1
|
Li C, Chen Q, Zheng R, Huan J, Bai J, Zhu L, Huang Y, Zhu X, Sun Y. Regulation of Sulfur Atoms in MoS x by Magneto-Electrodeposition for Hydrogen Evolution Reaction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2308729. [PMID: 38078778 DOI: 10.1002/smll.202308729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/22/2023] [Indexed: 05/25/2024]
Abstract
Compared with crystalline molybdenum sulfide (MoS2) employed as an efficient hydrogen evolution reaction (HER) catalyst, amorphous MoSx exhibits better activity. To synthesize amorphous MoSx, electrodeposition serving as a convenient and time-saving method is successfully applied. However, the loading mass is hindered by limited mass transfer efficiency and the available active sites require further improvement. Herein, magneto-electrodeposition is developed to synthesize MoSx with magnetic fields up to 9 T to investigate the effects of a magnetic field in the electrodeposition processing, as well as the induced electrochemical performance. Owing to the magneto-hydrodynamic effect, the loading mass of MoSx is obviously increased, and the terminal S2- serving as the active site is enhanced. The optimized MoSx catalyst delivers outstanding HER performance, achieving an overpotential of 50 mV at a current density of 10 mA cm-2 and the corresponding Tafel slope of 59 mV dec-1. The introduction of a magnetic field during the electrodeposition process will provide a novel route to prepare amorphous MoSx with improved electrochemical performance.
Collapse
Affiliation(s)
- Changdian Li
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Qian Chen
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Ruobing Zheng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Jie Huan
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- Science Island Branch of Graduate School, University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Jin Bai
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
| | - Lili Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
| | - Yanan Huang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
| | - Xuebin Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
| |
Collapse
|
2
|
Miura M, Sugiyama A, Oshikiri Y, Morimoto R, Mogi I, Miura M, Yamauchi Y, Aogaki R. Excess heat production of the pair annihilation of ionic vacancies in a copper redox reaction using a double bipolar MHD electrode. Sci Rep 2024; 14:1424. [PMID: 38228645 PMCID: PMC10792075 DOI: 10.1038/s41598-024-51834-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 01/10/2024] [Indexed: 01/18/2024] Open
Abstract
Through a copper double bipolar magnetohydrodynamic (MHD) electrode (MHDE) producing twice the amounts of ionic vacancies than a conventional single MHDE, the molar excess heat of the pair annihilation of ionic vacancies, 702 kJ mol-1 at 10 T on average was obtained in a copper redox reaction. It was about twice as large as that of a single MHDE, 387 kJ mol-1 at the same magnetic field. This result strongly suggests that a multi-channel bipolar MHDE will produce much greater excess heat. To conserve the linear momentum and electric charge during electron transfer in an electrode reaction, ionic vacancies are created, storing the solvation energy in the polarized core of the order of 0.1 nm, and the pair annihilation of the vacancies with opposite charges liberates the energy as excess heat. The promoted excess heat by the double bipolar MHDE with a diffuser at 10 T was 710 ± 144 kJ mol-1, whereas as mentioned above, 702 ± 426 kJ mol-1 was obtained by the same electrode without such a diffuser. From the theoretical excess heat of 1140 kJ mol-1, the collision efficiencies in pair annihilation were 0.623 ± 0.126 and 0.616 ± 0.374, respectively. From these results, the reproducibility of the thermal measurement was experimentally validated. At the same time, it was concluded that at magnetic fields beyond 10 T, the concentration of ionic vacancy and the collision efficiency take constant uppermost values.
Collapse
Affiliation(s)
- Makoto Miura
- Tohoku Polytechnic College, Kurihara, Miyagi, 987-2223, Japan.
| | | | - Yoshinobu Oshikiri
- Yamagata College of Industry and Technology, Matsuei, Yamagata, 990-2473, Japan
| | - Ryoichi Morimoto
- Saitama Industrial Technology Center, Kawaguchi, Saitama, 333-0844, Japan
| | - Iwao Mogi
- Institute for Materials Research, Tohoku University, Aoba-ku, Sendai, 980-8577, Japan
| | - Miki Miura
- Polytechnic Center Kimitsu, Kimitsu, Chiba, 299-1142, Japan
| | - Yusuke Yamauchi
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, 4072, Australia.
- Department of Materials Process Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan.
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea.
| | | |
Collapse
|
3
|
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.
Collapse
|
4
|
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]
|
5
|
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]
|
6
|
Li H, Lin S, Li H, Wu Z, Chen Q, Zhu L, Li C, Zhu X, Sun Y. Magneto-Electrodeposition of 3D Cross-Linked NiCo-LDH for Flexible High-Performance Supercapacitors. SMALL METHODS 2022; 6:e2101320. [PMID: 35032157 DOI: 10.1002/smtd.202101320] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/09/2021] [Indexed: 06/14/2023]
Abstract
Layered double hydroxides (LDHs) with outstanding redox activity on flexible current collectors can serve as ideal cathode materials for flexible hybrid supercapacitors in wearable energy storage devices. Electrodeposition is a facile, time-saving, and economical technique to fabricate LDHs. The limited loading mass induced by insufficient mass transport and finite exposure of active sites, however, greatly hinders the improvement of areal capacity. Herein, magneto-electrodeposition (MED) under high magnetic fields up to 9 T is developed to fabricate NiCo-LDH on flexible carbon cloth (CC) as well as Ti3 C2 Tx functionalized CC. Owing to the magneto-hydrodynamic effect induced by magnetic-electric field coupling, the loading mass and exposure of active sites are significantly increased. Moreover, a 3D cross-linked nest-like microstructure is constructed. The MED-derived NiCo-LDH delivers an ultrahigh areal capacity of 3.12 C cm-2 at 1 mA cm-2 and as-fabricated flexible hybrid supercapacitors show an excellent energy density with an outstanding cycling stability. This work provides a novel route to improve electrochemical performances of layered materials through MED technique.
Collapse
Affiliation(s)
- Hui Li
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Shuai Lin
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
| | - Han Li
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Ziqiang Wu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Qian Chen
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Lili Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Changdian Li
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- University of Science and Technology of China, Hefei, 230026, P. R. China
| | - Xuebin Zhu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
| | - Yuping Sun
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, P. R. China
| |
Collapse
|
7
|
Morimoto R, Miura M, Sugiyama A, Miura M, Oshikiri Y, Kim Y, Mogi I, Takagi S, Yamauchi Y, Aogaki R. Long-Term Electrodeposition under a Uniform Parallel Magnetic Field. 2. Flow-Mode Transition from Laminar MHD Flow to Convection Cells with Two-Dimensional (2D) Nucleation. J Phys Chem B 2020; 124:11870-11881. [PMID: 33347294 DOI: 10.1021/acs.jpcb.0c05905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Following the analysis of the self-organization of two-dimensional (2D) nuclei in Part 1, the flow-mode transition from laminar magnetohydrodynamics (MHD) flow to convection cells accompanied by 2D nucleation under a uniform parallel magnetic field was theoretically examined using the statistical mechanics of nonequilibrium fluctuation. As a result, it was clarified that secondary nodules of 2D nuclei develop with multiple nucleations during the transition, forming a one-upon-another structure. Then, the evolution of the convection cells as well as the secondary nodules requires unstable growth of the asymmetrical fluctuations by the specific adsorption of an ion. As predicted by the theory, the electrolytic current in copper deposition with specific adsorption of hydrogen ions under a parallel magnetic field developed with time, resulting in a nonlinear steplike curve in a 1200 s deposition time.
Collapse
Affiliation(s)
- Ryoichi Morimoto
- Saitama Industrial Technology Center, Kawaguchi, Saitama 333-0844, Japan
| | - Miki Miura
- Polytechnic Center Kimitsu, Kimitsu, Chiba 299-1142, Japan
| | - Atsushi Sugiyama
- Yoshino Denka Kogyo, Inc., Yoshikawa, Saitama 342-0008, Japan.,Research Organization for Nano and Life Innovation, Waseda University, Shinjuku, Tokyo 162-0041, Japan.,JST-ERATO Yamauchi Materials Space-Tectonics and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | - Makoto Miura
- Hokkaido Polytechnic College, Otaru, Hokkaido 047-0292, Japan
| | - Yoshinobu Oshikiri
- Yamagata College of Industry and Technology, Matsuei, Yamagata 990-2473, Japan
| | - Yena Kim
- JST-ERATO Yamauchi Materials Space-Tectonics and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan
| | - Iwao Mogi
- Institute for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan
| | - Satoshi Takagi
- Koriyama Technical Academy, Koriyama, Fukushima 963-8816, Japan
| | - Yusuke Yamauchi
- JST-ERATO Yamauchi Materials Space-Tectonics and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan.,School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, Queensland 4072, Australia.,Department of Plant & Environmental New Resources, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, South Korea
| | - Ryoichi Aogaki
- JST-ERATO Yamauchi Materials Space-Tectonics and International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044, Japan.,Polytechnic University, Sumida, Tokyo 130-0026, Japan
| |
Collapse
|
8
|
Excess heat production in the redox couple reaction of ferricyanide and ferrocyanide. Sci Rep 2020; 10:20072. [PMID: 33208775 PMCID: PMC7674507 DOI: 10.1038/s41598-020-76611-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/26/2020] [Indexed: 11/30/2022] Open
Abstract
In order to establish the universality of the excess heat production in electrochemical reaction, under a high magnetic field, as one of the most fundamental electrochemical reactions, the case of ferricyanide-ferrocyanide redox reaction was examined, where ionic vacancies with ± 1 unit charge were collided by means of magnetohydrodynamic (MHD) flow. As a result, from the pair annihilation of the vacancies with opposite signs, beyond 7 T, excess heat production up to 25 kJ·mol−1 in average at 15 T was observed, which was attributed to the liberation of the solvation energy stored in a pair of the vacancy cores with a 0.32 nm radius, i.e., 112 kJ·mol−1. Difference between the observed and expected energies comes from the small collision efficiency of 0.22 due to small radius of the vacancy core. Ionic vacancy initially created as a by-product of electrode reaction is unstable in solution phase, stabilized by releasing solvation energy. Ionic vacancy utilizes the energy to enlarge the core and stores the energy in it. As a result, solvated ionic vacancy consists of a polarized free space of the enlarged core surrounded by oppositely charged ionic cloud. The accuracy and precision of the measured values were ascertained by in situ standard additive method.
Collapse
|
9
|
Miura M, Sugiyama A, Oshikiri Y, Morimoto R, Mogi I, Miura M, Takagi S, Kim J, Yamauchi Y, Aogaki R. Excess Heat Production by the Pair Annihilation of Ionic Vacancies in Copper Redox Reactions. Sci Rep 2019; 9:13695. [PMID: 31548656 PMCID: PMC6757050 DOI: 10.1038/s41598-019-49310-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 08/12/2019] [Indexed: 11/30/2022] Open
Abstract
In the pair annihilation of ionic vacancies with opposite charges, a drastic excess heat production up to 410 kJ mol−1 in average at 10 T (i. e., 1.5 times larger than the heat production by the combustion of H2, 285.8 kJ mol−1) was observed, which was then attributed to the emission of the solvation energy stored in 0.61 nm radius vacancies with two unit charges. Under a high magnetic field, using Lorentz force, we made ionic vacancies created in copper cathodic and anodic reactions collide with each other, and measured the reaction heat by their annihilation. Ionic vacancy is initially created as a byproduct in electrode reaction in keeping the conservation of linear momentum and electric charge during electron transfer. The unstable polarized particle is stabilized by solvation, and the solvation energy is stored in the free space of the order of 0.1 nm surrounded by oppositely charged ionic cloud. The collision of the ionic vacancies was carried out by circulation-type magnetohydrodynamic electrode (c-type MHDE) composed of a rectangular channel with a pair of copper electrodes and a narrow electrolysis cell.
Collapse
Affiliation(s)
- Makoto Miura
- Hokkaido Polytechnic College, Otaru, Hokkaido, 047-0292, Japan.
| | - Atsushi Sugiyama
- Yoshino Denka Kogyo, Inc., Yoshikawa, Saitama, 342-0008, Japan.,Research Organization for Nano and Life Innovation, Waseda University, Shinjuku, Tokyo, 162-0041, Japan.,International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan
| | - Yoshinobu Oshikiri
- Yamagata College of Industry and Technology, Matsuei, Yamagata, 990-2473, Japan
| | - Ryoichi Morimoto
- Saitama Industrial Technology Center, Kawaguchi, Saitama, 333-0844, Japan
| | - Iwao Mogi
- Institute for Materials Research, Tohoku University, Aoba, Sendai, 980-8577, Japan
| | - Miki Miura
- Polytechnic Center Kimitsu, Kimitsu, Chiba, 299-1142, Japan
| | - Satoshi Takagi
- Graduate School of Symbiotic Systems Science and Technology, Fukushima University, Fukushima, 960-1296, Japan
| | - Jeonghun Kim
- School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Yusuke Yamauchi
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan. .,School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, 4072, Australia.
| | - Ryoichi Aogaki
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0044, Japan. .,Polytechnic University, Sumida, Tokyo, 130-0026, Japan.
| |
Collapse
|
10
|
Theory of microscopic electrodeposition under a uniform parallel magnetic field - 1. Nonequilibrium fluctuations of magnetohydrodynamic (MHD) flow. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.113254] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
11
|
Morimoto R, Miura M, Sugiyama A, Miura M, Oshikiri Y, Mogi I, Takagi S, Yamauchi Y, Aogaki R. Theory of microscopic electrodeposition under a uniform parallel magnetic field - 2. Suppression of 3D nucleation by micro-MHD flow. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.113255] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
12
|
Miura M, Oshikiri Y, Sugiyama A, Morimoto R, Mogi I, Miura M, Takagi S, Yamauchi Y, Aogaki R. Magneto-Dendrite Effect: Copper Electrodeposition under High Magnetic Field. Sci Rep 2017; 7:45511. [PMID: 28374758 PMCID: PMC5379626 DOI: 10.1038/srep45511] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/27/2017] [Indexed: 11/09/2022] Open
Abstract
Ionic vacancy is a by-product in electrochemical reaction, composed of polarized free space of the order of 0.1 nm with a 1 s lifetime, and playing key roles in nano-electrochemical processes. However, its chemical nature has not yet been clarified. In copper electrodeposition under a high magnetic field of 15 T, using a new electrode system called cyclotron magnetohydrodynamic (MHD) electrode (CMHDE) composed of a pair of concentric cylindrical electrodes, we have found an extraordinary dendritic growth with a drastic positive potential shift from hydrogen-gas evolution potential. Dendritic deposition is characterized by the co-deposition of hydrogen molecule, but such a positive potential shift makes hydrogen-gas evolution impossible. However, in the high magnetic field, instead of flat deposit, remarkable dendritic growth emerged. By examining the chemical nature of ionic vacancy, it was concluded that ionic vacancy works on the dendrite formation with the extraordinary potential shift.
Collapse
Affiliation(s)
- Makoto Miura
- Hokkaido Polytechnic College, Otaru, Hokkaido 047-0292, Japan
| | - Yoshinobu Oshikiri
- Yamagata College of Industry and Technology, Matsuei, Yamagata 990-2473, Japan
| | - Atsushi Sugiyama
- Yoshino Denka Kogyo, Inc., Yoshikawa, Saitama 342-0008, Japan.,Research Organization for Nano and Life Innovation, Waseda University, Shinjuku, Tokyo 162-0041, Japan.,National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Ryoichi Morimoto
- Saitama Prefectural Showa Water Filtration Plant, Kasukabe, Saitama 344-0113, Japan
| | - Iwao Mogi
- Institute for Materials Research, Tohoku University, Aoba-ku, Sendai 980-8577, Japan
| | - Miki Miura
- Yokohama Harbor Polytechnic College, Naka, Yokohama 231-0811, Japan
| | - Satoshi Takagi
- Koriyama Technical Academy, Koriyama, Fukushima 963-8816, Japan
| | - Yusuke Yamauchi
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Ryoichi Aogaki
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan.,Polytechnic University, Sumida, Tokyo 130-0026, Japan
| |
Collapse
|
13
|
Origin of Nanobubbles Electrochemically Formed in a Magnetic Field: Ionic Vacancy Production in Electrode Reaction. Sci Rep 2016; 6:28927. [PMID: 27377532 PMCID: PMC4932504 DOI: 10.1038/srep28927] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 06/10/2016] [Indexed: 11/23/2022] Open
Abstract
As a process complementing conventional electrode reactions, ionic vacancy production in electrode reaction was theoretically examined; whether reaction is anodic or cathodic, based on the momentum conservation by Newton’s second law of motion, electron transfer necessarily leads to the emission of original embryo vacancies, and dielectric polarization endows to them the same electric charge as trans- ferred in the reaction. Then, the emitted embryo vacancies immediately receive the thermal relaxation of solution particles to develop steady-state vacancies. After the vacancy production, nanobubbles are created by the collision of the vacancies in a vertical magnetic field.
Collapse
|