Ishii Yosuke, Ishigame Koki, Kido Yusuke, Kato Yuichiro, Yamamoto Kengo, Sagisaka Kento, Hattori Yoshiyuki, Al-Zubaidi Ayar, Kondo Kohei, Kawasaki Shinji
Department of Life Science and Applied Chemistry, Nagoya Institute of Technology Gokiso-cho, Showa-ku Nagoya 466-8555 Japan
Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University 3-15-1 Tokida Ueda 386-8567 Japan.
RSC Adv. 2019 Dec 18;9(72):42043-42049. doi: 10.1039/c9ra07546a.
Carbon fibers and sheets were prepared from jet-milled natural chitin and cellulose samples, and from natural lignin sample using ice-templating technique, respectively. Nitrogen doping treatments using melamine were also performed for the carbon fibers and sheets. Electric double layer capacitor (EDLC) electrode properties of the prepared carbon fibers and sheets including the nitrogen doped samples were investigated with aqueous (sulfuric acid) and organic (tetraethylammonium tetrafluoroborate in propylene carbonate) electrolytes. It was found that the nitrogen doped lignin carbon sheets having very small specific surface area of 66 m g show very high EDLC capacitances of 227 F g and 80 F g determined by charge-discharge measurements at current density of 50 mA g for aqueous and organic electrolytes, respectively. X-ray photoelectron spectroscopy (XPS) measurements revealed that nitrogen atoms of the nitrogen doped lignin carbon sheets exist dominantly in pyridinic sites unlike other chitin and cellulose carbon fibers. We discussed that this site-selective nitrogen doping gives exceptionally high ion adsorption density per unit surface area of the nitrogen doped lignin carbon sheets.
分别使用冰模板技术，由喷射研磨的天然几丁质和纤维素样品以及天然木质素样品制备了碳纤维和碳片。还对碳纤维和碳片进行了使用三聚氰胺的氮掺杂处理。使用水性（硫酸）和有机（碳酸丙烯酯中的四乙基四氟硼酸铵）电解质研究了所制备的碳纤维和碳片（包括氮掺杂样品）的双电层电容器（EDLC）电极性能。结果发现，具有66 m²/g非常小比表面积的氮掺杂木质素碳片，对于水性和有机电解质，在50 mA/g电流密度下通过充放电测量确定的EDLC电容分别非常高，为227 F/g和80 F/g。X射线光电子能谱（XPS）测量表明，与其他几丁质和纤维素碳纤维不同，氮掺杂木质素碳片的氮原子主要存在于吡啶型位点。我们讨论了这种位点选择性氮掺杂使氮掺杂木质素碳片的单位表面积具有异常高的离子吸附密度。
