Controllable generation of interfacial gas structures on the graphite surface by substrate hydrophobicity and gas oversaturation in water

Fang, Hengxin; Geng, Zhanli; Guan, Nan; Zhou, Limin; Zhang, Lijuan; Hu, Jun

doi:10.1039/d2sm00849a

Cited by 8 publications

(9 citation statements)

References 75 publications

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“…On the other hand, water immersion appears to protect the surface of freshly stripped basal plane HOPG from “aging”. Our finding, in accordance with Li et al, confirms the widely accepted concept that the contamination is solely airborne, while Hu et al claimed that aging proceeds in water as well.…”

Section: Resultssupporting

confidence: 93%

“…Nanobubble incidence was found to rise significantly with prolonged surface exposure to an ambient atmosphere (aging) as illustrated by the AFM images of surfaces aged for 2, 23, and 96 h (Figure ). A similar trend was observed by Hu et al, explained by changes of the nanobubble nucleation rate on the hydrophobic surface.…”

Section: Resultssupporting

confidence: 88%

“…This finding, in accordance with the literature 26,39 reporting the appearance of gaseous nanodomains in partially degassed water, supports the incomplete The remarkable difference between the AFM images of the dry aged HOPG surface and after its immersion in water can be explained by the modification of the basal plane surface by airborne contaminants, forming an ultrathin subnanometer film, which is hardly recognizable by ex situ AFM. 30 Its immersion in water leads to trapping of ambient gas on hydrophobized (aged) HOPG creating gaseous nanodomains with dimensions significantly exceeding the nanometer scale and thus easily visualized by in situ AFM imaging. Prolonged aging of the HOPG surface by exposure to an ambient atmosphere (air) causes an increase in nanobubble population on the water-immersed HOPG surface, as summarized by statistic plots in Figure 5A, B.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Though gaseous composition of nanobubbles may influence their shape by pinning and contact angle as reported, e.g., Hu et al, pure atmospheric gases themselves are not responsible for the contamination effect. While numerous studies − report on gaseous nanodomains residing on a water-immersed HOPG surface, papers correlating their incidence with surface aging are scarce …”

Section: Introductionmentioning

confidence: 99%

“…While numerous studies 21−29 report on gaseous nanodomains residing on a water-immersed HOPG surface, papers correlating their incidence with surface aging are scarce. 30 This paper investigates the relation between aging of basal plane HOPG exposed to an ambient atmosphere and the existence of surface gaseous nanodomains explained by incomplete wetting.…”

Section: ■ Introductionmentioning

confidence: 99%

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Effect of Graphite Aging on Its Wetting Properties and Surface Blocking by Gaseous Nanodomains

Tarábková,

Janda

2023

Langmuir

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Early works considered basal planes of highly ordered pyrolytic graphite (HOPG) as hydrophobic, relatively inert materials with low electrocatalytic activity due to nonpolar sp 2 carbon. On the contrary, a freshly prepared HOPG surface exhibits intrinsically mildly hydrophilic properties, with a low contact angle of water, which increases after exposure to an ambient atmosphere. This process, called aging, ascribed to adsorption of airborne hydrocarbons, is reportedly accompanied by strong decay of electron transfer kinetics, the mechanism of which is not yet fully understood. Examining both freshly prepared and aged basal plane HOPG immersed in water by PeakForce quantitative nanomechanical imaging, we have found that aged HOPG is occupied by ambient gaseous nanodomains, the existence of which is explained by incomplete wetting. They cover up to 60% of the immersed surface and their incidence is in direct relation with graphite aging time. In contrast with aged graphite, gaseous nanodomains were absent on the freshly stripped HOPG surface. It can be concluded that ambient gaseous nanodomains can prevent aged basal plane HOPG from contact with aqueous media and may thus affect processes at the solid−liquid interface.

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Section: Resultssupporting

confidence: 93%

Section: Resultssupporting

confidence: 88%