Jiang Degang, Zhang Jizhen, Qin Si, Wang Zhiyu, Usman Ken Aldren S, Hegh Dylan, Liu Jingquan, Lei Weiwei, Razal Joselito M
Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.
College of Materials Science and Engineering, Institute for Graphene Applied Technology Innovation, Qingdao University, Ningxia Road 308, Qingdao 266071, China.
ACS Nano. 2021 Mar 23;15(3):5000-5010. doi: 10.1021/acsnano.0c09959. Epub 2021 Feb 26.
Superelastic aerogels with excellent electrical conductivity, reversible compressibility, and high durability hold great potential for varied emerging applications, ranging from wearable electronics to multifunctional scaffolds. In the present work, superelastic MXene/reduced graphene oxide (rGO) aerogels are fabricated by mixing MXene and GO flakes, followed by a multistep reduction of GO, freeze-casting, and finally an annealing process. By optimizing both the composition and reducing conditions, the resultant aerogel shows a reversible compressive strain of 95%, surpassing all current reported values. The conducting MXene/rGO network provides fast electron transfer and stable structural integrity under compression/release cycles. When assembled into compressible supercapacitors, 97.2% of the capacitance was retained after 1000 compression/release cycles. Moreover, the high conductivity and porous structure also enabled the fabrication of a piezoresistive sensor with high sensitivity (0.28 kPa), wide detection range (up to 66.98 kPa), and ultralow detection limit (∼60 Pa). It is envisaged that the superelasticity of MXene/rGO aerogels offers a versatile platform for utilizing MXene-based materials in a wide array of applications including wearable electronics, electromagnetic interference shielding, and flexible energy storage devices.
具有优异导电性、可逆压缩性和高耐久性的超弹性气凝胶在从可穿戴电子设备到多功能支架等各种新兴应用中具有巨大潜力。在本工作中，通过将MXene和氧化石墨烯（GO）薄片混合，随后对GO进行多步还原、冷冻铸造，最后进行退火处理，制备出了超弹性MXene/还原氧化石墨烯（rGO）气凝胶。通过优化组成和还原条件，所得气凝胶显示出95%的可逆压缩应变，超过了目前所有报道的值。导电的MXene/rGO网络在压缩/释放循环下提供了快速的电子转移和稳定的结构完整性。当组装成可压缩超级电容器时，在1000次压缩/释放循环后仍保留了97.2%的电容。此外，高导电性和多孔结构还使得能够制造出具有高灵敏度（0.28 kPa）、宽检测范围（高达66.98 kPa）和超低检测限（约60 Pa）的压阻传感器。可以设想，MXene/rGO气凝胶的超弹性为在包括可穿戴电子设备、电磁干扰屏蔽和柔性储能设备等广泛应用中利用基于MXene的材料提供了一个通用平台。
