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1.
Molecules ; 29(2)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38257268

RESUMO

This study successfully synthesized zinc oxide nanorod needles (ZnO-NRNs) using an environmentally friendly method employing Cymbopogon Proximus extract. The resulting ZnO-NRNs exhibited exceptional physicochemical and structural properties, confirmed through various characterization techniques, including UV-Vis spectrophotometry, dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). The analysis revealed a hexagonal wurtzite structure with high crystallinity, a 3.6 eV band gap, and a notably blue-shifted absorption band. ZnO-NRNs showed impressive photocatalytic activity, degrading Rhodamine B dye by 97% under UV and visible sunlight, highlighting their photostability and reusability. This green synthesis process offers cost effectiveness and environmental sustainability for practical applications.

2.
Heliyon ; 10(12): e32714, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-39022102

RESUMO

This research describes the methodology for synthesizing zinc oxide nanoparticles (ZnO-NPs). It demonstrates a unique, cost-effective, and non-toxic chemical technique for producing ZnO-NPs using the precipitation method with NaOH as reducing and capping agents. The formed nanoparticles have been characterized and analyzed using numerous techniques such as; Fluorescence emission spectroscopy (FL), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray Spectroscopy (EDX), ultraviolet-visible optical absorption (UV-Vis), Fourier transform infrared spectroscopy (FTIR), and Thermal gravimetric analysis (TGA). Also, the analytical technique X-ray diffraction studies has been used which showed that the ZnO-NPs had a Wurtzite hexagonal crystal structure with an average crystallite size of 34.27 nm. The form and the size of the synthesized ZnO-NPs have been seen in SEM and TEM photographs. Using J-image, particle size has been obtained at 13.33 nm, and the grain boundaries were all approximately spherical. Peaks in the FT-IR spectrum of the NPs indicate the presence of carboxylate (COO) and hydroxyl (O-H) functional groups. According to these findings, Zn interstitial defects are responsible for the 380 nm emission peak. Since EDX could not identify any impurities below the detection threshold, we may be sure that Zn and O are the principal components of the synthesized sample. ZnO-NPs cause an absorption band at 350.34 nm in the UV-Vis spectrum and a band gap of 3.24 eV. The catalytic activity of the synthesized ZnO nanoparticles (NPs) was evaluated by investigating their effectiveness in degrading crystal violet (CV) and methylene blue (MB) dyes, along with assessing the degradation rates. The results demonstrated a high degradation efficiency, with ZnO NPs achieving approximately 96.72 % degradation for CV and 97.169 % for MB dyes, underscoring their remarkable efficacy in the degradation process. As for antimicrobial activity assessment, the results revealed that the ZnO-NPs had negligible impact on Gram-negative bacteria, whereas they exhibited a discernible effect on Gram-positive bacteria. Additionally, it showed anti-cancer potential against colon (SW480), breast (MDA-231), and cervix (HELA) lines cells as seen by (MTT) assay. Hence, due to its simplified processes and cheaper chemicals, our synthesis technique may use in industrial settings for various applications.

3.
ACS Omega ; 7(3): 2786-2797, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35097275

RESUMO

In the present work, the aim is to synthesize reduced graphene oxide (rGO) and zinc:reduced graphene oxide composite catalysts (ZnO:rGO) for esterification of acetic acid with n-heptanol. The physical and chemical characteristics of the rGO and rGO-metal oxide composite catalysts such as textural surface characteristics, surface morphology, thermal stability, functional groups, and elemental analysis were studied. The surface areas of rGO, ZnO(0.5 M), and ZnO(1 M) were recorded, respectively, at 31.72, 27.65, and 36.19 m2 g-1. Furthermore, esterification reaction parameters such as the reaction time, catalyst dosage, and reaction temperature for acetic acid were optimized to check the feasibility of rGO-metal oxide composites for a better conversion percentage of acetic acid. The optimized catalyst was selected for further optimization, and the optimum reaction parameters found were 0.1 wt % of catalyst, 160 min reaction duration, and 100 °C reaction temperature with a maximal yield of 100%. At 110 °C, the reaction conducted in the presence of 0.1 g of catalyst displayed more yield than the uncatalyzed reaction.

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