Wang Zhenjiang, Yang Xinli, Wang Gang, Yang Xiping, Qiao Longhao, Lu Mingxia
School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001, People's Republic of China.
J Chem Phys. 2024 Aug 21;161(7). doi: 10.1063/5.0219584.
Three-dimensional (3D) reduced graphene oxide (rGO)/Ti2CTx MXene hybrid aerogels were effectively prepared by a two-step method involving hydrothermal reaction and freeze-drying. The intimately coupled rGO/Ti2CTx hybrid aerogel combined high electrical conductivity, large interlayer spacing, and excellent mechanical stability of Ti2CTx, which not only effectively prevents the self-restacking of Ti2CTx nanosheets, exposes more active sites exposed, and improves the volume change during the charge/discharge process but also increases the accessibility of ions and promotes the rapid transfer of ions/electrons. As a result, rGO/Ti2CTx 17.5-2.5 as the working electrode of electric double layer capacitors delivers a large specific capacity (107.05 F g-1 at 0.5 A g-1 in a 1M Na2SO4 electrolyte), a high rate capability (maintains 30% of its initial capacitance at 10 A g-1, which is much better than rGO and Ti2CTx), and excellent long-term large-current cycle stability (the initial capacitance remains above 71.1% after 10 000 cycles at 1 A g-1). In addition to providing a high-performance electrode for supercapacitors, this study proposes an efficient and time-saving strategy for constructing 3D structures from 2D materials.
通过水热反应和冷冻干燥两步法有效地制备了三维（3D）还原氧化石墨烯（rGO）/Ti2CTx MXene杂化气凝胶。紧密耦合的rGO/Ti2CTx杂化气凝胶结合了高电导率、大层间距以及Ti2CTx优异的机械稳定性，这不仅有效地防止了Ti2CTx纳米片的自堆叠，暴露出更多的活性位点，改善了充放电过程中的体积变化，还增加了离子的可及性，促进了离子/电子的快速转移。因此，rGO/Ti2CTx 17.5-2.5作为双电层电容器的工作电极，具有较大的比容量（在1M Na2SO4电解液中，0.5 A g-1时为107.05 F g-1）、高倍率性能（在10 A g-1时保持其初始电容的30%，远优于rGO和Ti2CTx）以及优异的长期大电流循环稳定性（在1 A g-1下10000次循环后，初始电容仍保持在71.1%以上）。除了为超级电容器提供高性能电极外，本研究还提出了一种从二维材料构建三维结构的高效省时策略。
