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Soft Processing of Graphene Nanosheets by Glycine‐Bisulfate Ionic‐Complex‐Assisted Electrochemical Exfoliation of Graphite for Reduction Catalysis
Author(s) -
Rao Kodepelly Sanjeeva,
Sentilnathan Jaganathan,
Cho HsunWei,
Wu JihJen,
Yoshimura Masahiro
Publication year - 2015
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201402621
Subject(s) - graphene , materials science , exfoliation joint , intercalation (chemistry) , electrochemistry , graphite , ionic liquid , inorganic chemistry , sulfuric acid , chemical engineering , catalysis , nanotechnology , organic chemistry , electrode , chemistry , composite material , engineering , metallurgy
This study demonstrates a mild, environmentally friendly, and cost‐effective soft processing approach for the continuous synthesis of high‐quality, few‐layer graphene nanosheets. This has been achieved via electrochemical exfoliation of graphite, using an environmentally friendly glycine‐bisulfate ionic complex and was performed under ambient reaction conditions. Graphene nanosheets with 2–5 layers were obtained under optimized exfoliation conditions using a 15 wt% glycine‐bisulfate (aqueous) solution, with working biases of +1 V and +3 V applied for 5 min. The role of the glycine‐bisulfate ionic complex in the electrochemical exfoliation process was confirmed through comparison with a control experiment using only sulfuric acid as the electrolyte. A plausible electrochemical exfoliation mechanism that involves the formation of surface molecule nuclei via the polymerization of intercalated monomeric HSO 4 − and SO 4 2− ions is proposed. The ionic complex plays a key role in the anodic graphite exfoliation via electrochemical‐potential‐induced intercalation, leading to an efficient expansion of graphite sheets via the insertion of oxygen functional groups.