Perspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitance

Abstract This perspective presents a combined experimental-theory investigation of the mechanistic outer-sphere electron transfer (OS-ET) kinetics in an adiabatic regime for a cornerstone electrochemical reaction, fundamental to efficient energy interconversion as in electrochemical double layer sup...

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Main Authors: Sanju Gupta, Magdalena Narajczyk, Mirosław Sawczak, Robert Bogdanowicz
Format: Article
Language:English
Published: Nature Portfolio 2025-06-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-04357-x
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author Sanju Gupta
Magdalena Narajczyk
Mirosław Sawczak
Robert Bogdanowicz
author_facet Sanju Gupta
Magdalena Narajczyk
Mirosław Sawczak
Robert Bogdanowicz
author_sort Sanju Gupta
collection DOAJ
description Abstract This perspective presents a combined experimental-theory investigation of the mechanistic outer-sphere electron transfer (OS-ET) kinetics in an adiabatic regime for a cornerstone electrochemical reaction, fundamental to efficient energy interconversion as in electrochemical double layer supercapacitors, across graphene-family nanomaterials (GFNs) ranging from pristine graphene to nitrogen-doped graphene aerogel and the novel laser-induced graphene. Using scanning electrochemical microscopy (SECM) operating in feedback mode and co-located spectroscopy, the ET rate constant, k 0 (or k ET, cm/s) was quantified while imaging electroactivity of potassium hexacyanoferrate (III/IV) [Fe (CN) 6 4−/3−] or ferrocene methanol [Fc 0 /Fc +] redox probe yielding unexpected trends. We examined factors affecting the kinetic rate constant, rationalized through a physical model and parameterized using density functional theory by incorporating defects and dopants. We attributed the improved kinetic rates (0.01–0.1 via SECM) compared with ensemble-averaged method (0.001–0.01 cm/s) to point-like topological defects in basal plane (number density ~ 1012/cm2), oxygen functional groups (C/O ratio: 4:1–12:1), nitrogen doping, and edge plane hydrogen-bonding sites (density: 0.1–1.0 μm−1), altering the electronic structure factored into available density of states near Fermi level (− 0.2 to  + 0.2 eV), and quantum capacitance. We elucidated the ET kinetics tunability by engineering the electronic band structure, varying electrode potential, and morphological diversity.
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spelling doaj-art-d6e3a2e92bf040cf9ff1a061cb87e3e92025-08-20T03:10:35ZengNature PortfolioScientific Reports2045-23222025-06-0115112710.1038/s41598-025-04357-xPerspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitanceSanju Gupta0Magdalena Narajczyk1Mirosław Sawczak2Robert Bogdanowicz3Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunication and Informatics, Gdansk University of TechnologyFaculty of Biology, Bioimaging Laboratory, University of GdanskThe Szewalski Institute of Fluid-Flow Machinery, Polish Academy of SciencesDepartment of Metrology and Optoelectronics, Faculty of Electronics, Telecommunication and Informatics, Gdansk University of TechnologyAbstract This perspective presents a combined experimental-theory investigation of the mechanistic outer-sphere electron transfer (OS-ET) kinetics in an adiabatic regime for a cornerstone electrochemical reaction, fundamental to efficient energy interconversion as in electrochemical double layer supercapacitors, across graphene-family nanomaterials (GFNs) ranging from pristine graphene to nitrogen-doped graphene aerogel and the novel laser-induced graphene. Using scanning electrochemical microscopy (SECM) operating in feedback mode and co-located spectroscopy, the ET rate constant, k 0 (or k ET, cm/s) was quantified while imaging electroactivity of potassium hexacyanoferrate (III/IV) [Fe (CN) 6 4−/3−] or ferrocene methanol [Fc 0 /Fc +] redox probe yielding unexpected trends. We examined factors affecting the kinetic rate constant, rationalized through a physical model and parameterized using density functional theory by incorporating defects and dopants. We attributed the improved kinetic rates (0.01–0.1 via SECM) compared with ensemble-averaged method (0.001–0.01 cm/s) to point-like topological defects in basal plane (number density ~ 1012/cm2), oxygen functional groups (C/O ratio: 4:1–12:1), nitrogen doping, and edge plane hydrogen-bonding sites (density: 0.1–1.0 μm−1), altering the electronic structure factored into available density of states near Fermi level (− 0.2 to  + 0.2 eV), and quantum capacitance. We elucidated the ET kinetics tunability by engineering the electronic band structure, varying electrode potential, and morphological diversity.https://doi.org/10.1038/s41598-025-04357-xGFNsLaser-induced grapheneSECMElectron transferElectroactivityQuantum capacitance
spellingShingle Sanju Gupta
Magdalena Narajczyk
Mirosław Sawczak
Robert Bogdanowicz
Perspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitance
Scientific Reports
GFNs
Laser-induced graphene
SECM
Electron transfer
Electroactivity
Quantum capacitance
title Perspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitance
title_full Perspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitance
title_fullStr Perspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitance
title_full_unstemmed Perspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitance
title_short Perspectives on electron transfer kinetics across graphene-family nanomaterials and interplay of electronic structure with defects and quantum capacitance
title_sort perspectives on electron transfer kinetics across graphene family nanomaterials and interplay of electronic structure with defects and quantum capacitance
topic GFNs
Laser-induced graphene
SECM
Electron transfer
Electroactivity
Quantum capacitance
url https://doi.org/10.1038/s41598-025-04357-x
work_keys_str_mv AT sanjugupta perspectivesonelectrontransferkineticsacrossgraphenefamilynanomaterialsandinterplayofelectronicstructurewithdefectsandquantumcapacitance
AT magdalenanarajczyk perspectivesonelectrontransferkineticsacrossgraphenefamilynanomaterialsandinterplayofelectronicstructurewithdefectsandquantumcapacitance
AT mirosławsawczak perspectivesonelectrontransferkineticsacrossgraphenefamilynanomaterialsandinterplayofelectronicstructurewithdefectsandquantumcapacitance
AT robertbogdanowicz perspectivesonelectrontransferkineticsacrossgraphenefamilynanomaterialsandinterplayofelectronicstructurewithdefectsandquantumcapacitance