Currently, the development of artificial intelligence and new-generation high-frequency communication technologies has placed increasingly higher demands on the performance of electromagnetic wave (EMW) absorbing materials with multiple functions in complex application scenarios. In this work, using Cu sphere@ZIF-67 composites as the precursor, the Cu sphere@ZIF-derived Co particles/carbon fiber flexible (CCC) composites are designed by electrostatic spinning and high-temperature calcination technique. Herein, a specific cross-linked structure is formed with the inset of ZIF-derived Co particles and Cu spheres into the CNF network, allowing effectively tuning the electromagnetic parameters, optimizing the impedance matching and improving the EMW absorption performance of CCC composites. The as-obtained composites gain a high minimum reflection loss (RL_min) of −78.33 dB and a broad effective absorption bandwidth (EAB) of 7.60 GHz. Apparently, the three-dimensional interlaced complex network structure endows the composites with enhanced thermal conductivity and superhydrophobic properties, making it conducive to heat transfer and inhibiting the absorption of surface water. Meanwhile, the conductivity of the composites is greatly sensitive to the bending deformation, enabling their applications in flexible sensing. Briefly, this work provides a novel and feasible design thought to fabricate carbon-based composites with multifunctional properties of EMW absorption, heat-conducting, self-cleaning and strain-sensitive conductivity, which opens a route for the potential application of EMW absorbing materials under some extreme conditions.

The morphology manipulation of nanomaterials by ion irradiation builds a way to precisely control physicochemical properties. Under the continuous irradiation of low energy Ga⁺, Ne⁺, and He⁺ ions, an ion compaction effect has been found in hollow FePt nanochains with ultrathin shell that the volumes of the nanochains are gradually compacted by ions. The deep learning algorithm has been successfully applied to automatically and precisely measure average sizes of spheres in hollow FePt nanochains. The compaction under ion irradiation is very fast in the very early period and then proceeds to a slow region. The compaction rates in both regions are linearly fitted and all the values are in the order of 10^–17 to 10^–14 cm²/ion. Ion species and ion current have effect on the compaction rate. For example, the compaction rate of Ga⁺ ions is larger than those of Ne⁺ and He⁺ ions under an identical current, while irradiation with larger current can compact nanochains faster. The ion compaction effect originates from the local shear deformation caused by the interaction between incident ions and the electrons of Fe and Pt atoms in the ultrathin shell. With continuous irradiation, the crystalline clusters of FePt nanchains firstly grow larger and then become amorphous. The ion compaction effect can be applied to tune the size and crystal structure of hollow structures with a precise rate by choosing appropriate ion species and current.