Scholarlink

<p>Nickel ferrite (NiFe<sub>2</sub>O<sub>4</sub>) was synthesized via the co-precipitation method and thoroughly characterized to investigate its structural, optical, and dielectric properties for photocatalytic and optoelectronic applications. X-ray diffraction confirmed a highly crystalline spinel structure, while SEM and EDX analyses revealed a porous morphology that enhances surface-active sites. XPS analysis verified the oxidation states of Ni<sup>2+</sup> and Fe<sup>3+</sup>, which are crucial for charge transfer and catalytic activity. Diffuse reflectance spectroscopy determined a direct bandgap of 1.78&#xa0;eV, with a strong extinction coefficient (k) in the visible range and a high refractive index (n) peaking at 7 around 550&#xa0;nm. These properties indicate robust light absorption, efficient photon trapping, and enhanced optical path length, all of which are beneficial for photocatalytic applications. The dielectric analysis showed a high real dielectric constant (ε<sub>r</sub>) exceeding 50 at low photon energies, suggesting strong polarization capacity, while the imaginary dielectric constant (ε<sub>i</sub>) peaked around 2.5&#xa0;eV, confirming significant energy absorption and storage potential. Optical and electrical conductivity studies further demonstrated the material’s ability to transport charge efficiently, reducing recombination losses and improving photocatalytic performance. The dissipation factor (tan δ) indicated minimal energy loss, while the relaxation time (τ) analysis showed prolonged carrier lifetimes, ensuring sustained charge separation and enhanced catalytic efficiency. The photocatalytic activity of NiFe<sub>2</sub>O<sub>4</sub> was evaluated through the degradation of Rhodamine B under visible light, achieving a significant degradation efficiency with a rate constant of 0.00934&#xa0;min<sup>−1</sup>, markedly higher than that of photolysis alone. Scavenger tests revealed that photogenerated holes and electrons are the dominant active species, driving the degradation process through efficient redox reactions, while reusability studies confirmed the material's stability over multiple cycles. These findings establish NiFe<sub>2</sub>O<sub>4</sub> as a highly efficient material for photocatalysis and optoelectronics, with strong light-matter interactions, high charge mobility, and stable dielectric properties. Its ability to harness visible light effectively, sustain charge separation, and minimize energy loss makes it an excellent candidate for environmental remediation and energy conversion 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

Optical and dielectric properties of NiFe2O4 prepared by co-precipitation: correlation with photocatalytic performance for Rhodamine B degradation under visible light

  • 期刊论文

  • 发表日期：

    2025年5月15日

查看全文
  • K. Derkaoui,
  • I. Belkhettab,
  • I. Bencherifa,
  • A. Elfiad,
  • Y. Mebdoua,
  • K. Boukhouidem,
  • S. Benredouane,
  • S. Naama,
  • T. Hadjersi,
  • M. Kechouane

摘要

Nickel ferrite (NiFe2O4) was synthesized via the co-precipitation method and thoroughly characterized to investigate its structural, optical, and dielectric properties for photocatalytic and optoelectronic applications. X-ray diffraction confirmed a highly crystalline spinel structure, while SEM and EDX analyses revealed a porous morphology that enhances surface-active sites. XPS analysis verified the oxidation states of Ni2+ and Fe3+, which are crucial for charge transfer and catalytic activity. Diffuse reflectance spectroscopy determined a direct bandgap of 1.78 eV, with a strong extinction coefficient (k) in the visible range and a high refractive index (n) peaking at 7 around 550 nm. These properties indicate robust light absorption, efficient photon trapping, and enhanced optical path length, all of which are beneficial for photocatalytic applications. The dielectric analysis showed a high real dielectric constant (εr) exceeding 50 at low photon energies, suggesting strong polarization capacity, while the imaginary dielectric constant (εi) peaked around 2.5 eV, confirming significant energy absorption and storage potential. Optical and electrical conductivity studies further demonstrated the material’s ability to transport charge efficiently, reducing recombination losses and improving photocatalytic performance. The dissipation factor (tan δ) indicated minimal energy loss, while the relaxation time (τ) analysis showed prolonged carrier lifetimes, ensuring sustained charge separation and enhanced catalytic efficiency. The photocatalytic activity of NiFe2O4 was evaluated through the degradation of Rhodamine B under visible light, achieving a significant degradation efficiency with a rate constant of 0.00934 min−1, markedly higher than that of photolysis alone. Scavenger tests revealed that photogenerated holes and electrons are the dominant active species, driving the degradation process through efficient redox reactions, while reusability studies confirmed the material's stability over multiple cycles. These findings establish NiFe2O4 as a highly efficient material for photocatalysis and optoelectronics, with strong light-matter interactions, high charge mobility, and stable dielectric properties. Its ability to harness visible light effectively, sustain charge separation, and minimize energy loss makes it an excellent candidate for environmental remediation and energy conversion applications.