Scholarlink

<p>The current study presents undoped zinc oxide and dysprosium-doped ZnO nanopowders (NPs) over the concentration range of 1–5 at%, prepared by co-precipitation with the aim of examining their dielectric properties and photocatalytic performance in the degradation of methylene blue (MB) dye under sunlight exposure. X-ray diffraction characterization revealed the coexistence of a primary wurtzite structure and a cubic Dy<sub>2</sub>O<sub>3</sub> secondary phase in the Dy-doped ZnO nanopowders. The lattice parameters show a non-monotonic evolution and a significant improvement in crystallinity, where the average crystallite size increased from 20 nm for undoped ZnO to a range of 24 to 33 nm for Dy-doped samples. This structural enhancement is attributed to defect-assisted diffusion and the relaxation of internal lattice strains. Dielectric properties were investigated as a function of frequency (from 40 to 10<sup>7</sup> Hz) and temperature (in the range of 430 K to 540 K). The AC conductivity variations suggest that the non-overlapping small polaron tunneling (NSPT) model is the predominant conduction mechanism in our samples. Furthermore, a significant increase in electrical conductivity was recorded at 480 K, rising from 2.11 x 10<sup>−4</sup> to 13.03 x 10<sup>−3</sup> Ω<sup>−1</sup> m<sup>−1</sup> as the Dy doping concentration increased from 0 to 4%. Impedance and electric modulus analyses revealed localized charge carrier movement and non-Debye relaxation. Photocatalytic tests demonstrated that Dy doping improved the photocatalytic performance during MB degradation, with the 1% Dy-doped ZnO exhibiting the highest decolorization efficiency, achieving 98% within only 75 min of sunlight irradiation. These results suggest that lower Dy doping levels optimize the photocatalytic activity of ZnO NPs, making them promising for environmental protection applications such as wastewater treatment. In contrast, higher Dy doping concentrations improve their dielectric properties, indicating potential for energy storage technologies. This dual functionality highlights the versatility of Dy-doped ZnO nanomaterials for both environmental remediation and advanced energy applications.</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

Synergistic effects of dysprosium doping concentration on the electrical and photocatalytic performance of ZnO nanostructures

  • 期刊论文

  • 发表日期：

    2026年6月2日

查看全文
  • Safa Hamdi,
  • Hichem Smaoui

摘要

The current study presents undoped zinc oxide and dysprosium-doped ZnO nanopowders (NPs) over the concentration range of 1–5 at%, prepared by co-precipitation with the aim of examining their dielectric properties and photocatalytic performance in the degradation of methylene blue (MB) dye under sunlight exposure. X-ray diffraction characterization revealed the coexistence of a primary wurtzite structure and a cubic Dy2O3 secondary phase in the Dy-doped ZnO nanopowders. The lattice parameters show a non-monotonic evolution and a significant improvement in crystallinity, where the average crystallite size increased from 20 nm for undoped ZnO to a range of 24 to 33 nm for Dy-doped samples. This structural enhancement is attributed to defect-assisted diffusion and the relaxation of internal lattice strains. Dielectric properties were investigated as a function of frequency (from 40 to 107 Hz) and temperature (in the range of 430 K to 540 K). The AC conductivity variations suggest that the non-overlapping small polaron tunneling (NSPT) model is the predominant conduction mechanism in our samples. Furthermore, a significant increase in electrical conductivity was recorded at 480 K, rising from 2.11 x 10−4 to 13.03 x 10−3 Ω−1 m−1 as the Dy doping concentration increased from 0 to 4%. Impedance and electric modulus analyses revealed localized charge carrier movement and non-Debye relaxation. Photocatalytic tests demonstrated that Dy doping improved the photocatalytic performance during MB degradation, with the 1% Dy-doped ZnO exhibiting the highest decolorization efficiency, achieving 98% within only 75 min of sunlight irradiation. These results suggest that lower Dy doping levels optimize the photocatalytic activity of ZnO NPs, making them promising for environmental protection applications such as wastewater treatment. In contrast, higher Dy doping concentrations improve their dielectric properties, indicating potential for energy storage technologies. This dual functionality highlights the versatility of Dy-doped ZnO nanomaterials for both environmental remediation and advanced energy applications.