Simultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum Nanoelectrode
A conical-shaped Pt nanoelectrode whose tip apex features an effective electrode area was fabricated and used as a probe for scanning electrochemical microscopy (SECM). Nanoelectrodes were prepared by electroplating Pt in porous pyrolyzed polydimethylsiloxane filled into the tip of a quartz nanopipe...
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The Electrochemical Society of Japan
2021-05-01
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doaj-f58888834a27465c8db7f025d0533a532021-09-02T04:50:05ZengThe Electrochemical Society of JapanElectrochemistry2186-24512021-05-0189332332710.5796/electrochemistry.21-00013electrochemistrySimultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum NanoelectrodeHiroshi YAMADA0Nobutaka YAMANAKA1Kenji YASUNAGA2Department of Applied Chemistry, National Defense AcademyDepartment of Applied Chemistry, National Defense AcademyDepartment of Applied Chemistry, National Defense AcademyA conical-shaped Pt nanoelectrode whose tip apex features an effective electrode area was fabricated and used as a probe for scanning electrochemical microscopy (SECM). Nanoelectrodes were prepared by electroplating Pt in porous pyrolyzed polydimethylsiloxane filled into the tip of a quartz nanopipette. The current–distance curves were obtained by acquiring raw (without a low-pass filter) and low-pass-filtered (10 Hz) current simultaneously while a tip approached a flat Pt substrate. The raw-current approach curve showed the transition from faradaic feedback current to electron tunneling between the tip of the probe and the substrate. Alternatively, in the low-pass-filtered approach curve, a faradaic current with an improved signal-to-noise ratio was obtained without a transient increase of the tunneling current. From scanning electron microscopy observations, voltammograms, approach-curve measurements, and digital simulations of the response of a nanoelectrode, we deduced that only the apex of the conical-shaped electrode exhibited electrochemical activity and acted as an effective electrode. The constant-distance SECM imaging of an Au-sputtered polycarbonate membrane with sub-micrometer pores and Pt nanoparticles deposited on a highly oriented pyrolytic graphite (HOPG) was successfully demonstrated using the tunneling-current-based standing approach mode.https://www.jstage.jst.go.jp/article/electrochemistry/89/3/89_21-00013/_pdf/-char/ensecmstmnanoelectrodenanoparticle |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Hiroshi YAMADA Nobutaka YAMANAKA Kenji YASUNAGA |
spellingShingle |
Hiroshi YAMADA Nobutaka YAMANAKA Kenji YASUNAGA Simultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum Nanoelectrode Electrochemistry secm stm nanoelectrode nanoparticle |
author_facet |
Hiroshi YAMADA Nobutaka YAMANAKA Kenji YASUNAGA |
author_sort |
Hiroshi YAMADA |
title |
Simultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum Nanoelectrode |
title_short |
Simultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum Nanoelectrode |
title_full |
Simultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum Nanoelectrode |
title_fullStr |
Simultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum Nanoelectrode |
title_full_unstemmed |
Simultaneous Observation of Faradaic and Tunneling Current at a Flat Surface Using Tunneling-Current-Based Constant-Distance Scanning Electrochemical Microscopy with a Platinum Nanoelectrode |
title_sort |
simultaneous observation of faradaic and tunneling current at a flat surface using tunneling-current-based constant-distance scanning electrochemical microscopy with a platinum nanoelectrode |
publisher |
The Electrochemical Society of Japan |
series |
Electrochemistry |
issn |
2186-2451 |
publishDate |
2021-05-01 |
description |
A conical-shaped Pt nanoelectrode whose tip apex features an effective electrode area was fabricated and used as a probe for scanning electrochemical microscopy (SECM). Nanoelectrodes were prepared by electroplating Pt in porous pyrolyzed polydimethylsiloxane filled into the tip of a quartz nanopipette. The current–distance curves were obtained by acquiring raw (without a low-pass filter) and low-pass-filtered (10 Hz) current simultaneously while a tip approached a flat Pt substrate. The raw-current approach curve showed the transition from faradaic feedback current to electron tunneling between the tip of the probe and the substrate. Alternatively, in the low-pass-filtered approach curve, a faradaic current with an improved signal-to-noise ratio was obtained without a transient increase of the tunneling current. From scanning electron microscopy observations, voltammograms, approach-curve measurements, and digital simulations of the response of a nanoelectrode, we deduced that only the apex of the conical-shaped electrode exhibited electrochemical activity and acted as an effective electrode. The constant-distance SECM imaging of an Au-sputtered polycarbonate membrane with sub-micrometer pores and Pt nanoparticles deposited on a highly oriented pyrolytic graphite (HOPG) was successfully demonstrated using the tunneling-current-based standing approach mode. |
topic |
secm stm nanoelectrode nanoparticle |
url |
https://www.jstage.jst.go.jp/article/electrochemistry/89/3/89_21-00013/_pdf/-char/en |
work_keys_str_mv |
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