Scholarlink

<p>Plasma electrolytic oxidation (PEO) is a derivative method of conventional anodization. In this process, the anodic oxide layer formed on the anode is subjected to a high electrical field. This leads to dielectric breakdown and ignites plasma micro-arcs across the anodized surface, thereby altering the formation of the oxide layer. This work presents the results of an investigation into the influence of the electrolyte composition on the electrochemical response of Nb<sub>2</sub>O<sub>5</sub> films produced under the PEO regime, as well as the coating’s photocatalytic properties against dye degradation under UV light. Niobium substrates were anodized in an acid medium (C<sub>2</sub>H<sub>2</sub>O<sub>4</sub> and H<sub>3</sub>PO<sub>4</sub>) and an alkaline medium (KOH) using a DC power source in galvanostatic mode and electrolyte temperature control. The samples were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). During the PEO synthesis process using different types of electrolytes, distinct behaviors were observed in the temperature and voltage (V) vs. time (s) curves, indicating variations in surface composition. The photoactivity of the samples was investigated through photodegradation tests of aqueous solutions of Methylene Blue (MB) and Rhodamine B (RhB) under UV light. The results showed that the sample anodized with an electrolyte containing 0.1&#xa0;mol L<sup>−1</sup> of C<sub>2</sub>H<sub>2</sub>O<sub>4</sub> exhibited higher photoactivity mainly due to the surface of the film having a larger portion of Nb<sub>2</sub>O<sub>5</sub> compared to the other samples. Sample Nb_C<sub>2</sub>H<sub>2</sub>O<sub>4</sub> also exhibits the lowest charge transfer resistance, indicating a more efficient interface for charge transfer.</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

Influence of the electrolyte solution compositions on the synthesis and photocatalytic properties of Nb2O5 films obtained by plasma electrolytic oxidation

  • 期刊论文

  • 发表日期：

    2026年1月5日

查看全文
  • Patrícia S. Araújo,
  • Yasmin B. Pissolitto,
  • Jonata R. D. Batista,
  • Vagner R. de Mendonça,
  • Francisco Trivinho-Strixino

摘要

Plasma electrolytic oxidation (PEO) is a derivative method of conventional anodization. In this process, the anodic oxide layer formed on the anode is subjected to a high electrical field. This leads to dielectric breakdown and ignites plasma micro-arcs across the anodized surface, thereby altering the formation of the oxide layer. This work presents the results of an investigation into the influence of the electrolyte composition on the electrochemical response of Nb2O5 films produced under the PEO regime, as well as the coating’s photocatalytic properties against dye degradation under UV light. Niobium substrates were anodized in an acid medium (C2H2O4 and H3PO4) and an alkaline medium (KOH) using a DC power source in galvanostatic mode and electrolyte temperature control. The samples were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). During the PEO synthesis process using different types of electrolytes, distinct behaviors were observed in the temperature and voltage (V) vs. time (s) curves, indicating variations in surface composition. The photoactivity of the samples was investigated through photodegradation tests of aqueous solutions of Methylene Blue (MB) and Rhodamine B (RhB) under UV light. The results showed that the sample anodized with an electrolyte containing 0.1 mol L−1 of C2H2O4 exhibited higher photoactivity mainly due to the surface of the film having a larger portion of Nb2O5 compared to the other samples. Sample Nb_C2H2O4 also exhibits the lowest charge transfer resistance, indicating a more efficient interface for charge transfer.

Graphical Abstract