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Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction

[Image: see text] The development of nonprecious catalysts for water splitting into hydrogen and oxygen is one of the major challenges to meet future sustainable fuel demand. Herein, thin layers of manganese oxide nanosheets supported on nitrogen-functionalized carbon nanotubes (NCNTs) were formed b...

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Autores principales: Antoni, Hendrik, Morales, Dulce M., Fu, Qi, Chen, Yen-Ting, Masa, Justus, Schuhmann, Wolfgang, Muhler, Martin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2018
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645440/
https://www.ncbi.nlm.nih.gov/pubmed/31459231
http://dx.doi.org/10.1021/acsomega.8b01433
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author Antoni, Hendrik
Morales, Dulce M.
Fu, Qi
Chen, Yen-Ting
Masa, Justus
Schuhmann, Wolfgang
Muhler, Martin
author_facet Antoni, Hendrik
Morales, Dulce M.
Fu, Qi
Chen, Yen-Ting
Masa, Justus
Schuhmann, Wolfgang
Muhler, Martin
author_sort Antoni, Hendrik
collection PubMed
description [Image: see text] The development of nonprecious catalysts for water splitting into hydrogen and oxygen is one of the major challenges to meet future sustainable fuel demand. Herein, thin layers of manganese oxide nanosheets supported on nitrogen-functionalized carbon nanotubes (NCNTs) were formed by the treatment of NCNTs dispersed in aqueous solutions of KMnO(4) or CsMnO(4) under reflux or under hydrothermal (HT) conditions and used as electrocatalysts for the oxygen evolution reaction (OER) in alkaline media. The samples were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. Our results show that the NCNTs treated under reflux were covered by partly amorphous and birnessite-type manganese oxides, while predominantly crystalline birnessite manganese oxide was observed for the hydrothermally treated samples. The latter showed, depending on the temperature during synthesis, an electrocatalytically favorable reduction from birnessite-type MnO(2) to γ-MnOOH. OER activity measurements revealed a decrease of the overpotential for the OER at a current density of 10 mA cm(–2) from 1.70 V(RHE) for the bare NCNTs to 1.64 V(RHE) for the samples treated under reflux in the presence of KMnO(4). The hydrothermally treated samples afforded the same current density at a lower potential of 1.60 V(RHE) and a Tafel slope of 75 mV dec(–1), suggesting that the higher OER activity is due to γ-MnOOH formation. Oxidative deposition under reflux conditions using CsMnO(4) along with mild HT treatment using KMnO(4), and low manganese loadings in both cases, were identified as the most suitable synthetic routes to obtain highly active MnO(x)/NCNT catalysts for electrochemical water oxidation.
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spelling pubmed-66454402019-08-27 Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction Antoni, Hendrik Morales, Dulce M. Fu, Qi Chen, Yen-Ting Masa, Justus Schuhmann, Wolfgang Muhler, Martin ACS Omega [Image: see text] The development of nonprecious catalysts for water splitting into hydrogen and oxygen is one of the major challenges to meet future sustainable fuel demand. Herein, thin layers of manganese oxide nanosheets supported on nitrogen-functionalized carbon nanotubes (NCNTs) were formed by the treatment of NCNTs dispersed in aqueous solutions of KMnO(4) or CsMnO(4) under reflux or under hydrothermal (HT) conditions and used as electrocatalysts for the oxygen evolution reaction (OER) in alkaline media. The samples were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. Our results show that the NCNTs treated under reflux were covered by partly amorphous and birnessite-type manganese oxides, while predominantly crystalline birnessite manganese oxide was observed for the hydrothermally treated samples. The latter showed, depending on the temperature during synthesis, an electrocatalytically favorable reduction from birnessite-type MnO(2) to γ-MnOOH. OER activity measurements revealed a decrease of the overpotential for the OER at a current density of 10 mA cm(–2) from 1.70 V(RHE) for the bare NCNTs to 1.64 V(RHE) for the samples treated under reflux in the presence of KMnO(4). The hydrothermally treated samples afforded the same current density at a lower potential of 1.60 V(RHE) and a Tafel slope of 75 mV dec(–1), suggesting that the higher OER activity is due to γ-MnOOH formation. Oxidative deposition under reflux conditions using CsMnO(4) along with mild HT treatment using KMnO(4), and low manganese loadings in both cases, were identified as the most suitable synthetic routes to obtain highly active MnO(x)/NCNT catalysts for electrochemical water oxidation. American Chemical Society 2018-09-14 /pmc/articles/PMC6645440/ /pubmed/31459231 http://dx.doi.org/10.1021/acsomega.8b01433 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 Antoni, Hendrik
Morales, Dulce M.
Fu, Qi
Chen, Yen-Ting
Masa, Justus
Schuhmann, Wolfgang
Muhler, Martin
Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction
title Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction
title_full Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction
title_fullStr Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction
title_full_unstemmed Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction
title_short Oxidative Deposition of Manganese Oxide Nanosheets on Nitrogen-Functionalized Carbon Nanotubes Applied in the Alkaline Oxygen Evolution Reaction
title_sort oxidative deposition of manganese oxide nanosheets on nitrogen-functionalized carbon nanotubes applied in the alkaline oxygen evolution reaction
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645440/
https://www.ncbi.nlm.nih.gov/pubmed/31459231
http://dx.doi.org/10.1021/acsomega.8b01433
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