南昌航空大学彭玉辉《Carbon》:风琴状氮掺杂Co/碳纳米片复合材料，用于宽带电磁波吸收

图1. (a) Fabrication process of Co/NCNS-T. (b) XRD patterns, (c) Raman spectra of Co/NCNS-6, Co/NCNS-7, Co/NCNS-8, and Co/NCNS-9.

图2. SEM images of (a, b) Co/NCNS-6, (c, d) Co/NCNS-7, (e, f) Co/NCNS-8 and (g, h) Co/NCNS-9, XPS analysis of Co/NCNS-T: (i) survey spectrum, (j) C 1s, (k) Co 2p, (l) N 1s; (m) N species contents of Co/NCNS-T. (n) magnetic hysteresis loops of Co/NCNS-T.

图3. (a-c) TEM, (d-f) HRTEM and (g) SEM-EDS element mapping images of Co/NCNS-8 composite.

图4. 3D RL mappings and corresponding 2D RL curves of (a, b) Co/NCNS-6, (c, d) Co/NCNS-7, (e, f) Co/NCNS-8 and (g, h) Co/NCNS-9.

图5. Electromagnetic parameters of Co/NCNS-T, including (a-b) real and imaginary parts of permittivity, (c) dielectric loss tangent, (d-e) real and imaginary parts of permeability, and (f) magnetic loss tangent.

图6、(a) Electric field, magnetic field distributions, and power loss density of Co/NCNS-8 at 17.6 GHz. (b-e) 3D radar wave scattering maps of Co/NCNS-6, 7, 8, 9. (f) RCS simulated curves of PEC and Co/NCNS-T composites. (g) RCS reduction values of Co/NCNS-T at various angles.

图7. Schematic diagram of possible EMW attenuation mechanisms in Co/NCNS-T.

综上所述，通过调制退火温度，从dia-Co(MeIm)2框架中合成了具有手风琴状结构的Co-MOF复合材料。高温热解形成了由 0D Co 颗粒、1D CNT 和 2D NCNS 组成的三维结构。由此产生的 Co/NCNS 吸收体集成了三维导电网络、丰富的异质界面，并通过掺杂杂原子增强了偶极极化。在850 °C 的最佳煅烧温度下，Co/NCNS-8会产生磁共振，从而提高磁损耗并优化阻抗匹配。因此，Co/NCNS-8 在厚度为1.56mm时的RLmin为 -49.1dB，在厚度为1.79mm时的最大EAB为6.64GHz。CST 仿真证实，Co/NCNS能在实际条件下有效耗散电磁波能量，为高性能电磁波吸收材料的设计提供了可靠的参考。