Effect of graphene flake size on functionalisation: quantifying reaction extent and imaging locus with single Pt atom tags
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Here, the locus of functionalisation on graphene-related materials and the progress of the reaction is shown to depend strongly on the starting feedstock. Five characteristically different graphite sources were exfoliated and functionalized using a non-destructive chemical reduction method. These archetypical examples were compared via a model reaction, grafting dodecyl addends, evaluated with TGA-MS, XPS and Raman data. A general increase in grafting ratio (ranging from 1.1 wt% up to 25 wt%) and an improvement in grafting stoichiometry (C/R) were observed as flake radius decreased. Raman spectrum imaging of the functionalised natural flake graphite identified that grafting is directed towards flake edges. This behaviour was further corroborated, at atomistic resolution, by functionalising the graphene layers with bipyridine groups able to complex single platinum atoms. The distribution of these groups was then directly imaged using aberration-corrected HAADF-STEM. Platinum atoms were found to be homogeneously distributed across smaller graphenes; in contrast, a more heterogeneous distribution, with a predominance of edge grafting was observed for larger graphites. These observations show that grafting is directed towards flake edges, but not necessary at edge sites; the mechanism is attributed to the relative inaccessibility of the inner basal plane to reactive moieties, resulting in kinetically driven grafting nearer flake edges. This phenomenology may be relevant to a wide range of reactions on graphenes and other 2d materials.
Date Issued
2021-10-21
Date Acceptance
2021-10-20
Citation
Chemical Science, 2021, 12 (44), pp.1-13
ISSN
2041-6520
Publisher
Royal Society of Chemistry
Start Page
1
End Page
13
Journal / Book Title
Chemical Science
Volume
12
Issue
44
Copyright Statement
© 2021 The Author(s). Published by the Royal Society of Chemistry. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
License URL
Sponsor
Commission of the European Communities
Commission of the European Communities
Commission of the European Communities
Identifier
https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000714701800001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
696656
785219
881603
Subjects
Science & Technology
Physical Sciences
Chemistry, Multidisciplinary
Chemistry
RAMAN-SPECTROSCOPY
LAYER GRAPHENE
DEFECTS
EXFOLIATION
Publication Status
Published
Date Publish Online
2021-10-20