Electrochemical properties of vertically aligned graphenes: tailoring heterogeneous electron transfer through manipulation of the carbon microstructure
Por favor, use este identificador para citar o enlazar este ítem:
http://hdl.handle.net/10045/110479
Título: | Electrochemical properties of vertically aligned graphenes: tailoring heterogeneous electron transfer through manipulation of the carbon microstructure |
---|---|
Autor/es: | Brownson, Dale A.C. | Garcia-Miranda Ferrari, Alejandro | Ghosh, Subrata | Kamruddin, Mohammed | Iniesta, Jesus | Banks, Craig E. |
Grupo/s de investigación o GITE: | Electroquímica Aplicada y Electrocatálisis |
Centro, Departamento o Servicio: | Universidad de Alicante. Departamento de Química Física | Universidad de Alicante. Instituto Universitario de Electroquímica |
Palabras clave: | Electrochemical properties | Vertically aligned graphenes | Heterogeneous electron transfer | Carbon microstructure |
Área/s de conocimiento: | Química Física |
Fecha de publicación: | 6-oct-2020 |
Editor: | Royal Society of Chemistry |
Cita bibliográfica: | Nanoscale Advances. 2020, 2: 5319-5328. https://doi.org/10.1039/D0NA00587H |
Resumen: | The electrochemical response of different morphologies (microstructures) of vertically aligned graphene (VG) configurations is reported. Electrochemical properties are analysed using the outer-sphere redox probes Ru(NH3)62+/3+ (RuHex) and N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD), with performances de-convoluted via accompanying physicochemical characterisation (Raman, TEM, SEM, AFM and XPS). The VG electrodes are fabricated using an electron cyclotron resonance chemical vapour deposition (ECR-CVD) methodology, creating vertical graphene with a range of differing heights, spacing and edge plane like-sites/defects (supported upon underlying SiO2/Si). We correlate the electrochemical reactivity/response of these novel VG configurations with the level of edge plane sites (%-edge) comprising their structure and calculate corresponding heterogeneous electron transfer (HET) rates, k0. Taller VG structures with more condensed layer stacking (hence a larger global coverage of exposed edge plane sites) are shown to exhibit improved HET kinetics, supporting the claims that edge plane sites are the predominant source of electron transfer in carbon materials. A measured k0eff of ca. 4.00 × 10−3 cm s−1 (corresponding to an exposed surface coverage of active edge plane like-sites/defects (% θedge) of 1.00%) was evident for the tallest and most closely stacked VG sample, with the inverse case true, where a VG electrode possessing large inter-aligned-graphene spacing and small flake heights exhibited only 0.08% of % θedge and a k0eff value one order of magnitude slower at ca. 3.05 × 10−4 cm s−1. Control experiments are provided with conventional CVD (horizontal) grown graphene and the edge plane of highly ordered pyrolytic graphite (EPPG of HOPG), demonstrating that the novel VG electrodes exhibit ca. 3× faster k0 than horizontal CVD graphene. EPPG exhibited the fastest HET kinetics, exhibiting ca. 2× larger k0 than the best VG. These results are of significance to those working in the field of 2D-carbon electrochemistry and materials scientists, providing evidence that the macroscale electrochemical response of carbon-based electrodes is dependent on the edge plane content and showing that a range of structural configurations can be employed for tailored properties and applications. |
Patrocinador/es: | D. A. C. Brownson acknowledges funding from the Ramsay Memorial Fellowships Trust. Funding from the Engineering and Physical Science Research Council (Reference: EP/N001877/1), a British Council Institutional Grant Link (No. 172726574) and Innovate UK (KTP Reference: 11606) is acknowledged. |
URI: | http://hdl.handle.net/10045/110479 |
ISSN: | 2516-0230 |
DOI: | 10.1039/D0NA00587H |
Idioma: | eng |
Tipo: | info:eu-repo/semantics/article |
Derechos: | This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence |
Revisión científica: | si |
Versión del editor: | https://doi.org/10.1039/D0NA00587H |
Aparece en las colecciones: | INV - LEQA - Artículos de Revistas |
Archivos en este ítem:
Archivo | Descripción | Tamaño | Formato | |
---|---|---|---|---|
Brownson_etal_2020_NanoscaleAdv.pdf | 2,44 MB | Adobe PDF | Abrir Vista previa | |
Este ítem está licenciado bajo Licencia Creative Commons