Volume 9, Issue 18 e202200754
Research Article

Pt Nanoelectrodes Sealed in Quartz Capillaries Modified with Underpotential-Deposited Bismuth for Formic Acid Electrooxidation

Prof. Dr. Dario Battistel

Prof. Dr. Dario Battistel

University Ca' Foscari Venice, Department of Environmental Sciences, Informatics and Statistics, Via Torino 155, 30172 Mestre-Venezia, Italy

Contribution: Data curation (equal), Methodology (equal), Validation (equal)

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Dr. Alberto Citron

Dr. Alberto Citron

Department of Molecular Sciences and Nanosystems, University Cà Foscari Venice, Via Torino 155, 30172 Mestre-Venezia, Italy

Contribution: ​Investigation (equal)

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Dr. Daniele Veclani

Dr. Daniele Veclani

The Institute of Organic Synthesis and Photoreactivity (ISOF), Research Council of Italy (CNR), Area della Ricerca di Bologna, Via P. Gobetti 101, 40129 Bologna, Italy

Contribution: Data curation (equal)

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Salvatore Daniele

Corresponding Author

Salvatore Daniele

Department of Molecular Sciences and Nanosystems, University Cà Foscari Venice, Via Torino 155, 30172 Mestre-Venezia, Italy

Contribution: Conceptualization (lead), Supervision (lead), Validation (lead), Writing - original draft (lead)

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First published: 22 August 2022

Graphical Abstract

Enhancing real surface area: Pt disk nanoelectrodes, sealed in quartz capillaries by the laser-pulled assisted procedure, display in 0.5 M H2SO4 real surface areas extraordinarily larger than the corresponding geometric ones. This is due to diffusion of adsorbed species at the Pt/quartz interface along portions of the Pt wires sealed inside the glass. Although to a lesser extent, this phenomenon also occurs with under-potential deposited metallic bismuth. The Bi-loaded Pt nanoelectrodes are employed to probe the electrooxidation of HCOOH.

Abstract

Platinum disk nano- and micro-electrodes with radii in the range 40 nm–12.5 μm were fabricated using quartz capillaries and the laser-puller assisted approach. The hydrogen underpotential deposition (H-UPD), performed in a 0.5 M H2SO4 aqueous solution, revealed that the nanoelectrodes, with radii of 160 nm and less, displayed extraordinarily large surface areas, which in terms of roughness factors (RFs, i. e., the ratio of the real surface areas to the geometric surface areas) were in the range 1030–3600. This finding was attributed to diffusion of adsorbed species at the Pt/quartz interface along portions of the Pt wires sealed within the glass. RFs between 2 and 3 were instead found at the microelectrodes. Similar results were also obtained with underpotential-deposited metallic bismuth. In this case, diffusion of Bi adatoms onto the Pt surface was hindered to some extent, providing a RF value of 172. Bi-modified Pt nano- and micro-electrodes were employed to study the electrooxidation of HCOOH, which is of interest in the field of fuel cells. It was found that the nanoelectrode displayed higher activity towards the electrooxidation of HCOOH and tolerance to CO poisoning, compared to the microelectrode.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.