Promoting electromagnetic wave absorption for conductive metal–organic frameworks through crystal morphology controlling

Abstract

Conductive metal–organic frameworks (cMOFs) with π-d conjugation that can effectively promote the transport and migration of free electrons and improve electrical conductivity are considered as potential high-efficiency electromagnetic wave (EMW) absorption materials. However, the microstructural regulation of cMOFs with highly efficient EMW absorption remains a challenge due to the complexity of organic ligands and the uncontrollability of self-assembly reactions. Herein, two distinctly different microstructures or morphologies of Ni-TABQ cMOFs are synthesized by assembling the 2,3,5,6-tetraaminobenzoquinone (TABQ) ligands and Ni²⁺ ions through the manipulation of different reaction environments. The synergistic effect between the intrinsic conductivity and bulk microstructure of the obtained Ni-TABQ-1 optimizes electromagnetic parameters, displaying outstanding EMW absorption performance, with an RL_min value of −62.68 dB at 2.94 mm and an EAB of 5.12 GHz. These results demonstrate that the microstructural and conductivity control of cMOFs could offer an accessible and positive guide to developing superior EMW absorption materials.