Non-electrochemical Nanobubble Formation in Ferricyanide/Ferrocyanide Redox Reaction by the Cyclotron Effect under a High Magnetic Field

Abstract

From the observation of coalesced microbubbles arising from supersaturated nanobubbles in ferricyanide/ferrocyanide redox reaction, the first evidence of the conversion from ionic vacancies to nanobubbles has been obtained. Since ionic vacancies are created without any electron transfer, the microbubbles are evolved in a different way from ordinal electrochemical gas reactions.

Microbubble Formation from Ionic Vacancies in Copper Anodic Dissolution under a High Magnetic Field

“…Almost the same regression line corresponding to two free surfaces has been obtained in the case of ferricyanide-ferrocyanide redox reaction. 20 The experimental result obtained here completely denies that ionic vacancy is a relevant phenomenon with hydrated electron. Namely, hydrated electrons, even if possible, would arise from cathodic reactions, whereas the microbubbles observed evolve from copper anodic dissolution.…”

“…The validity of these electrodes has been proved by the preceding experiments. 11,12 Then, the microbubbles are in situ observed by optical microscope. To ensure the process mentioned above, the origin of the gas contained in the microbubbles is examined by the following blank Electrochemistry, 83 (7), 549-553 (2015) test; prior to experiment, all the gases including dissolved gases are removed from the electrode cell with vacuum pump, which makes nanobubble formation impossible and will prepare the electrode surface without microbubble evolution.…”

“…4,5 Recently, it has been found that in electrode reactions, absolutely different type of cavity, i.e., ionic vacancies are created. 7,8,11,12 An ionic vacancy is composed of water molecules and ions, which yield a charged vacuum space of about a 1 ¡ radius surrounded by an oppositely charged ionic cloud (Fig. 1).…”

Microbubble Formation from Ionic Vacancies in Copper Electrodeposition under a High Magnetic Field

“…Based on this fact, instead of ionic vacancies, the microbubbles originating from them have been optically first observed in ferricyanide-ferrocyanide redox reaction. 8 However, only from this result, we cannot conclude that ionic vacancies are always created in electrode reactions. To ascertain whether vacancy production is universal in electrode reactions, further experimental examination is required.…”

“…During the potential sweep, as shown in Fig. 6, the globules of microbubble Electrochemistry, 82 (8), 654-657 (2014) continuously emerged ascending from the electrode surface and faded from view after several clockwise circulations. Just after the experiment, the blank test was performed under the same electrochemical conditions at 8 T after evacuating the dissolved gases.…”