Electrostatic Control over the Electrochemical Reactivity of Graphene

Kai Wen Chang, Ian Alvarez Santos, Yen Nguyen, Yen Hsun Su, Chia Chen Hsu, Ya Ping Hsieh, Mario Hofmann

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

Graphene has shown great potential as electrochemical electrodes in energy storage and sensor applications due to its unique combination of semiconducting and metallic properties. We here demonstrate that graphene's semimetallic nature imparts it with a continuously tunable electrochemical reactivity. Extrinsic doping was shown to modify the reaction rate of graphene microelectrode arrays and a direct correlation between graphene's linearly varying density of states and its electron transfer rate was established. Dynamic control of the charge transfer process enabled the variation of graphene's reaction rate over 1 order of magnitude and was confirmed by a simple Gerischer-Marcus charge transfer kinetics model. The observed fine control over graphene's electrochemical properties enabled a 2-fold increase in the resolution of an electrochemical impedance sensor. These results not only explain previous observations of graphene's spatially varying electrochemical reactivity and highlight the importance of doping control in graphene-based electrochemical applications but also open up exciting routes for combining electronics and electrochemistry in novel sensors and actuators.

Original languageEnglish
Pages (from-to)7178-7182
Number of pages5
JournalChemistry of Materials
Volume30
Issue number20
DOIs
Publication statusPublished - 2018 Oct 23

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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