Visualization and Quantification of Electrochemical H2 Bubble Nucleation at Pt, Au, and MoS2 Substrates

Electrolytic gas evolution is a significant phenomenon in many electrochemical technologies from water splitting, chloralkali process to fuel cells. Although it is known that gas evolution may substantially affect the ohmic resistance and mass transfer, studies focusing on the electrochemistry of in...

Full description

Saved in:
Bibliographic Details
Published in:ACS sensors 2021-02, Vol.6 (2), p.355-363
Main Authors: Liu, Yulong, Jin, Cheng, Liu, Yuwen, Ruiz, Karla Hernandez, Ren, Hang, Fan, Yuchi, White, Henry S, Chen, Qianjin
Format: Article
Language:English
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Electrolytic gas evolution is a significant phenomenon in many electrochemical technologies from water splitting, chloralkali process to fuel cells. Although it is known that gas evolution may substantially affect the ohmic resistance and mass transfer, studies focusing on the electrochemistry of individual bubbles are critical but also challenging. Here, we report an approach using scanning electrochemical cell microscopy (SECCM) with a single channel pipet to quantitatively study individual gas bubble nucleation on different electrode substrates, including conventional polycrystalline Pt and Au films, as well as the most interesting two-dimensional semiconductor MoS2. Due to the confinement effect of the pipet, well-defined peak-shaped voltammetric features associated with single bubble nucleation and growth are consistently observed. From stochastic bubble nucleation measurement and finite element simulation, the surface H2 concentration corresponding to bubble nucleation is estimated to be ∼218, 137, and 157 mM, with critical nuclei contact angles of ∼156°, ∼161°, and ∼160° at polycrystalline Pt, Au, and MoS2 substrates, respectively. We further demonstrated the surface faceting at polycrystalline Pt is not specifically correlated with the bubble nucleation behavior.
ISSN:2379-3694
2379-3694
DOI:10.1021/acssensors.0c00913