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Theory of Chiral Electrodeposition by Chiral Micro-Nano-Vortices under a Vertical Magnetic Field -1: 2D Nucleation by Micro-Vortices. MAGNETOCHEMISTRY 2022. [DOI: 10.3390/magnetochemistry8070071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Remarkable chiral activity is donated to a copper deposit surface by magneto-electrodeposition, whose exact mechanism has been clarified by the three-generation model. In copper deposition under a vertical magnetic field, a macroscopic tornado-like rotation called the vertical magnetohydrodynamic (MHD) flow (VMHDF) emerges on a disk electrode, inducing the precessional motions of various chiral microscopic MHD vortices: First, chiral two-dimensional (2D) nuclei develop on an electrode by micro-MHD vortices. Then, chiral three-dimensional (3D) nuclei grow on a chiral 2D nucleus by chiral nano-MHD vortices. Finally, chiral screw dislocations are created on a chiral 3D nucleus by chiral ultra-micro MHD vortices. These three processes constitute nesting boxes, leading to a limiting enantiomeric excess (ee) ratio of 0.125. This means that almost all chiral activity of copper electrodes made by this method cannot exceed 0.125. It also became obvious that chirality inversion by chloride additive arises from the change from unstable to stable nucleation by the specific adsorption of it.
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Takagi S, Asada T, Oshikiri Y, Miura M, Morimoto R, Sugiyama A, Mogi I, Aogaki R. Nanobubble formation from ionic vacancies in an electrode reaction on a fringed disk electrode under a uniform vertical magnetic field -2. Measurement of the angular velocity of a vertical magnetohydrodynamic (MHD) flow by the microbubbles originating from ionic vacancies. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Takagi S, Asada T, Oshikiri Y, Miura M, Morimoto R, Sugiyama A, Mogi I, Aogaki R. Nanobubble formation from ionic vacancies in an electrode reaction on a fringed disk electrode under a uniform vertical magnetic field -1. Formation process in a vertical magnetohydrodynamic (MHD) flow. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116291] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fritzsche B, Lei Z, Yang X, Eckert K. Localization of rare earth ions in an inhomogeneous magnetic field toward their magnetic separation. J RARE EARTH 2022. [DOI: 10.1016/j.jre.2022.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Oscillatory Copper Deposition on Conical Iron Electrodes in a Nonuniform Magnetic Field. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7040046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We report the effect of a magnetic field on the deposition of copper ions on a conically shaped iron probe. In our setup, the magnetic forces and buoyancy are the key factors influencing the electrolyte flow and the mass transfer. Without external current, a spontaneous reduction of copper on the iron cone occurs, known as electroless deposition. Mach–Zehnder and differential interferometry indicate a variation in the concentration of copper ions near the cone. After an initial transient of about 60 s, temporal oscillations in the copper concentration are found under the effect of a magnetic field. In galvanostatic conditions, a similar oscillatory behavior of the concentration of the electrolyte is observed. Numerical simulations show that the oscillations are caused by the magnetic gradient, Lorentz force, and buoyancy force counteracting one another, and the oscillation frequency is estimated analytically based on this mechanism. Furthermore, we present a study on the oscillation frequency for both electroless and galvanostatic conditions with different current densities. The results of this study may stimulate future research aimed at the local control of the deposition rate and the realization of miniaturized, regularly structured deposits using magnetic fields.
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Huang M, Eckert K, Mutschke G. Magnetic-field-assisted electrodeposition of metal to obtain conically structured ferromagnetic layers. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2020.137374] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Liu J, Fang X, Zhu C, Xing X, Cui G, Li Z. Fabrication of superhydrophobic coatings for corrosion protection by electrodeposition: A comprehensive review. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125498] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Copper electrodeposition under a weak magnetic field: effect on the texturing and properties of the deposits. J APPL ELECTROCHEM 2020. [DOI: 10.1007/s10800-020-01492-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Zhang Y, Yuan B, Li L, Wang C. Edge electrodeposition effect of cobalt under an external magnetic field. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114143] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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