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The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins

Hydrogen, considered to be an alternative fuel to traditional fossil fuels, can be generated by splitting water molecules into hydrogen and oxygen via the use of electrical energy, in a process whose efficiency depends directly on the employed catalytic material. The current study takes part in the...

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Autores principales: Taranu, Bogdan-Ovidiu, Fagadar-Cosma, Eugenia
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9656975/
https://www.ncbi.nlm.nih.gov/pubmed/36364562
http://dx.doi.org/10.3390/nano12213788
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author Taranu, Bogdan-Ovidiu
Fagadar-Cosma, Eugenia
author_facet Taranu, Bogdan-Ovidiu
Fagadar-Cosma, Eugenia
author_sort Taranu, Bogdan-Ovidiu
collection PubMed
description Hydrogen, considered to be an alternative fuel to traditional fossil fuels, can be generated by splitting water molecules into hydrogen and oxygen via the use of electrical energy, in a process whose efficiency depends directly on the employed catalytic material. The current study takes part in the relentless search for suitable and low-cost catalysts relevant to the water-splitting field by investigating the electrocatalytic properties of the O(2) and H(2) evolution reactions (OER and HER) of two metalloporphyrins: Zn(II) 5,10,15,20-tetrakis(4-pyridyl)-porphyrin and Co(II) 5,10,15,20-tetrakis(3-hydroxyphenyl)-porphyrin. The TEM/STEM characterisation of the porphyrin samples obtained using different organic solvents revealed several types of self-assembled aggregates. The HER and OER experiments performed on porphyrin-modified graphite electrodes in media with different pH values revealed the most electrocatalytically active specimens. For the OER, this specimen was the electrode manufactured with one layer of Co-porphyrin applied from dimethylsulfoxide, exhibiting an overpotential of 0.51 V at i = 10 mA/cm(2) and a Tafel slope of 0.27 V/dec. For the HER, it was the sample obtained by drop casting one layer of Zn-porphyrin from N,N-dimethylformamide that displayed a HER overpotential of 0.52 V at i = −10 mA/cm(2) and a Tafel slope of 0.15 V/dec.
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spelling pubmed-96569752022-11-15 The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins Taranu, Bogdan-Ovidiu Fagadar-Cosma, Eugenia Nanomaterials (Basel) Article Hydrogen, considered to be an alternative fuel to traditional fossil fuels, can be generated by splitting water molecules into hydrogen and oxygen via the use of electrical energy, in a process whose efficiency depends directly on the employed catalytic material. The current study takes part in the relentless search for suitable and low-cost catalysts relevant to the water-splitting field by investigating the electrocatalytic properties of the O(2) and H(2) evolution reactions (OER and HER) of two metalloporphyrins: Zn(II) 5,10,15,20-tetrakis(4-pyridyl)-porphyrin and Co(II) 5,10,15,20-tetrakis(3-hydroxyphenyl)-porphyrin. The TEM/STEM characterisation of the porphyrin samples obtained using different organic solvents revealed several types of self-assembled aggregates. The HER and OER experiments performed on porphyrin-modified graphite electrodes in media with different pH values revealed the most electrocatalytically active specimens. For the OER, this specimen was the electrode manufactured with one layer of Co-porphyrin applied from dimethylsulfoxide, exhibiting an overpotential of 0.51 V at i = 10 mA/cm(2) and a Tafel slope of 0.27 V/dec. For the HER, it was the sample obtained by drop casting one layer of Zn-porphyrin from N,N-dimethylformamide that displayed a HER overpotential of 0.52 V at i = −10 mA/cm(2) and a Tafel slope of 0.15 V/dec. MDPI 2022-10-27 /pmc/articles/PMC9656975/ /pubmed/36364562 http://dx.doi.org/10.3390/nano12213788 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Taranu, Bogdan-Ovidiu
Fagadar-Cosma, Eugenia
The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins
title The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins
title_full The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins
title_fullStr The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins
title_full_unstemmed The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins
title_short The pH Influence on the Water-Splitting Electrocatalytic Activity of Graphite Electrodes Modified with Symmetrically Substituted Metalloporphyrins
title_sort ph influence on the water-splitting electrocatalytic activity of graphite electrodes modified with symmetrically substituted metalloporphyrins
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9656975/
https://www.ncbi.nlm.nih.gov/pubmed/36364562
http://dx.doi.org/10.3390/nano12213788
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