Towards Reproducible Fabrication of Nanometre‐Sized Carbon Electrodes: Optimisation of Automated Nanoelectrode Fabrication by Means of Transmission Electron Microscopy

Abstract

The reproducible fabrication of nanometre-sized carbon electrodes poses great challenges. Especially, the field of single entity electrochemistry has strict requirements regarding the geometry of these electrochemical probes. Herein, an automated setup for the fabrication of carbon nanoelectrodes based on the pyrolysis of a propane/butane gas mixture within pulled quartz capillaries by means of a moving heating coil is presented. It is shown that mere electrochemical characterisation with conventional redox mediators does not allow for a reliable assessment of the electrode's geometry and quality. Therefore, highthroughput transmission electron microscopy is used in parallel to evaluate and optimise preparation parameters. Control of the latter gives access to three different electrode types: nanopipettes, nanosamplers and nanodisks.

Reduced‐Graphene‐Oxide‐Based Needle‐Type Field‐Effect Transistor for Dopamine Sensing

“…The first step is the fabrication of double‐barrel carbon nanoelectrodes (dbCNEs) using a laser‐pulled theta‐shaped double‐barrel quartz capillary, followed by pyrolysis of a butane/propane gas mixture in an argon counter flow. Formation of dbCNEs is possible using a recently described automated pyrolysis setup . However, dbCNEs often exhibit an overgrown carbon film short‐circuiting both carbon nanoelectrodes (Figure a) or slightly recessed carbon (Figure b).…”

Oxygen Evolution Electrocatalysis of a Single MOF‐Derived Composite Nanoparticle on the Tip of a Nanoelectrode

“…[17] Comparison of the powder X-ray diffraction (PXRD) spectra with as imulated XRD pattern of the sodalite-type ZIF-67 crystal structure confirms the structural identity and phase purity of the as-synthesized ZIF-67 nanocrystals ( Figure S1). Thec arbon nanoelectrodes (CNEs) were fabricated using an automated pyrolysis setup ( Figure S2), [18] by pyrolytic decomposition of ab utane/propane mixture inside pulled quartz capillaries.S canning electron microscopy (SEM) indicates that the orifice of the as-prepared nanoelectrodes ranges between 250 and 270 nm in diameter ( Figure S3). Thet ip of the CNE was further trimmed using af ocused ion beam (FIB) to expose as olid carbon disk, as envisaged for attachment and growth of the ZIF nuclei ( Figure S4).…”

Elektrokatalyse als Nexus für nachhaltige erneuerbare Energien – der gordische Knoten aus Aktivität, Stabilität und Selektivität

“…[27] Nanoelektrochemische Methoden ermçglichen die Isolierung und Untersuchung der elektrochemischen Eigenschaften einzelner Nanopartikel und haben damit Vorteile gegenüber Methoden, die aus der Untersuchung aggregierter Nanopartikelensembles Rückschlüsse auf das Verhalten von Nanopartikeln ziehen. Die Mçglichkeit, Elektroden in Nanodimensionen mit präziser Kontrolle ihrer Durchmesser herzustellen [28,29] und elektrochemische Untersuchungen an solchen Elektroden oder nach ihrer Modifikation mit einzelnen Nanopartikeln durchzuführen, erlaubt es, Phänomene auf der Nanoskala frei von Interferenzen zu beobachten, welche die Zuverlässigkeit der Daten von mit Katalysatorfilmen modifizierten Makroelektroden beeinträchtigen. [28,30,31]…”