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Zhang Y, Mei HX, Gao HL, Huo QY, Jia XD, Cao Y, Wang SW, Yan J, Luo HW, Yang J, Zhang AQ, Gao KZ. Metal oxide modified (NH4)(Ni,Co)PO4·0.67H2O composite as high-performance electrode materials for supercapacitors. INORG CHEM COMMUN 2020. [DOI: 10.1016/j.inoche.2019.107696] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Han H, Noh S, Chae S, Kim S, Choi Y, Le TH, Chang M, Kim H, Yoon H. Pine cone mold: a toolbox for fabricating unique metal/carbon nanohybrid electrocatalysts. NANOSCALE 2019; 11:23241-23250. [PMID: 31782466 DOI: 10.1039/c9nr06794a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nature presents delicate and complex materials systems beyond those fathomable by humans, and therefore, extensive effort has been made to utilize or mimic bio-materials and bio-systems in various fields. Biomass, an inexhaustible natural materials source, can also present good opportunities for the development of unprecedented, advanced materials and processing systems. Herein, we demonstrate the use of pine cones as a biomass mold for creating new and useful metal/carbon nanohybrids (MCNHs). The inherent water-induced folding actuation of the cone scales allows the casting of an aqueous solution of a single metal precursor or a binary metal mixture into the cone mold by simply immersing the cone in the solution. The cone actively absorbs aqueous-phase metal precursors through the bract scales and the precursor ions introduced into the cone are anchored to the functional groups of the interior tissues of the cone. Subsequent heat treatment successfully led to the formation of unique MCNHs. Iron, manganese, and cobalt were employed as model metals, binary mixtures of which were also cast into the cone mold to create further versatile MCNHs. Nanoparticulate metals were formed on the carbon supports, where the size, size distribution, and crystallinity of the nanoparticles were highly dependent on the identity of the single-component precursor and the combination of precursors. Consequently, the electrochemical activity of the MCNHs also depended on which metal precursors were cast into the cone mold. The MCNH prepared from the mixture of iron and manganese precursors (MFeMnCNH) showed the best electrochemical activity. As model applications, MFeMnCNH was applied to electrode materials for electrochemical charge storage and the oxygen evolution reaction. An electrochemical capacitor cell based on the MFeMnCNH electrodes showed excellent performance with energy densities of 38.7-54.2 W h kg-1 at power densities of 16 000-160 kW kg-1. In addition, MFeMnCNH demonstrated a low overpotential of 464 mV and fast kinetics with a Tafel slope of 64.6 mV dec-1 as an electrocatalyst for the oxygen evolution reaction in 1.0 M KOH. These results substantiate that pine cones as a biomass mold show great promise for creating versatile MCNHs through further combination of various precursors.
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Affiliation(s)
- Hyunwoo Han
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea.
| | - Seonmyeong Noh
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea.
| | - Sunbin Chae
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea.
| | - Semin Kim
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea.
| | - Yunseok Choi
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea.
| | - Thanh-Hai Le
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea.
| | - Mincheol Chang
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea. and School of Polymer Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea
| | - Hyungwoo Kim
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea. and School of Polymer Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea
| | - Hyeonseok Yoon
- Department of Polymer Engineering, Graduate School, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea. and School of Polymer Science and Engineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwanju, 61186, South Korea
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Guo X, Zhang Q, Li Q, Yu H, Liu Y. Composite Aerogels of Carbon Nanocellulose Fibers and Mixed-Valent Manganese Oxides as Renewable Supercapacitor Electrodes. Polymers (Basel) 2019; 11:E129. [PMID: 30960113 PMCID: PMC6404137 DOI: 10.3390/polym11010129] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 01/02/2019] [Accepted: 01/03/2019] [Indexed: 11/16/2022] Open
Abstract
Bio-waste derived nanocelluloses show excellent mechanical flexibility and self-aggregated capability, which enable them to be good supporting substrates for the synthesis of electroactive materials. Herein, we present a facile route for fabricating composite aerogels consisting of carbonized nanocellulose fibers (CNF) and mixed-valent manganese oxide (MnOx), toward supercapacitor applications. Mixed solutions of nanocellulose and manganese acetate with different ratios were prepared and freeze-dried into hybrid aerogels. The hybrid aerogels were then transformed into CNF/MnOx composites by a calcination process. The CNF membranes served as porous carbon nano-reservoirs for MnOx and electrolyte. The CNF/MnOx composites also kept a 3D porous aerogel structure with hierarchical pores, which enabled stable transport of both electrolyte ions and electrons to the electrode surface, leading to low a charge-transfer impedance and good electrochemical kinetics. The CNF/MnOx-based symmetric supercapacitor showed a satisfied energy density and power density of 37.5 Wh kg-1 and 2.75 kW kg-1, respectively. All the above results demonstrate the feasibility of using sustainable nanocellulose as a nanoscale carbon substrate for the synthesis of hybrid composite electrodes toward renewable supercapacitor applications.
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Affiliation(s)
- Xiaoyu Guo
- Key Laboratory of Bio-Based Material Science and Technology, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
| | - Qi Zhang
- Key Laboratory of Bio-Based Material Science and Technology, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
| | - Qing Li
- Key Laboratory of Bio-Based Material Science and Technology, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
| | - Haipeng Yu
- Key Laboratory of Bio-Based Material Science and Technology, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
| | - Yixing Liu
- Key Laboratory of Bio-Based Material Science and Technology, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
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