Engineering hierarchical multilevel microstructures of CoNC/rGO aerogel originated from interfacially ordered ZIF-L nanosheet arrays for superior electromagnetic wave dissipation

Abstract

Rational manipulation of hierarchical microarchitecture engineering has emerged as a highly appealing approach to achieving exceptional electromagnetic wave (EMW) absorption performance in carbon-based aerogel absorbers. However, inadequate interfacial engineering and impedance mismatch pose significant obstacles to optimizing EMW absorption, primarily due to the limitations in current construction strategies. Herein, multilevel heterogeneous carbon-based aerogels, Co/N-doped carbon nanosheets tightly anchored on reduced graphene oxide aerogel (CoNC/rGO), have been fabricated through in-situ growing interfacially ordered bimetallic Co/Zn-ZIF-L nanoarray on chitosan crosslinked graphene oxide aerogel (ZIF/CS-GO), followed by a pyrolysis process. The resultant CoNC/rGO aerogels exhibit a multilevel interfacial effect and a 3D interconnected dielectric network, leading to substantial enhancements in polarization loss and dielectric-magnetic coupling synergy, along with optimized impedance matching. Consequently, the optimized CoNC/rGO-3/1 and CoNC/rGO-1/1 aerogels demonstrate impressive EMW absorption performance, characterized by strong and broad absorption capabilities. Specifically, the maximum reflection loss (RL) values for CoNC/rGO-3/1 and CoNC/rGO-1/1 reached −56.6 dB at 2.4 mm and −58.1 dB at 3.1 mm, respectively. Additionally, these aerogels achieved broad effective absorption bandwidths (EAB) of 5.04 GHz and 4.56 GHz at a thickness of 1.8 mm, respectively. This work provides an effective and innovative strategy for developing of advanced EMW absorbers in carbon-based aerogels by rationally constructing multilevel heterogeneous interfaces, utilizing metal-organic frameworks (MOFs) as foundational building blocks.