【公開日：2024.07.25】【最終更新日：2024.05.24】
課題データ / Project Data
課題番号 / Project Issue Number
23NM5210
利用課題名 / Title
機能材料の探索および応用の研究
利用した実施機関 / Support Institute
物質・材料研究機構 / NIMS
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）マテリアルの高度循環のための技術/Advanced materials recycling technologies（副 / Sub）-
キーワード / Keywords
蓄電関連材料/ Materials for power storage,カーボン系材料/ Carbon related materials,電子顕微鏡/ Electronic microscope,資源代替技術/ Resource alternative technology
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
唐 捷
所属名 / Affiliation
物質・材料研究機構
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
Lin Shiqi
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
利用形態 / Support Type
（主 / Main）機器利用/Equipment Utilization（副 / Sub）,技術補助/Technical Assistance
利用した主な設備 / Equipment Used in This Project
NM-504：200kV電界放出形透過電子顕微鏡（JEM-2100F2）
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
The current research on the application of graphene in supercapacitors mainly focuses on the preparation of graphene material with large capacitance by tuning the synthetic parameters. Although the stability of supercapacitors is a key factor for their practical applications, to the best of our knowledge, there were very few studies on the relationship between the reduction process of GO and the stability of graphene supercapacitors. To address the abovementioned issues, this study aims to optimize the structure of the residual functional groups on graphene sheets by tuning the reduction parameters, thereby understanding the relationship between the residual functional groups and the stability of graphene supercapacitors, and improving the performance of graphene supercapacitors. Transmission electron microscopy (TEM) was used to measure the obtained graphene.
実験 / Experimental
Graphene was synthesized by chemical reduction of graphene oxide (GO) using hydrazine as the reducing agent. The samples obtained with different reduction times were denoted as rGO-t-1, rGO-t-2, rGOt-3, rGO-t-6, rGO-t-12, rGO-t-24, and rGO-t-48, respectively. TEM samples were prepared by dropping a few milliliters of the graphene dispersion onto holey carbon mesh grids. TEM images were observed by a JEOL 2100 TEM with LaB6 and Cold Field emitters respectively.
結果と考察 / Results and Discussion
The morphology of rGO synthesized with various reduction times was studied by transmission electron microscopy (TEM). Fig. 1 shows low magnification TEM images of rGO with reduction times of 1 h (rGO-t-1), 3 h (rGO-t-3), 6 h (rGO-t-6), 12 h (rGO-t-12), 24 h (rGO-t-24), and 48 h (rGO-t-48). These rGOs exhibit a folded structure, with wrinkles on its two-dimensional plane, and tend to fall on each other. Besides, with the increase of reduction time, the rGO sheets tend to aggregate together. Selected-area electron diffraction (SAED) was also carried out to evaluate the crystallinity of graphene, which was helpful to understand the removal of oxygen-containing functional groups. The disordered distribution of oxygenic functional groups on the surface of graphene caused the diffraction rings to be blurred and broad. The effective removal of oxygenic functional groups would restore the six-fold symmetry of graphene. When the reduction time is below 12 h, the diffraction rings corresponding to the (100) and (110) planes of graphene are blurred and broad, suggesting a heavy presence of residual oxygenic functional groups. When the reduction time is more than 12 h, the diffraction rings corresponding to the (100) and (110) planes of graphene can be observed clearly, indicating the effective removal of oxygenic functional groups. Moreover, the diffraction spots became bright and sharp from graphene after reduction for 24 h, which indicated a sufficient removal of oxygenic functional groups and the restoration of the sp2 bonding of graphitic carbon.
図・表・数式 / Figures, Tables and Equations
Fig. 1 Low magnification TEM images of rGO with reduction time of (a) 1 h; (b) 3 h; (c) 6 h; (d) 12 h; (e) 24 h; (f) 48 h. Insets are the corresponding selected-area electron diffraction (SAED) patterns. Diffraction rings in the SAED patterns indicate the Bragg reflections corresponding to the (100) and (110) planes of graphene.
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件