Nanoscale Electrocatalysis of Hydrazine Electro-Oxidation at Blistered Graphite Electrodes

E. P. Sharel, Yang Rae Kim, David Perry, Cameron L. Bentley, Patrick R. Unwin

Research output: Contribution to journalArticleResearchpeer-review

28 Citations (Scopus)

Abstract

There is great interest in finding and developing new, efficient, and more active electrocatalytic materials. Surface modification of highly oriented pyrolytic graphite, through the introduction of surface "blisters", is demonstrated to result in an electrode material with greatly enhanced electrochemical activity. The increased electrochemical activity of these blisters, which are produced by electro-oxidation in HClO4, is revealed through the use of scanning electrochemical cell microscopy (SECCM), coupled with complementary techniques (optical microscopy, field emission-scanning electron microscopy, Raman spectroscopy, and atomic force microscopy). The use of a linear sweep voltammetry (LSV)-SECCM scan regime allows for dynamic electrochemical mapping, where a voltammogram is produced at each pixel, from which movies consisting of spatial electrochemical currents, at a series of applied potentials, are produced. The measurements reveal significantly enhanced electrocatalytic activity at blisters when compared to the basal planes, with a significant cathodic shift in the onset potential of the hydrazine electro-oxidation reaction. The improved electrochemical activity of the hollow structure of blistered graphite could be explained by the increased adsorption of protonated hydrazine at oxygenated defect sites, the ease of ion-solvent intercalation/deintercalation, and the reduced susceptibility to N2 nanobubble attachment (as a product of the reaction). This study highlights the capability of electrochemistry to tailor the surface structure of graphite and presents a new electrocatalyst for hydrazine electro-oxidation.

Original languageEnglish
Pages (from-to)30458-30466
Number of pages9
JournalACS Applied Materials & Interfaces
Volume8
Issue number44
DOIs
Publication statusPublished - 9 Nov 2016
Externally publishedYes

Keywords

  • electrocatalysis
  • graphite
  • hydrazine oxidation
  • nanoelectrochemistry
  • scanning electrochemical cell microscopy

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