Scholarlink

<p>Iron oxide nanoparticles (IO-NPs) featuring synergistic hematite (α-Fe<sub>2</sub>O<sub>3</sub>) and goethite (α-FeO(OH)) phases were successfully synthesized via an eco-friendly green method using <i>Pelargonium graveolens</i> leaf extract as a natural reducing and stabilizing agent, with ferric chloride hexahydrate as the precursor. By systematically varying precursor concentration (25–200 mM) and applying controlled thermal annealing, we precisely tuned the phase composition: higher precursor concentrations favored goethite formation, while lower precursor concentration and elevated annealing temperatures promoted hematite crystallization. This dual-phase system facilitates enhanced electron transfer and reactive oxygen species (ROS) generation through Fe<sup>2+</sup>/Fe<sup>3+</sup> redox cycling, underpinning the nanoparticles improved antibacterial efficacy. Comprehensive characterization was performed using field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRPD), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and optical band gap analysis. Crystallite sizes and lattice strains were estimated via multiple models, including Scherrer, Monshi–Scherrer, Williamson–Hall, and size–strain plot methods, elucidating relationships between phase composition and structural attributes. Morphological studies revealed elongated hematite and needle-like goethite structures, with phase-dependent vibrational features confirmed by spectroscopic analyses. Antibacterial activities were assessed against Gram-positive (<i>Staphylococcus aureus</i>, <i>Bacillus subtilis</i>) and Gram-negative (<i>Escherichia coli</i>, <i>Pseudomonas aeruginosa</i>) strains using well diffusion assays. Goethite-rich IO-NPs exhibited notable inhibition zones, achieving 25 ± 2&#xa0;mm against <i>S. aureus</i>, attributed to enhanced ROS-mediated bacterial inactivation. Commercial gentamicin served as a positive control, contextualizing the clinical relevance of the green-synthesized IO-NPs. This work demonstrates that green synthesis-driven phase control enhances antibacterial performance via synergistic iron oxide phases and redox mechanisms, highlighting the potential of eco-friendly IO-NPs for sustainable biomedical and environmental applications.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Eco-friendly synthesis of iron oxide nanoparticles (IO-NPs): grain size and strain estimation models, band gap calculations, and antibacterial properties

  • 期刊论文

  • 发表日期：

    2025年10月10日

查看全文
  • L. Boumaza,
  • S. Boudjadar,
  • O. Abdelaziz,
  • A. Mougari,
  • M. Zabat,
  • Y. Aouabdia

摘要

Iron oxide nanoparticles (IO-NPs) featuring synergistic hematite (α-Fe2O3) and goethite (α-FeO(OH)) phases were successfully synthesized via an eco-friendly green method using Pelargonium graveolens leaf extract as a natural reducing and stabilizing agent, with ferric chloride hexahydrate as the precursor. By systematically varying precursor concentration (25–200 mM) and applying controlled thermal annealing, we precisely tuned the phase composition: higher precursor concentrations favored goethite formation, while lower precursor concentration and elevated annealing temperatures promoted hematite crystallization. This dual-phase system facilitates enhanced electron transfer and reactive oxygen species (ROS) generation through Fe2+/Fe3+ redox cycling, underpinning the nanoparticles improved antibacterial efficacy. Comprehensive characterization was performed using field emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRPD), Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and optical band gap analysis. Crystallite sizes and lattice strains were estimated via multiple models, including Scherrer, Monshi–Scherrer, Williamson–Hall, and size–strain plot methods, elucidating relationships between phase composition and structural attributes. Morphological studies revealed elongated hematite and needle-like goethite structures, with phase-dependent vibrational features confirmed by spectroscopic analyses. Antibacterial activities were assessed against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) strains using well diffusion assays. Goethite-rich IO-NPs exhibited notable inhibition zones, achieving 25 ± 2 mm against S. aureus, attributed to enhanced ROS-mediated bacterial inactivation. Commercial gentamicin served as a positive control, contextualizing the clinical relevance of the green-synthesized IO-NPs. This work demonstrates that green synthesis-driven phase control enhances antibacterial performance via synergistic iron oxide phases and redox mechanisms, highlighting the potential of eco-friendly IO-NPs for sustainable biomedical and environmental applications.

Graphical Abstract