Graphene‐based aerogels have been widely studied for their high porosity, good compressibility, and electrical conductivity as piezoresistive sensors. However, the fabrication of graphene aerogel sensors with good mechanical properties and excellent sensing properties simultaneously remains a challenge. Therefore, in this study, a novel nanofiber reinforced graphene aerogel (aPANF/GA) which has a 3D interconnected hierarchical microstructure with surface‐treated PAN nanofiber as a support scaffold throughout the entire graphene network is designed. This 3D interconnected microporous aPANF/GA aerogel combines an excellent compressive stress of 43.50 kPa and a high piezoresistive sensitivity of 28.62 kPa−1 as well as a wide range (0–14 kPa) linear sensitivity. When aPANF/GA is used as a piezoresistive sensor, the compression resilience is excellent, the response time is fast at about 37 ms at 3 Pa, and the structural stability and sensing durability are good after 2600 cycles. Indeed, the current signal value is 91.57% of the initial signal value at 20% compressive strain. Furthermore, the assembled sensors can monitor the real time movement of throat, wrist pulse, fingers, wrist, and knee joints of the human body at good sensitivity. These excellent features enable potential applications in health detection.

Nanofibers with unique structures and multiple components have attracted more and more attention, which could combine multi-functions in one entity. Janus-type biphasic nanofibers with unique structure can be quickly obtained by electrospinning technology. We produced CoO x /C nanofibers with Janus structure by self-made side-by-side electrospinning spinneret, combined with electrospinning technology and heat treatment. CoO x /C nanofibers had a large amount of graphitic carbon distributed on one half of the Janus nanofiber, and CoO x /C nanoparticles were embedded in the other half of the Janus nanofiber and distributed uniformly. CoO x /C acted as ORR catalysis, and graphitic carbon, pridinc-N and CoO x in CoO x /C had a synergistic effect on their catalytic activity. The results confirmed that CoO x /C was dominated by four-electron pathway under alkaline conditions, and the Tafel slope was lower than that of commercial Pt/C catalysts. The preparation method of this work is simple and easy, the structure is controllable, and the composition is adjustable, which provides a feasible way for preparing Janus structure nanofibers with different functions.

Moisture actuators can accomplish humidity-triggered energy-conversion process, through material screening and structural design. Inspired by natural caterpillars and the hydrophilic properties of graphene oxide (GO), this work proposes a geometrical design of period-gradient structures in GO films for fabricating moisture actuators. These novel period-gradient-structured GO films exhibit excellent dynamic performance that they could deform at 1000° with a small radius in several seconds at a high relative humidity (RH ≈ 80%). The properties of fast actuating speed and high response to deformation are achieved through the structural designing of the sole GO film by a one-step formation process. A mechanics-based theoretical model combined with the finite element simulation is presented to demonstrate the actuating mechanism in geometry, moisture, and mechanics, which lays the foundation for potential applications of GO films in remote control, environmental monitoring, and man–machine interactions.

Carbon-based non-precious metal catalysts have been regarded as the most promising alternatives to the state-of-art Pt/C catalyst for the oxygen reduction reaction (ORR). However, there are still some unresolved challenges such as agglomeration of nanoparticles, complex preparation process and low production efficiency, which severely hamper the large-scale production of non-precious metal catalysts. Herein, a novel carbon-based non-precious metal catalyst, i.e. iron carbide nanoparticles embedded on carbon nanofibers (Fe 2 C/CNFs), prepared via the direct pyrolysis of carbon-and iron-containing Janus fibrous precursors obtained by electrospinning. The Fe 2 C/CNF catalyst shows uniform dispersion and narrow size distribution of Fe 2 C nanoparticles embedded on the CNFs. The obtained catalyst exhibits positive onset potential (0.87 V versus RHE), large kinetic current density (1.9 mA cm −2 ), and nearly follows the effective four-electron route, suggesting an outstanding electrocatalytic activity for the ORR in 0.1 M of KOH solution. Besides, its stability is better than that of the commercial Pt/C catalyst, due to the strong binding force between Fe 2 C particles and CNFs. This strategy opens new avenues for the design and efficient production of promising electrocatalysts for the ORR.