MOF-derived Co/ZnO/C nanocomposites with excellent microwave absorption properties

Magnetic nanoparticles combined with semiconductive metal oxides are considered to be ideal candidates for electromagnetic wave absorption materials, benefiting from suitable conductivity, matched magnetism and strong polarization. In this work, Co–ZnO binary MOF (ZIF-67, ZIF-8)-based carbon composites were fabricated via a facile synthesis route. After optimization of composition and technological parameters, the synthesized nanocomposites acquired optimal electromagnetic characteristics and exhibited superb microwave absorption ability. The lowest reflection loss of the Co–ZnO–C-800 sample reached − 44.8 dB at 9.2 GHz with a thickness of 2.9 mm, and the effective absorption bandwidth (EAB) was 6.95 GHz (6.59–13.54 GHz). The microwave loss mechanism of the nanocomposite material mainly involved dielectric loss and magnetic resonance absorption. This work provides an ingenious design and synthesis strategy for novel lightweight electromagnetic wave absorbers with broadband EAB and strong absorption.