Zirconia/Carbon Fiber–Graphene Aerogel-Based Composites for Thermal Insulation and High-Fidelity Sensing

In this study, multifunctional aerogel composites with three-dimensional network structures were successfully constructed by a synergistic strategy of hydrothermal reduction–freeze-drying–high-temperature annealing. Zirconia-modified carbon fiber nanofibers (ZrO2/CF), methyltrimethoxysilane (MTMS), and MXene-reinforced graphene aerogel (ZrO2/CF-MMGA) were developed, and the composite system was constructed through the introduction of the ZrO2/CF nanofiber skeleton and MXene conductive network, which realized the synergistic optimization of the rigid-flexible structure and confirmed the cross-linked structure. The advantages of the composite system come from the multilayer structural design: the nanofiber backbone provides mechanical support, the MXene network optimizes charge transport, and the porous aerogel enhances the signal response through the stress-concentration effect, resulting in high sensitivity (14.8 kPa–1), ultralow density (20 mg·cm–3) and excellent electrical conductivity (12.3 S·cm–1), ultralow thermal conductivity (0.0225 W·m–1·K–1), and fast response (48 ms response/40 ms relaxation), showing great potential in wearable and spatial pressure distribution sensor fields. This study presents an innovative paradigm for designing multiscale structures to develop, flexible electronic devices.