Zhou Jun, Zheng Yuying, Chen Dongyang
College of Materials Science and Engineering, Fuzhou University, Fuzhou 350116, China.
Nanomaterials (Basel). 2022 Feb 12;12(4):620. doi: 10.3390/nano12040620.
The self-restacking of graphene nanosheets inevitably compromises the electrochemical performance of conventional graphene-based materials. Herein, to solve this problem, we prepared a new type of three-dimensional porous aerogel with partially unzipped multiwalled carbon nanotubes inserted into graphene nanosheets via a reduction-reaction-induced self-assembly process. In the resulting aerogels, the inner carbon nanotubes (CNTs) tightly attach to the unzipped outer graphene nanoribbons (GNRs), which bridge with the graphene nanosheets. These interconnections bring them excellent electrical contact; the CNTs act as spacers to prevent the restacking of adjacent graphene nanosheets, and the abundant interconnected pores in the aerogels provide large channels for charge transfer. Accordingly, the aerogels exhibit a specific capacitance of 348.4 Fg at a scan rate of 5 mVs, with capacitance retention remaining at 89.7% at a current density of 2 Ag after 5000 cycles. The results show that the aerogels are promising electrode materials for supercapacitor applications.
石墨烯纳米片的自堆叠不可避免地会损害传统石墨烯基材料的电化学性能。在此,为了解决这个问题,我们通过还原反应诱导的自组装过程制备了一种新型的三维多孔气凝胶,其中部分解链的多壁碳纳米管插入到石墨烯纳米片中。在所得气凝胶中,内部碳纳米管(CNT)紧密附着在解链的外部石墨烯纳米带(GNR)上,而这些纳米带与石墨烯纳米片相连。这些互连赋予它们优异的电接触;碳纳米管充当间隔物以防止相邻石墨烯纳米片的重新堆叠,并且气凝胶中丰富的互连孔隙为电荷转移提供了大通道。因此,该气凝胶在5 mV s的扫描速率下表现出348.4 F g的比电容,在5000次循环后,在2 A g的电流密度下电容保持率仍为89.7%。结果表明,该气凝胶是用于超级电容器应用的有前途的电极材料。