Scholarlink

<p>ZnO and Mg-doped ZnO nanopowders were synthesized via a simple sol–gel auto-combustion method to investigate their structural, optical, gas sensing, and photocatalytic properties. XRD and FTIR analyses confirmed the retention of the hexagonal wurtzite phase, with Mg doping slightly reducing the ‘<i>c</i>’ lattice parameter from 5.19 to 5.18&#xa0;Å. Photoluminescence (PL) studies revealed an increase in bandgap from 3.2&#xa0;eV (pure ZnO) to 3.4&#xa0;eV (10% Mg-doped ZnO), indicating lattice distortion and band structure modification. High-resolution TEM images showed an increase in <i>d</i>-spacing with Mg content, while XPS analysis revealed hydroxide species and altered chemical states, confirming successful Mg incorporation and modified surface chemistry. An enhanced NBE–defect emission ratio (<i>I</i><sub>NBE</sub>/<i>I</i><sub>defect</sub>) from PL spectra demonstrated improved radiative recombination and suppressed non-radiative losses, enabling superior light-harvesting for gas sensing and photocatalysis. Gas sensing measurements showed significant improvement in NO₂ detection at 200&#xa0;°C, with the response increasing from 72% for ZnO to 81% for Zn₀.₉₅Mg₀.₀₅O at 5&#xa0;ppm NO₂. The Mg-doped sample also exhibited faster response (27&#xa0;s), recovery (32&#xa0;s), and superior selectivity. Photocatalytic tests using methylene blue (MB) dye under xenon light revealed enhanced degradation efficiencies of 84%, 87%, and 88% for Zn<sub>1−<i>x</i></sub>Mg<sub><i>x</i></sub>O with <i>x</i> = 0, 0.05, and 0.10, respectively, with the highest rate constant (0.01781&#xa0;min<sup>−1</sup>) observed for 10% Mg doping. Improved performance is attributed to increased oxygen vacancies and enhanced charge separation. These results position Mg-doped ZnO as a promising multifunctional material for environmental remediation and gas sensing.</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

Defect and band gap engineering in Mg-doped ZnO for gas sensing and photocatalytic applications

  • 期刊论文

  • 发表日期：

    2025年7月19日

查看全文
  • A. R. Abhijith,
  • Tim Tim Mashangva,
  • Himani Sharma,
  • Amar Srivastava,
  • Reji Thomas

摘要

ZnO and Mg-doped ZnO nanopowders were synthesized via a simple sol–gel auto-combustion method to investigate their structural, optical, gas sensing, and photocatalytic properties. XRD and FTIR analyses confirmed the retention of the hexagonal wurtzite phase, with Mg doping slightly reducing the ‘c’ lattice parameter from 5.19 to 5.18 Å. Photoluminescence (PL) studies revealed an increase in bandgap from 3.2 eV (pure ZnO) to 3.4 eV (10% Mg-doped ZnO), indicating lattice distortion and band structure modification. High-resolution TEM images showed an increase in d-spacing with Mg content, while XPS analysis revealed hydroxide species and altered chemical states, confirming successful Mg incorporation and modified surface chemistry. An enhanced NBE–defect emission ratio (INBE/Idefect) from PL spectra demonstrated improved radiative recombination and suppressed non-radiative losses, enabling superior light-harvesting for gas sensing and photocatalysis. Gas sensing measurements showed significant improvement in NO₂ detection at 200 °C, with the response increasing from 72% for ZnO to 81% for Zn₀.₉₅Mg₀.₀₅O at 5 ppm NO₂. The Mg-doped sample also exhibited faster response (27 s), recovery (32 s), and superior selectivity. Photocatalytic tests using methylene blue (MB) dye under xenon light revealed enhanced degradation efficiencies of 84%, 87%, and 88% for Zn1−xMgxO with x = 0, 0.05, and 0.10, respectively, with the highest rate constant (0.01781 min−1) observed for 10% Mg doping. Improved performance is attributed to increased oxygen vacancies and enhanced charge separation. These results position Mg-doped ZnO as a promising multifunctional material for environmental remediation and gas sensing.