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Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties

[Image: see text] This paper reports the synthesis of two-dimensional, hierarchical, porous, and (001)-faceted metal (Ag, Zn, and Al)-doped TiO(2) nanostructures (TNSs) and the study of their photocatalytic activity. Two-dimensional metal-doped TNSs were synthesized using the hydrolysis of ammonium...

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Autores principales: Md Saad, Siti Khatijah, Ali Umar, Akrajas, Ali Umar, Marjoni Imamora, Tomitori, Masahiko, Abd. Rahman, Mohd. Yusri, Mat Salleh, Muhamad, Oyama, Munetaka
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2018
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6641261/
https://www.ncbi.nlm.nih.gov/pubmed/31458546
http://dx.doi.org/10.1021/acsomega.8b00109
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author Md Saad, Siti Khatijah
Ali Umar, Akrajas
Ali Umar, Marjoni Imamora
Tomitori, Masahiko
Abd. Rahman, Mohd. Yusri
Mat Salleh, Muhamad
Oyama, Munetaka
author_facet Md Saad, Siti Khatijah
Ali Umar, Akrajas
Ali Umar, Marjoni Imamora
Tomitori, Masahiko
Abd. Rahman, Mohd. Yusri
Mat Salleh, Muhamad
Oyama, Munetaka
author_sort Md Saad, Siti Khatijah
collection PubMed
description [Image: see text] This paper reports the synthesis of two-dimensional, hierarchical, porous, and (001)-faceted metal (Ag, Zn, and Al)-doped TiO(2) nanostructures (TNSs) and the study of their photocatalytic activity. Two-dimensional metal-doped TNSs were synthesized using the hydrolysis of ammonium hexafluorotitanate in the presence of hexamethylenetetramine and metal precursors. Typical morphology of metal-doped TNSs is a hierarchical nanosheet that is composed of randomly stacked nanocubes (dimensions of up to 5 μm and 200 nm in edge length and thickness, respectively) and has dominant (001) facets exposed. Raman analysis and X-ray photoelectron spectroscopy results indicated that the Ag doping, compared to Zn and Al, much improves the crystallinity degree and at the same time dramatically lowers the valence state binding energy of the TNS and provides an additional dopant oxidation state into the system for an enhanced electron-transfer process and surface reaction. These are assumed to enhance the photocatalytic of the TNS. In a model of photocatalytic reaction, that is, rhodamine B degradation, the AgTNS demonstrates a high photocatalytic activity by converting approximately 91% of rhodamine B within only 120 min, equivalent to a rate constant of 0.018 m(–1) and ToN and ToF of 94 and 1.57 min(–1), respectively, or 91.1 mmol mg(–1) W(–1) degradation when normalized to used light source intensity, which is approximately 2 times higher than the pristine TNS and several order higher when compared to Zn- and Al-doped TNSs. Improvement of the crystallinity degree, decrease in the defect density and the photogenerated electron and hole recombination, and increase of the oxygen vacancy in the AgTNS are found to be the key factors for the enhancement of the photocatalytic properties. This work provides a straightforward strategy for the preparation of high-energy (001) faceted, two-dimensional, hierarchical, and porous Ag-doped TNSs for potential use in photocatalysis and photoelectrochemical application.
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spelling pubmed-66412612019-08-27 Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties Md Saad, Siti Khatijah Ali Umar, Akrajas Ali Umar, Marjoni Imamora Tomitori, Masahiko Abd. Rahman, Mohd. Yusri Mat Salleh, Muhamad Oyama, Munetaka ACS Omega [Image: see text] This paper reports the synthesis of two-dimensional, hierarchical, porous, and (001)-faceted metal (Ag, Zn, and Al)-doped TiO(2) nanostructures (TNSs) and the study of their photocatalytic activity. Two-dimensional metal-doped TNSs were synthesized using the hydrolysis of ammonium hexafluorotitanate in the presence of hexamethylenetetramine and metal precursors. Typical morphology of metal-doped TNSs is a hierarchical nanosheet that is composed of randomly stacked nanocubes (dimensions of up to 5 μm and 200 nm in edge length and thickness, respectively) and has dominant (001) facets exposed. Raman analysis and X-ray photoelectron spectroscopy results indicated that the Ag doping, compared to Zn and Al, much improves the crystallinity degree and at the same time dramatically lowers the valence state binding energy of the TNS and provides an additional dopant oxidation state into the system for an enhanced electron-transfer process and surface reaction. These are assumed to enhance the photocatalytic of the TNS. In a model of photocatalytic reaction, that is, rhodamine B degradation, the AgTNS demonstrates a high photocatalytic activity by converting approximately 91% of rhodamine B within only 120 min, equivalent to a rate constant of 0.018 m(–1) and ToN and ToF of 94 and 1.57 min(–1), respectively, or 91.1 mmol mg(–1) W(–1) degradation when normalized to used light source intensity, which is approximately 2 times higher than the pristine TNS and several order higher when compared to Zn- and Al-doped TNSs. Improvement of the crystallinity degree, decrease in the defect density and the photogenerated electron and hole recombination, and increase of the oxygen vacancy in the AgTNS are found to be the key factors for the enhancement of the photocatalytic properties. This work provides a straightforward strategy for the preparation of high-energy (001) faceted, two-dimensional, hierarchical, and porous Ag-doped TNSs for potential use in photocatalysis and photoelectrochemical application. American Chemical Society 2018-03-05 /pmc/articles/PMC6641261/ /pubmed/31458546 http://dx.doi.org/10.1021/acsomega.8b00109 Text en Copyright © 2018 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Md Saad, Siti Khatijah
Ali Umar, Akrajas
Ali Umar, Marjoni Imamora
Tomitori, Masahiko
Abd. Rahman, Mohd. Yusri
Mat Salleh, Muhamad
Oyama, Munetaka
Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties
title Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties
title_full Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties
title_fullStr Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties
title_full_unstemmed Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties
title_short Two-Dimensional, Hierarchical Ag-Doped TiO(2) Nanocatalysts: Effect of the Metal Oxidation State on the Photocatalytic Properties
title_sort two-dimensional, hierarchical ag-doped tio(2) nanocatalysts: effect of the metal oxidation state on the photocatalytic properties
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6641261/
https://www.ncbi.nlm.nih.gov/pubmed/31458546
http://dx.doi.org/10.1021/acsomega.8b00109
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