Optimization of multiple attenuation mechanisms by cation substitution in imidazolic MOFs-derived porous composites for superior broadband electromagnetic wave absorption  

作　　者：Hao Yu Xin Kou Xueqing Zuo Ding Xi Haijun Guan Pengfei Yin Lijia Xu Yongpeng Zhao 

机构地区：[1]College of Mechanical and Electrical Engineering,Sichuan Agricultural University,Ya’an 625000,China [2]College of Resources,Sichuan Agricultural University,Chengdu 610000,China [3]School of Physics,Dalian University of Technology,Dalian 116024,China [4]College of Science,Sichuan Agricultural University,Ya’an 625000,China

出　　处：《Journal of Materials Science & Technology》2024年第9期176-187,共12页材料科学技术（英文版）

基　　金：supported by the Natural Science Foundation of Sichuan Province(No.2023NSFSC0435);Sichuan Agricultural University College Student Innovation Training Program Project Funding(No.202210626019);Sichuan Agricultural University double support(035–2221993150).

摘　　要：Metal-organic frameworks(MOFs)derived composites are extremely potential electromagnetic wave(EMW)absorbers.However,the permittivity of absorbers directly derived from MOFs with solid structure is usually relatively low,inevitably limiting their further applications.Cation substitution can primely overcome the problem by regulating the morphology and atomic space occupation to enhance multiple loss mechanisms and impedance matching characteristics.However,universal mechanisms of the effect on EMW absorption performance influenced by cation substitution are still comparatively inadequate,which prospectively requires further exploration.Herein,a series of imidazolic MOFs were fabricated by ultrasonic symbiosis method and tailored by subsequent cation substitution strategy to prepare target porous composites.At a low filling rate and thin thickness,the as-obtained samples reach the optimal reflection loss and effective absorption bandwidth values of–49.81 dB and 7.63 GHz,respectively.The intercoupling between multiple atoms lays a significant foundation for abundant heterogeneous interfaces and defect vacancies,which effectively ameliorate the attenuation mechanisms.Meanwhile,the porous structure introduced by cation substitution reduces the bulk density to enhance the impedance matching and multiple reflections simultaneously.This study provides a helpful idea to exceedingly improve the EMW absorbing performance of imidazolic MOFs-derived composites by cation substitution.

关 键 词：Multiple attenuation mechanisms Cation substitution Porous composites Electromagnetic wave absorption 

分 类 号：TB33[一般工业技术—材料科学与工程]