High Resolution Deposition of Silver in Nafion Films with the Scanning Tunneling Microscope

Craston, Derek H.; Lin, Charles W.; Bard, Allen J.

doi:10.1149/1.2095752

Cited by 90 publications

(38 citation statements)

References 3 publications

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“…[138][139][140][141][142][143] Der Entwicklungsstand wurde mehrfach in Übersichtsartikeln dargelegt. [16,[144][145][146][147] Die SECM-Methode erlaubt chemisch vielfälti-ge und definierte Modifikationen von Oberflächen, die mit anderen Verfahren oft nicht zugänglich sind.…”

Section: Secm Als Mikrostrukturierungswerkzeugunclassified

Elektrochemische Rastermikroskopie zur direkten Abbildung von Reaktionsgeschwindigkeiten

Wittstock¹,

Burchardt²,

Pust³

et al. 2007

Angewandte Chemie

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Eine entscheidende Rolle in der Elektrochemie, aber auch in biologischen Systemen oder beim Transport durch Membranen, spielen lokale Prozesse an Fest‐flüssig‐Grenzflächen oder Flüssig‐flüssig‐Grenzflächen, die z. B. an Defektstellen, an Poren oder an einzelnen Zellen ablaufen und sich durch integrale Untersuchungsverfahren nur schwer erfassen lassen. Mit der elektrochemischen Rastermikroskopie steht eine Untersuchungsmethode für lokale Grenzflächenreaktionen zur Verfügung, die nach zwei Jahrzehnten Entwicklung eine solide theoretische Basis und eine große Zahl von Anwendungen aufweist. Sie bietet die Möglichkeit, Geschwindigkeiten heterogener Reaktionen direkt abzubilden und Oberflächen durch elektrochemisch erzeugte Reaktanten lokal zu modifizieren. Die Vielfalt der Anwendungen reicht von klassischen elektrochemischen Fragestellungen bei der Untersuchung lokaler Korrosionsphänomene und elektrokatalytischer Reaktionen in Brennstoffzellen, von Sensoroberflächen, Biochips und mikrostrukturierten Analysesystemen bis hin zum Massentransport durch synthetische Membranen, Haut und Gewebe sowie interzellulären Kommunikationsprozessen. Außerdem können Prozesse an Flüssigkeitsoberflächen oder an Flüssig‐flüssig‐Grenzflächen untersucht werden.

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Section: Secm Als Mikrostrukturierungswerkzeugunclassified

Elektrochemische Rastermikroskopie zur direkten Abbildung von Reaktionsgeschwindigkeiten

Wittstock¹,

Burchardt²,

Pust³

et al. 2007

Angewandte Chemie

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“…3 m. Also shown in Fig. 5 is the anodic background current that is the result of the oxidation of W [in the absence of Ru(NH 3 ) 6 3ϩ ] at potentials positive of Ϫ0.4 V vs. SCE (curve b). The anodic background current at this tip at ϩ0.5 V in this medium is about 1 nA.…”

Section: Surface Conductance Of Mica-the Effects Of Relative Humiditymentioning

confidence: 99%

“…In this case, very high resolution can be attained with a tip without insulation, because only the end of the tip is in contact with the liquid layer. A similar approach was previously used to fabricate small metal or conductive polymer structures in polymer films by carrying out EC deposition in air (6)(7)(8). Etching and imaging of highly ordered pyrolytic graphite at nanometer resolution was also achieved by this approach (9).…”

mentioning

confidence: 99%

Imaging of biological macromolecules on mica in humid air by scanning electrochemical microscopy

Fan

Bard

1999

Proc. Natl. Acad. Sci. U.S.A.

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111

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Imaging of DNA, keyhole limpet hemocyanin, mouse monoclonal IgG, and glucose oxidase on a mica substrate has been accomplished by scanning electrochemical microscopy with a tungsten tip. The technique requires the use of a high relative humidity to form a thin film of water on the mica surface that allows electrochemical reactions to take place at the tip and produce a faradaic current (Ϸ1 pA) that can be used to control tip position. The effect of relative humidity and surface pretreatment with buffer solutions on the ionic conductivity of a mica surface was investigated to find appropriate conditions for imaging. Resolution of the order of 1 nm was obtained.H igh-resolution imaging of nanostructured materials, especially soft and sensitive biological samples, poses a great challenge in material science and biology. The structures of individual biological molecules at nanometer-scale resolution have been traditionally studied by high-resolution electron microscopy and x-ray crystallography. However, these techniques often require difficult sample-preparation procedures and potentially damaging experimental conditions or depend on the availability of obtaining crystalline samples. The atomic-force microscope has been extensively used to image biological samples and is especially convenient because the molecules can be observed under ambient or physiological conditions. However, atomic-force microscopy does not provide chemical information, and special precautions are required to prevent the tip from damaging or altering the sample. In the family of scanning probe microscopes (1), the scanning electrochemical (EC) microscope (SECM) allows for both structural and chemical information of the surface (so-called chemical imaging). However, the application of SECM has largely focused on analytical investigations, e.g., in studies of interfacial kinetics, rather than as a highresolution imaging tool (2). In the amperometric mode, the SECM is similar to the better-known scanning tunneling microscope (STM), in that it measures the current flow through a conductive tip. However, it differs from the STM in that the current response is an EC one, and the sample is interrogated by solution species generated or reacting at the tip rather than by a strong interaction with the tip itself.The resolution attainable with a SECM is largely governed by the tip size and the distance between tip and sample. Most SECM measurements are carried out with the sample under a thick liquid layer; under these conditions, the tip must be sheathed in an insulator so that only the very end is exposed to solution to achieve high resolution. SECM measurements can also be carried out in ambient or humid air. When a substrate, like mica, with a hydrophilic surface is exposed to air, a thin layer of water forms on the surface. As shown by Guckenberger et al. (3), imaging is possible within this thin liquid layer. As we have discussed previously (4, 5), the current that passes between tip and contact is a faradaic one, based on EC reactions that take ...

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“…The UME current is balanced by i S that is of the same size and opposite direction. If i S can be confined to a small area close to the UME, local surface modification or analysis can be performed [120][121][122][123] (Figure 9). The confinement of the reaction is achieved by one of the following concepts: -The experiment is performed with a probe penetrating or touching a thin polymeric electrolyte [120,124].…”

Section: Direct Modementioning

confidence: 99%

“…If i S can be confined to a small area close to the UME, local surface modification or analysis can be performed [120][121][122][123] (Figure 9). The confinement of the reaction is achieved by one of the following concepts: -The experiment is performed with a probe penetrating or touching a thin polymeric electrolyte [120,124]. -Dynamic concentration changes of reagents in specifically designed pulse sequences are exploited [125,126].…”

Section: Direct Modementioning

confidence: 99%

Investigation of Localized Catalytic and Electrocatalytic Processes and Corrosion Reactions with Scanning Electrochemical Microscopy (SECM)

Pust¹,

Maier²,

Wittstock³

2008

Zeitschrift Für Physikalische Chemie

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Scanning Electrochemical Microscopy (SECM) . Catalytic Electrodes .Electrochemical Energy Conversion . Fuel Cells . Oxygen Reduction Reaction . CorrosionScanning electrochemical microscopy (SECM) has developed into a very versatile tool for the investigation of solid-liquid, liquid-liquid and liquid-gas interfaces. The arrangement of an ultramicroelectrode (UME) in close proximity to the interface under study allows the application of a large variety of different experimental schemes. The most important have been named feedback mode, generation-collection mode, redox competition mode and direct mode. Quantitative descriptions are available for the UME signal, depending on different sample properties and experimental variables. Therefore, SECM has been established as an indispensible tool in many areas of fundamental electrochemical research. Currently, it also spreads as an important new method to solve more applied problems, in which inhomogeneous current distributions are typically observed on different length scales. Prominent examples include devices for electrochemical energy conversion such as fuel cells and batteries as well as localized corrosion phenomena. However, the direct local investigation of such systems is often impossible. Instead, suitable reaction schemes, sample environments, model samples and even new operation modes have to be introduced in order to obtain results that are relevant to the practical application. This review outlines and compares the theoretical basis of the different SECM working modes and reviews the application in the area of electrochemical energy conversion and localized

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High Resolution Deposition of Silver in Nafion Films with the Scanning Tunneling Microscope

Abstract: not Available.

Cited by 90 publications

References 3 publications

Elektrochemische Rastermikroskopie zur direkten Abbildung von Reaktionsgeschwindigkeiten

Elektrochemische Rastermikroskopie zur direkten Abbildung von Reaktionsgeschwindigkeiten

Imaging of biological macromolecules on mica in humid air by scanning electrochemical microscopy

Investigation of Localized Catalytic and Electrocatalytic Processes and Corrosion Reactions with Scanning Electrochemical Microscopy (SECM)

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