Non-woven fabrics of columnar-cactus-like MXene@rGO fibers with efficient electromagnetic absorption

The escalating demand for electromagnetic protection against increasingly severe electromagnetic pollution is making the development of advanced electromagnetic wave absorbing material systems imperative. MXene-based electromagnetic wave absorbing fillers demonstrate advantages of lightweight and high efficiency. However, their microscale dimensions hinder the formation of interconnected networks within matrices, resulting in limited EM loss mechanisms and narrow effective absorption bandwidths. Herein, we employ wet spinning combined with molten salt-assisted in-situ synthesis to fabricate MAX@rGO (rGMAX_n) fibrous absorbers featuring a hierarchical structure of “columnar cactus covered with MAX spheres”. Precise regulation of MAX phase content enables controlled tuning of the electromagnetic properties of rGMAX_n fibers. Moreover, subsequent in-situ etching further enhances their EM performance, yielding MXene@rGO (rGMX_n) fibers with a hierarchical structure of “columnar cactus decorated with MXene nanosheet clusters”. Freeze-drying is utilized to modulate fiber filling content, and fibrous felts with conductive networks are obtained, which exhibit excellent electromagnetic wave absorption performance. Among them, the as-prepared rGMX₁₀ fibrous felt exhibits good electromagnetic wave absorption performance at a low filling content (10 wt.%) with the RL_max of 54.4 dB and an effective absorption bandwidth of 5.31 GHz. This enhancement originates from improved impedance matching characteristics through fiber-interconnected networks and multiple electromagnetic loss mechanisms enabled by the hierarchical structure. The strategy of in-situ growing hierarchical MXene@rGO fibers establishes a novel approach for developing MXene-based fibrous absorbing materials.