New advances in ohmic microscopy

Zhange Feng, Nicholas S. Georgescu, Daniel Alberto Scherson

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

A series of electrochemical measurements involving metal disks, ring-disks and facetted single crystals in aqueous 0.1 M H2SO4 have been performed to monitor differences in the electrostatic potential in the electrolyte, Δϕsol, induced by the passage of current, and thus assess the prospects of ohmic microscopy as an in situ imaging tool of electrodes in solution. Excellent quantitative agreement was found between the experimental values of Δϕsol and those predicted by theory for current pulses several milliamperes in magnitude and tens of microseconds in duration, applied to a Pt disk electrode embedded in a coplanar insulating surface, assuming a strict primary current distribution. Cyclic voltammetry measurements involving a gapless Pt–Ir ring|Au disk electrode yielded Δϕsol versus potential, E, curves, consistent with contributions derived from each of the two electrodes assuming a uniform current distribution. Also explored were extensions of ohmic microscopy to the study of facetted Pt single crystals using microreference electrodes housed in a double barrel capillary. Data collected in voltammetric experiments in which the tip of the capillary was placed directly above and at very close distance from one of the (111) facets recorded with the entire single crystal immersed in the electrolyte, yielded Δϕsol vs. E curves displaying pronounced features believed to be characteristic of that surface. Possible strategies toward improving the spatial resolution of this emerging technique are also discussed.

Original languageEnglish
Pages (from-to)1003-1010
Number of pages8
JournalRussian Journal of Electrochemistry
Volume53
Issue number9
DOIs
Publication statusPublished - 2017 Sep 1
Externally publishedYes

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Polymethyl Methacrylate
Microscopic examination
Sols
Electrodes
Single crystals
Electrolytes
Cyclic voltammetry
Electrostatics
Metals
Imaging techniques
Experiments

Keywords

  • disc electrode
  • facetted single crystals
  • ohmic microscopy
  • ring-disk electrode

ASJC Scopus subject areas

  • Electrochemistry

Cite this

New advances in ohmic microscopy. / Feng, Zhange; Georgescu, Nicholas S.; Scherson, Daniel Alberto.

In: Russian Journal of Electrochemistry, Vol. 53, No. 9, 01.09.2017, p. 1003-1010.

Research output: Contribution to journalArticle

Feng, Zhange ; Georgescu, Nicholas S. ; Scherson, Daniel Alberto. / New advances in ohmic microscopy. In: Russian Journal of Electrochemistry. 2017 ; Vol. 53, No. 9. pp. 1003-1010.
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