stabilization of ZnO nanoparticles. The characterization using UV-Spec, FE-TEM, XRD, DLS revealed that SR-ZnO (ZnO particles obtained from S. rebaudiana) were flower-shape, 500–1,000nm sizes, hydrodynamic diameter Z-average of polydisperse SR-ZnO was 582.35±52.40nm with a PDI of 0.33±0.002. Furthermore, 76% degradation of methylene blue dye within 30min exposure to SR-ZnO and plant extract under UV light indicates that it could be utilized as an efficient photocatalyst for waste- water treatment.
Finally, we have also further synthesized Zinc Oxide Nanoparticles from Hippophae rhamnoides leaves extract via co precipitation method. Synthesized nanoparticles from leaves extract having ability to generate electron–hole (ē–h+) between the band gap of ZnO due to works as a photo catalyst in de- gradation of (Eosin Y, Malachite Green) textile dye. The photo catalysts were characterized with the UV–vis spectrometer, Field emission transmission electron microscopy (FE-TEM), Fourier transform infrared (FTIR), X-ray powder diffraction (XRD), Dynamic light scattering (DLS) analysis. The UV analysis confirmed the formation of ZnO nanoparticles at 374 nm. The FE-TEM images indicates that it is having flower like shape. The XRD data confirmed the size, and it is about 20.17 nm. The photocatalytic activity of the Synthesized NPs was evaluated using the Eosin Y and Malachite Green dye under UV irradiation. Our study found that it has ability to degrade dye about 95% and 89% respectively. So, Hippophae rhamnoides Leaves Zinc oxide nanoparticles (Hr- L-ZnO –NPs) can be a better photo catalyst for the treatment of polluted water through textile industry.
In this study, the photocatalytic activity and dye degradation of biosynthesized zinc oxide nanoparticle from three different plants such as Amomum longiligulare, Stevia rebaudiana and Hippophae rhamnoides has been studied and reported.