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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Tuning Vertical Electron Transfer on Graphene Bilayer Electrochemical Devices

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Sanches, Natalia M. [1] ; Hassan, Ayaz [1] ; Mattioli, Isabela A. [1] ; Macedo, Lucyano J. A. [1] ; Sedenho, Graziela C. [1] ; Crespilho, Frank N. [1]
Total Authors: 6
[1] Univ Sao Paulo, Sao Carlos Inst Chem, BR-13560970 Sao Carlos, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Web of Science Citations: 0

Pristine graphene electrodes exhibit slow vertical (off-plane) heterogeneous electron transfer (HET) rate that limits their application in electrochemical devices. This can be minimized by generating defects in the graphene structure. However, these defects adversely affect the horizontal (in-plane) electrical conductivity characteristic to graphene. Here, the fabrication of graphene bilayer devices with modulated vertical HET is reported. Strategically, the upper sheet is used as a sacrificial layer for the introduction of extrinsic defects via electrochemical oxidation while preserving the structure of the graphene underlying layer. For {[}Fe(CN)(6)](4-)/{[}Fe(CN)(6)](3-) vertical HET in solution-phase, oxidized electrodes present a very low charge transfer resistance. For vertical HET in surface adsorbed ferrocene on oxidized electrodes, the vertical HET rate constant is about five times higher than on pristine electrodes. Based on data from scattering-type scanning near-field optical microscopy (s-SNOM) and Raman spectroscopy, the improvement on the electrochemical properties is attributed to the defects that are incorporated in the upper layer graphene lattice. This fundamental study on the atomic behavior of defects and stacking layers of graphene provides a new strategic design of graphene-based devices with superior electrochemical performance. (AU)

FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
Grantee:Osvaldo Novais de Oliveira Junior
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 17/20493-2 - Study of metalloenzymes through electrochemistry coupled to vibrational spectroscopy
Grantee:Lucyano Jefferson Alves de Macêdo
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 19/15333-1 - Bio-photo-electrochemical hybrid cells for solar energy conversion
Grantee:Frank Nelson Crespilho
Support Opportunities: Regular Research Grants
FAPESP's process: 19/12053-8 - High performance electrodes applied in organic batteries and in biofuel cell
Grantee:Frank Nelson Crespilho
Support Opportunities: Regular Research Grants
FAPESP's process: 15/22973-6 - Development of Microbial Fuel Biocells for Bioproduction and Oxidation of Ethanol
Grantee:Graziela Cristina Sedenho
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 18/11071-0 - Development and application of disposable screen-printed composite electrodes based on metallic nanoparticles and graphite-polyurethane
Grantee:Isabela Alteia Mattioli
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)