Preparation and electromagnetic-wave-absorption properties of nitrogen-doped carbon microsphere/iron cobalt alloy composite

The fast progress in wireless communication technology has significantly intensified electromagnetic interference, underscoring the urgent need for developing high-efficiency, low-cost microwave-absorbing materials (MAMs). The current work synthesizes polydopamine microspheres, which can adsorb Co²⁺ and Fe³⁺, followed by the preparation of a nitrogen-doped carbon microsphere/iron cobalt alloy composite microwave absorbing material (NCS/FeCo) <i>via in situ</i> reduction through high-temperature calcination. Additionally, the surface morphology, surface element composition, hysteresis loop, and electromagnetic parameters were investigated, and the reflection loss (RL) was obtained to explore the absorbing mechanism. The results demonstrated that at a 2.5 mm NCS/FeCo thickness, the maximum RL at 13.4 GHz was -55.3 dB, with the corresponding effective absorption bandwidth (EAB) of 11.28 GHz (6.72-18 GHz). Furthermore, the material exhibits excellent microwave-absorbing properties, providing valuable insights to develop efficient microwave-absorbing materials.