Porous carbon nanorods decorated with graphitic carbon bubbles encapsulated NiSe nanoparticles as an efficient microwave absorber

Abstract Microwave absorbers have been applied extensively to attenuate harmful electromagnetic radiation. In this study, efficient microwave absorbers are successfully prepared using metal-organic frameworks as precursors through a convenient in-situ growth and selenization approach in which NiSe nanoparticles are embedded in rod-like carbon networks decorated with graphitic carbon bubbles. The chemical composition, microstructure, graphitization degree, and corresponding microwave absorption performance are well controlled by changing the selenization condition. Remarkably, the reflection loss of the NiSe/C composite obtained at 700 °C reached −59.70 dB at 7.89 GHz and the effective absorption bandwidth was 4.67 GHz. In the as-prepared composite, pervasive carbon networks help improve conductive loss. The homogeneous interfaces between metal selenides and carbon, as well as the abundant defects and interfaces in the graphitic carbon bubbles, boost interfacial polarization and accelerate electron transfer, contributing to the high-performance absorption.