Reducing Structural Defects and Oxygen-Containing Functional Groups in GO-Hybridized CNTs Aerogels: Simultaneously Improve the Electrical and Mechanical Properties To Enhance Pressure Sensitivity

Three-dimensional graphene oxide–carbon nanotube (GO–CNT, abbreviated as GCNT) aerogels can find wide applications in various fields. Especially, low-density GCNT aerogels featuring both high conductivity and superelasticity are essential requirements for the construction of highly sensitive pressure sensor. However, simultaneous improvement on the electrical and mechanical properties of low-density GCNT is still a great challenge owing to their disordered microstructure, severe structural defects and massive oxygen-containing functional groups. Here, a structurally ordered and less defective GCNT aerogel featuring both high conductivity and superelasticity has been fabricated through alkali induced self-assembly of GO liquid crystals (GO LCs) and CNTs. Our methodology relies on the double roles of KOH solution as dispersant for CNTs and an inducer for the self-assembly of GO LCs nanosheets. The less-defective CNTs acting as reinforcement material contributes to the robust structure networks, leading to the significantly improved conductivity (2.4 S m^–1) and elasticity (14.3 kPa) of GCNT. Benefiting from these outstanding properties of GCNT aerogels, the assembled pressure sensor exhibits an ultrahigh sensitivity of 1.22 kPa^–1, rapid response time of 28 ms and excellent cycling stability, which enables it as a high-performance sensing platform to monitor various human motions in real time.