Porous structure obtained by anodizing niobium in NaOH

Porous structures can be produced as nanotubes, nanowires and membranes, and they can be used in gas sensors, magnetic and electronic devices, biotechnology, etc. These structures can be obtained by the anodizing process, in which the electrolyte must etch the oxide to occur the pore formation. In t...

Full description

Saved in:
Bibliographic Details
Published in:Tecnologia em metalurgia, materiais e mineração Vol. 18; p. e2046
Main Authors: Rocha, Rafael Martins da, Scheffel, Leonardo Felix, Carone, Carlos Leonardo Pandolfo, Morisso, Fernando Dal Pont, Kunst, Sandra Raquel, Ferreira, Jane Zoppas, Oliveira, Cláudia Trindade
Format: Journal Article
Language:English
Published: Sao Paulo Associação Brasileira de Metalurgia, Materiais e Mineração 2021
Subjects:
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Porous structures can be produced as nanotubes, nanowires and membranes, and they can be used in gas sensors, magnetic and electronic devices, biotechnology, etc. These structures can be obtained by the anodizing process, in which the electrolyte must etch the oxide to occur the pore formation. In the case of niobium, porous oxides have been obtained successfully in electrolytes containing hydrofluoric acid (HF). However, studies have shown that niobium dissolves in electrolytes of NaOH with pH 14, and porous oxides of niobium have already been obtained by the anodizing process with the occurrence of sparking. Thus, the objective of this work is to obtain porous oxides on Nb without HF addition by studying the sparking phenomenon. Therefore, niobium was anodized at different current densities (10, 25, 50, 75 and 100 mA.cm-2). The samples were evaluated concerning morphology by SEM and chemical microanalysis by EDS. It was observed that sparking depends of the oxide barrier thickness and occurs at current densities higher than 50mA.cm-2. However, the increase of the current density, in spite of not increasing the thickness of the barrier layer, caused a greater incidence of sparking. According to the assignment proposed it was possible to obtain a porous structure in niobium with NaOH electrolyte, but this structure got an irregular aspect
ISSN:2176-1515
2176-1523
DOI:10.4322/2176-1523.20212046