Multifunctional Film Assembled from N‑Doped Carbon Nanofiber with Co–N_(4)–O Single Atoms for Highly Efficient Electromagnetic Energy Attenuation  

作　　者：Jia Xu Bei Li Zheng Ma Xiao Zhang Chunling Zhu Feng Yan Piaoping Yang Yujin Chen 

机构地区：[1]College of Materials Science and Chemical Engineering,Harbin Engineering University,Harbin 150001,People’s Republic of China [2]Key Laboratory of In‑Fiber Integrated Optics,College of Physics and Optoelectronic Engineering,Harbin Engineering University,Harbin 150001,People’s Republic of China

出　　处：《Nano-Micro Letters》2024年第11期359-376,共18页纳微快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52372283);China Postdoctoral Science Foundation(Grant No.2023M730826);Heilongjiang Postdoctoral Fund(Grant No.LBH-Z23121);Postdoctoral Fellowship Program of CPSF(Grant No.GZC20233425).

摘　　要：Single-atom materials have demonstrated attractive physicochemical characteristics.However,understanding the relationships between the coordination environment of single atoms and their properties at the atomic level remains a considerable challenge.Herein,a facile waterassisted carbonization approach is developed to fabricate well-defined asymmetrically coordinated Co–N_(4)–O sites on biomass-derived carbon nanofiber(Co–N_(4)–O/NCF)for electromagnetic wave(EMW)absorption.In such nanofiber,one atomically dispersed Co site is coordinated with four N atoms in the graphene basal plane and one oxygen atom in the axial direction.In-depth experimental and theoretical studies reveal that the axial Co–O coordination breaks the charge distribution symmetry in the planar porphyrin-like Co–N_(4) structure,leading to significantly enhanced dielectric polarization loss relevant to the planar Co–N_(4) sites.Importantly,the film based on Co–N_(4)–O/NCF exhibits light weight,flexibility,excellent mechanical properties,great thermal insulating feature,and excellent EMW absorption with a reflection loss of−45.82 dB along with an effective absorption bandwidth of 4.8 GHz.The findings of this work offer insight into the relationships between the single-atom coordination environment and the dielectric performance,and the proposed strategy can be extended toward the engineering of asymmetrically coordinated single atoms for various applications.

关 键 词：Co single atoms Asymmetric coordination structure Axial oxygen coordination Electromagnetic wave absorption Multifunctional film 

分 类 号：O641.4[理学—物理化学] TB383.2[理学—化学]