1
|
Sakane S, Miura T, Munakata K, Morikawa Y, Miwa S, Yamanaka R, Sugai T, Ayukawa A, Udono H, Tanaka H. Precise synthesis of copper selenide nanowires with tailored Cu vacancies through photo-induced reduction for thermoelectric applications. NANOSCALE ADVANCES 2024; 6:3299-3305. [PMID: 38933852 PMCID: PMC11197438 DOI: 10.1039/d4na00156g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Accepted: 04/24/2024] [Indexed: 06/28/2024]
Abstract
Nanostructuring in α-Cu2Se while optimizing carrier concentration holds the promise of realizing further high thermoelectric performance at near room temperature. Nevertheless, controlling the amounts of Cu vacancies, which work as acceptors, in nanostructures is considerably more intricate than in bulk materials. Hence, controlling the amounts of Cu vacancies while maintaining the α-phase and nanostructure shape poses a formidable challenge. In this study, we synthesized Cu2+x Se nanowires (NWs) with various amounts of Cu vacancies at room temperature by the photoreduction method and investigated their thermoelectric properties. Cu2+x Se NWs exhibited a comparable thermoelectric power factor to that of the polycrystalline films fabricated at higher temperature. The achievement of the high power factor despite low-temperature fabrication is attributed to the precise synthesis of Cu2+x Se NWs with various amounts of Cu vacancies. We also investigated the reaction process of Cu2.00Se NWs in detail by observing the reaction intermediates. It was found that photoreduction occurred with Cu2+ ions adsorbed on Se NWs, leading to the reaction of Cu2+ ions and Se NWs without Cu deficiency. Namely, this photoreduction under the adsorbed conditions realized the control of Cu vacancies in Cu2+x Se NWs.
Collapse
Affiliation(s)
- Shunya Sakane
- Graduate School of Science and Engineering, Ibaraki University 4-12-1, Nakanarusawa-cho Hitachi Ibaraki 316-8511 Japan
| | - Tatsuki Miura
- Faculty of Science and Engineering, Chuo University 1-13-27, Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Kazuki Munakata
- Faculty of Science and Engineering, Chuo University 1-13-27, Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Yusuke Morikawa
- Faculty of Science and Engineering, Chuo University 1-13-27, Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Shunichiro Miwa
- Faculty of Science and Engineering, Chuo University 1-13-27, Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Riku Yamanaka
- Faculty of Science, Toho University 2-2-1, Miyama Funabashi-shi Chiba 274-8510 Japan
| | - Toshiki Sugai
- Faculty of Science, Toho University 2-2-1, Miyama Funabashi-shi Chiba 274-8510 Japan
| | - Akito Ayukawa
- Graduate School of Science and Engineering, Ibaraki University 4-12-1, Nakanarusawa-cho Hitachi Ibaraki 316-8511 Japan
| | - Haruhiko Udono
- Graduate School of Science and Engineering, Ibaraki University 4-12-1, Nakanarusawa-cho Hitachi Ibaraki 316-8511 Japan
| | - Hideki Tanaka
- Faculty of Science and Engineering, Chuo University 1-13-27, Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| |
Collapse
|
2
|
Sakane S, Akimoto K, Konishi K, Takaoka K, Iwatsuki H, Akutsu M, Sugai T, Tanaka H. Catalytic Activity of Nonaggregating Cu Nanoparticles Supported in Pores of Zeolite for Aerobic Oxidation of Benzyl Alcohol. ACS OMEGA 2024; 9:970-976. [PMID: 38222533 PMCID: PMC10785088 DOI: 10.1021/acsomega.3c07156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 01/16/2024]
Abstract
Cu nanoparticles (NPs) as catalysts have the good advantage of being more abundant than noble metal NPs. In this study, we synthesized nonaggregating Cu NPs supported in Y-type zeolite by the photoreduction method. In this method, Cu ions in pores of zeolite can be slowly reduced with a small amount of reductant at room temperature. The high-resolution transmission electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction patterns, and UV-Vis spectra supported that nonaggregating Cu NPs existed in the pores of zeolite. Catalytic activities of Cu NP-zeolite were investigated for the aerobic oxidation of benzyl alcohol. Our Cu NP-zeolite had a large turnover frequency of 17 h-1. The yield of benzaldehyde increased in proportion to the amount of Cu loading at ≤0.5 wt %, indicating that Cu NPs in pores of zeolite work as catalysts for selective aerobic oxidation of benzyl alcohol. The high catalytic activity was brought by nonaggregating Cu NPs in pores of zeolite. The catalytic reaction for other aromatic alcohols with electron-donating groups proceeded, whereas it did not proceed for the aromatic alcohols with electron-withdrawing groups or aliphatic alcohols, indicating that the interaction between zeolite and the benzene ring also contributed to the reaction. This study would be expected to contribute to the development of Cu NP catalysts.
Collapse
Affiliation(s)
- Shunya Sakane
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Kai Akimoto
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Kishin Konishi
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Kenta Takaoka
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Harunobu Iwatsuki
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Mayu Akutsu
- Department
of Chemistry, Faculty of Science, Toho University, 2-2-1, Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Toshiki Sugai
- Department
of Chemistry, Faculty of Science, Toho University, 2-2-1, Miyama, Funabashi-shi, Chiba 274-8510, Japan
| | - Hideki Tanaka
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| |
Collapse
|
3
|
Sakane S, Miwa S, Miura T, Munakata K, Ishibe T, Nakamura Y, Tanaka H. Thermoelectric Properties of PEDOT:PSS Containing Connected Copper Selenide Nanowires Synthesized by the Photoreduction Method. ACS OMEGA 2022; 7:32101-32107. [PMID: 36120067 PMCID: PMC9476199 DOI: 10.1021/acsomega.2c03335] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/25/2022] [Indexed: 06/15/2023]
Abstract
Organic materials have attracted attention for thermoelectric materials reusing low-temperature waste heat. For the thermoelectric performance enhancement of organic materials, the introduction of inorganic nanowires is effective due to the percolation effect. In this study, we synthesized Cu2Se NWs by the photoreduction method and prepared poly(3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) thin films containing Cu2Se NWs by spin-coating PEDOT:PSS and Cu2Se NWs alternatively. The composite films exhibited a drastic increase in electrical conductivity at more than 40 wt % Cu2Se, and the Cu2Se amount threshold was in good agreement with surface structures as observed by a scanning electron microscope. This indicates that the percolation effect of connected Cu2Se NWs brought high electrical conductivity. As a result, the composite thin films exhibited a higher power factor than the PEDOT:PSS film. This power factor enhancement by the percolation effect would be expected to contribute to the development of thermoelectric performance enhancement for organic materials.
Collapse
Affiliation(s)
- Shunya Sakane
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Shunichiro Miwa
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Tatsuki Miura
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Kazuki Munakata
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| | - Takafumi Ishibe
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
| | - Yoshiaki Nakamura
- Graduate
School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
| | - Hideki Tanaka
- Department
of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27, Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
| |
Collapse
|
4
|
Fujii K, Kurashima K, Hashizume H, Shimomura S, Wakahara T, Ando T. Study of Growing Ni Nanoparticles Loaded on Layered Inorganic-Imidazoline Covalently Bonded Hybrids Under a Transmission Electron Microscope. J Inorg Organomet Polym Mater 2021. [DOI: 10.1007/s10904-020-01753-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|