聚酰亚胺衍生多孔碳纳米片中的协同分子组装与阻抗匹配及其微波吸收性能研究OA

Herein,a novel strategy for fabricating microwave absorption materials via molecular-level design that synergistically regulates dielectric and magnetic losses.The method utilizes a polyimide precursor containing both carboxyl and benzimidazole functional groups as the key component.Through an ice-templating process followed by in-situ ion exchange,Ni²⁺ ions are uniformly incorporated into the polymeric skeleton.Subsequent thermal imidization and carbonization yield nitrogen-doped two-dimensional carbon nanosheets embedded with uniformly dispersed Ni/NiO nanoparticles(BPCN@Ni/NiO).This material exhibits significantly superior microwave absorption properties compared to its counterpart synthesized without the benzimidazole structure(NPCN@Ni/NiO).BPCN@Ni/NiO achieves a remarkable minimum reflection loss(RLmin)of-69.02 dB with effective absorption bandwidth(EAB)of 8.92 GHz(8.28-17.2 GHz).Microstructural analyses confirm its three-dimensional interconnected nanosheet architecture,highly dispersed Ni/NiO species,and homogeneous elemental distribution.The performance enhancement is attributed to the synergistic complexation of Ni2+ions by benzimidazole and carboxyl groups,which enables efficient loading and uniform dispersion of nickel species,thereby optimizing impedance matching.Furthermore,the unique 2D conductive network,abundant heterogeneous interfaces(C/Ni/NiO),defect-induced dipole polarization,and magnetic coupling between Ni and NiO collectively contribute to synergistic multiple loss mechanisms,ultimately endowing the material with excellent microwave attenuation capability.This work offers a new pathway for designing lightweight,efficient,and broadband carbon-based composite absorbers through precise molecular engineering.