Flexible and Lightweight Hollow MXene@Carbon Microfiber Composites for Microwave Absorption and Light-Responsive Devices

To address the increasing demand for improved security, integration, and intelligence in microwave technology, it is crucial to develop lightweight and broadband microwave-absorbing materials (MAMs) with multifunctional properties and to construct corresponding electromagnetic devices. This study fabricates hollow MXene@Carbon microfibers through a biomass-templating and electrostatic self-assembly strategy, which were subsequently assembled with polydimethylsiloxane to produce flexible, lightweight and thermally stable composites. Owing to one-dimensional hollow structure and multi‑component synergy, the composite demonstrates exceptional lightweight broadband microwave absorption along with efficient photothermal conversion performance. The effective absorption bandwidth reaches 7.08 GHz (1.77 mm) and 8.92 GHz (2.4 mm), corresponding to specific absorption bandwidths of 36.7 and 35.4 GHz g⁻¹ cm², respectively, while the visible light absorption attains 97%. Furthermore, a device integrating microwave stealth and light‑responsive power generation functions was designed and characterized. This device not only achieves microwave radar stealth but also generates stable and tunable voltage output under light illumination. This work not only advances the development of MAMs but also provides a novel strategy for designing multifunctional electromagnetic devices.