Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte

In this paper, titanium–dioxide (TiO2) nanotubes (TNTs) are formed by anodic oxidation with a fluorinated glycerol–water (85% and 15%, respectively) electrolyte to examine the effect of fluoride ion concentration, time, and applied voltage on TNT morphologies and dimensions. For fluoride ion concent...

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Published in:Catalysts
Main Author: Rosli S.A.; Alias N.; Bashirom N.; Ismail S.; Tan W.K.; Kawamura G.; Matsuda A.; Lockman Z.
Format: Article
Language:English
Published: MDPI 2021
Online Access:https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102429127&doi=10.3390%2fcatal11030376&partnerID=40&md5=c2ba868ad40c0f176a42ba71b4e15713
id 2-s2.0-85102429127
spelling 2-s2.0-85102429127
Rosli S.A.; Alias N.; Bashirom N.; Ismail S.; Tan W.K.; Kawamura G.; Matsuda A.; Lockman Z.
Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
2021
Catalysts
11
3
10.3390/catal11030376
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102429127&doi=10.3390%2fcatal11030376&partnerID=40&md5=c2ba868ad40c0f176a42ba71b4e15713
In this paper, titanium–dioxide (TiO2) nanotubes (TNTs) are formed by anodic oxidation with a fluorinated glycerol–water (85% and 15%, respectively) electrolyte to examine the effect of fluoride ion concentration, time, and applied voltage on TNT morphologies and dimensions. For fluoride ion concentration, the surface etching increases when the amount of ammonium fluoride added to the electrolyte solution increases, forming nanotube arrays with a clear pore structure. At a constant voltage of 20 V, TNTs with an average length of ~2 µm are obtained after anodization for 180 min. A prolonged anodization time only results in a marginal length increment. The TNT diameter is voltage dependent and increases from approximately 30 nm at 10 V to 310 nm at 60 V. At 80 V, the structure is destroyed. TNTs formed at 20 V for 180 min are annealed to induce the TiO2 anatase phase in either air or nitrogen. When ethylenediaminetetraacetic acid is added as a hole scavenger, 100% hexavalent chromium removal is obtained after 120 min of sunlight exposure for nitrogen-annealed TNTs. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
MDPI
20734344
English
Article
All Open Access; Gold Open Access; Green Open Access
author Rosli S.A.; Alias N.; Bashirom N.; Ismail S.; Tan W.K.; Kawamura G.; Matsuda A.; Lockman Z.
spellingShingle Rosli S.A.; Alias N.; Bashirom N.; Ismail S.; Tan W.K.; Kawamura G.; Matsuda A.; Lockman Z.
Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
author_facet Rosli S.A.; Alias N.; Bashirom N.; Ismail S.; Tan W.K.; Kawamura G.; Matsuda A.; Lockman Z.
author_sort Rosli S.A.; Alias N.; Bashirom N.; Ismail S.; Tan W.K.; Kawamura G.; Matsuda A.; Lockman Z.
title Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
title_short Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
title_full Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
title_fullStr Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
title_full_unstemmed Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
title_sort Hexavalent chromium removal via photoreduction by sunlight on titanium–dioxide nanotubes formed by anodization with a fluorinated glycerol–water electrolyte
publishDate 2021
container_title Catalysts
container_volume 11
container_issue 3
doi_str_mv 10.3390/catal11030376
url https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102429127&doi=10.3390%2fcatal11030376&partnerID=40&md5=c2ba868ad40c0f176a42ba71b4e15713
description In this paper, titanium–dioxide (TiO2) nanotubes (TNTs) are formed by anodic oxidation with a fluorinated glycerol–water (85% and 15%, respectively) electrolyte to examine the effect of fluoride ion concentration, time, and applied voltage on TNT morphologies and dimensions. For fluoride ion concentration, the surface etching increases when the amount of ammonium fluoride added to the electrolyte solution increases, forming nanotube arrays with a clear pore structure. At a constant voltage of 20 V, TNTs with an average length of ~2 µm are obtained after anodization for 180 min. A prolonged anodization time only results in a marginal length increment. The TNT diameter is voltage dependent and increases from approximately 30 nm at 10 V to 310 nm at 60 V. At 80 V, the structure is destroyed. TNTs formed at 20 V for 180 min are annealed to induce the TiO2 anatase phase in either air or nitrogen. When ethylenediaminetetraacetic acid is added as a hole scavenger, 100% hexavalent chromium removal is obtained after 120 min of sunlight exposure for nitrogen-annealed TNTs. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
publisher MDPI
issn 20734344
language English
format Article
accesstype All Open Access; Gold Open Access; Green Open Access
record_format scopus
collection Scopus
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