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Nitrogen Bubbles at Pt Nanoelectrodes in a Nonaqueous Medium: Oscillating Behavior and Geometry of Critical Nuclei.
Chen, Qianjin; Liu, Yuwen; Edwards, Martin A; Liu, Yulong; White, Henry S.
Afiliación
  • Chen Q; Key Lab of Science and Technology of Eco-Textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China.
  • Liu Y; College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
  • Edwards MA; Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States.
  • Liu Y; Key Lab of Science and Technology of Eco-Textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, China.
  • White HS; Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States.
Anal Chem ; 92(9): 6408-6414, 2020 05 05.
Article en En | MEDLINE | ID: mdl-32281788
Gas bubble evolution is present in many electrochemical and photoelectrochemical processes. We previously reported the formation of individual H2, N2, and O2 nanobubbles generated from electrocatalytic reduction of H+ and oxidation of N2H4 and H2O2, respectively, at Pt nanodisk electrodes in an aqueous solution. All the nanobubbles formed display a dynamic stationary state of a three-phase boundary with an invariant residual current. Here, we test the hypothesis that gas nanobubbles can also be electrogenerated in a nonaqueous medium. Interestingly, we found oscillating bubble behavior corresponding to nucleation, growth, and dissolution in dimethyl sulfoxide and methanol. One possible explanation of the oscillation mechanism is provided by the instable dynamic equilibrium between the gas influx due to supersaturation and outflux due to Laplace pressure. Furthermore, the critical gas concentrations for N2 nanobubble nucleation are estimated to be 148, 386, 200, and 16 times supersaturation and the contact angles of the critical nuclei to be 164°, 151°, 160°, and 174° in water, dimethyl sulfoxide, ethylene glycol, and methanol, respectively. This is the first report on electrochemical nucleation of gas bubbles in nonaqueous solvents. Our electrochemical gas bubble study based on a nanoelectrode platform has proven to be a prototypical example of single-entity electrochemistry.

Texto completo: 1 Colección: 01-internacional Banco de datos: MEDLINE Idioma: En Revista: Anal Chem Año: 2020 Tipo del documento: Article País de afiliación: China

Texto completo: 1 Colección: 01-internacional Banco de datos: MEDLINE Idioma: En Revista: Anal Chem Año: 2020 Tipo del documento: Article País de afiliación: China