In-situ high-speed atomic force microscopy observation of dynamic nanobubbles during water electrolysis

Mashu Mita; Hisayoshi Matsushima; Mikito Ueda; Hiroshi Ito

doi:10.1016/j.jcis.2022.01.089

In-situ high-speed atomic force microscopy observation of dynamic nanobubbles during water electrolysis

J Colloid Interface Sci. 2022 May 15:614:389-395. doi: 10.1016/j.jcis.2022.01.089. Epub 2022 Jan 19.

Authors

Mashu Mita¹, Hisayoshi Matsushima², Mikito Ueda¹, Hiroshi Ito³

Affiliations

¹ Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Sapporo, Hokkaido 060-8628, Japan.
² Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Sapporo, Hokkaido 060-8628, Japan. Electronic address: matsushima@eng.hokudai.ac.jp.
³ National Institute of Advanced Industrial Science & Technology (AIST), 1-2-1 Namiki, Tsukuba, Ibaraki 3058564, Japan.

PMID: 35104709
DOI: 10.1016/j.jcis.2022.01.089

Abstract

The nanobubbles (NB) formed on a solid surface has been reported, although the stability in a solution is still discussed. The atomic force microscopy (AFM) has shown the unique shape of the flatted NB, however the dynamic behavior has not investigated yet. Recently, the high scanning speed AFM (HS-AFM) has been developed and applied to the several interfaces. Here, we present in-situ HS-AFM observation during water electrolysis. The hydrogen and oxygen NB evolution on highly oriented pyrolytic graphite (HOPG) electrode are studied. Our video data is the first time to demonstrate the NB nucleation and the growth. The processes are different between both gases. The hydrogen NB grows with active coalescence, while the oxygen one is smaller and irregularly moves on HOPG surface. Using this technique, we will be able to study the NB stability influence by some factors, such as the surface potential and electric capillarity.

Keywords: Bubbles; HS-AFM; Hydrogen; Nucleation; Oxygen; Supersaturation; Water electrolysis.