Bamgbelu, L;
Holt, KB;
(2019)
In Situ Determination of pH at Nanostructured Carbon Electrodes Using IR Spectroscopy.
Materials
, 12
(24)
, Article 4044. 10.3390/ma12244044.
Preview |
Text
Holt_In Situ Determination of pH at Nanostructured Carbon Electrodes Using IR Spectroscopy_VoR.pdf - Published Version Download (1MB) | Preview |
Abstract
Changes in pH at electrode surfaces can occur when redox reactions involving the production or consumption of protons take place. Many redox reactions of biological or analytical importance are proton-coupled, resulting in localized interfacial pH changes as the reaction proceeds. Other important electrochemical reactions, such as hydrogen and oxygen evolution reactions, can likewise result in pH changes near the electrode. However, it is very difficult to measure pH changes located within around 100 µm of the electrode surface. This paper describes the use of in situ attenuated total reflectance (ATR) infrared (IR) spectroscopy to determine the pH of different solutions directly at the electrode interface, while a potential is applied. Changes in the distinctive IR bands of solution phosphate species are used as an indicator of pH change, given that the protonation state of the phosphate ions is pH-dependent. We found that the pH at the surface of an electrode modified with carbon nanotubes can increase from 4.5 to 11 during the hydrogen evolution reaction, even in buffered solutions. The local pH change accompanying the hydroquinone-quinone redox reaction is also determined.
| Type: | Article |
|---|---|
| Title: | In Situ Determination of pH at Nanostructured Carbon Electrodes Using IR Spectroscopy |
| Location: | Switzerland |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3390/ma12244044 |
| Publisher version: | https://doi.org/10.3390/ma12244044 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | IR spectroscopy, carbon nanotubes, electrode, interface, pH, phosphate, spectroelectrochemistry |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10088137 |
Archive Staff Only
 |
View Item |
