Green Zinc Oxide (ZnO) Nanoparticle Synthesis Using Mangrove Leaf Extract from Avicenna marina: Properties and Application for the Removal of Toxic Metal Ions (Cd2+ and Pb2+)

Abstract

This work used a variety of experimental studies to explore the elimination of cadmium and lead ions from aqueous solutions using a novel method for the biosynthesis of nanoparticles of zinc oxide sorbents (ZnO-NPs) from mangrove leaf extract. The influences of important factors affecting the adsorption technique were determined, including the pH value, contact duration, the initial concentration of metal ions, nano-adsorbent dose, different temperatures, and interfering ions. To confirm the formation of synthesized ZnO NPs and validate the properties of green-synthesized sorbents, a variety of analytical methods were used, including UV–vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The results showed that the average diameter of the ZnO-NPs was approximately 29.1 nm (spherical at the nano-size regime). The adsorption reaction rate was examined by comparing pseudo-second order against pseudo-first order templates. From the observed records, the adsorption reaction of Cd2+ and Pb2+ on the ZnO-NPs fitted well with the pseudo-second order template. Freundlich, Langmuir, Dubinin–Radushkevich, and Tempkin equilibrium isotherm models were used to evaluate the sorption of Cd2+ and Pb2+ onto the sorbent material. Based on the parameters extracted from each model, as well as the model-fitting values, the preferential isotherms for Pb2+ and Cd2+ ion adsorption on ZnO-NPs were the Dubinin–Radushkevich and Langmuir models, respectively. ZnO-NPs have the potential to be used as an effective and promising adsorbent material for eliminating metal ions from water solutions.

Biosorption of Escherichia coli Using ZnO-Trimethyl Chitosan Nanocomposite Hydrogel Formed by the Green Synthesis Route

“…The primary adsorption mechanism was determined further using the Langmuir, Freundlich, Harkin-Jura, Halsey, Redlich-Peterson, and Jovanovic isotherm models. Comparing the obtained goodness-of-fit values for the Langmuir and Freundlich models, the experimental data as presented in Figure 5a,b show the adsorption of E. coli onto the NC surface well described by the Langmuir adsorption isotherm (R 2 = 0.9901) compared to the Freundlich model (R 2 = 0.9399), suggesting majorly the existence of a homogeneous adsorption processes [54]. Thus, the adsorption results generated from this study suggested that the adsorption process predominantly occurs homogeneously at the surface sites of TM@ZnO/TMC NC hydrogel and that the adsorption of E. coli may be assumed to be of monolayer coverage [42].…”

Improving the Production of Secondary Metabolites via the Application of Biogenic Zinc Oxide Nanoparticles in the Calli of Delonix elata: A Potential Medicinal Plant

“…The green synthesis of ZnONPs was first confirmed via UV–visible spectroscopic analysis, which showed an absorption peak at 370 nm ( Figure 1 a). The absorption peak at this range could be explained by the intrinsic band-gap absorption of ZnO, possibly from the electron exchange from the valence band to the conduction band [ 69 , 71 ]. The ZnONP colloidal solution stability was assessed using the zeta potential based on the charge of fabricated nanoparticles [ 72 ].…”

Exploring the potential of a Ephedra alata leaf extract: Phytochemical analysis, antioxidant activity, antibacterial properties, and green synthesis of ZnO nanoparticles for photocatalytic degradation of methylene blue

“…Neem ( Azadirachta indica ) and tulsi ( Ocimum tenuiflorum ) extracts yielded oval-shaped ZnO NPs with sizes of 100 nm and 122 nm, respectively ( Ajayan and Hebsur, 2020 ). A mangrove leaf extract was used to synthesize spherical ZnO NPs with a size of ∼30 nm ( Al-Mur, 2023 ). Using Costus pictus D. extract, ZnO NPs with tailored size and morphology were fabricated (hexagonal and rod shapes with a reported size of 29 nm) ( Suresh et al, 2018 ).…”