Double ligand MOF-derived pomegranate-like Ni@C microspheres as high-performance microwave absorber

Abstract

Metal-organic framework (MOF)-derived functional composites have received extensive attention, especially in microwave absorption (MA) materials. However, the delicate design of the spatial structure, designed components, and heterojunction interfaces of MOF derivatives remains a great challenge in the MA application. Herein, a simple double organic ligand strategy and controllable pyrolysis treatment were used to regulate the Ni-MOF derived pomegranate-like Ni@C Microspheres. Their morphology and crystallization can be accurately controlled by a simple hydrothermal method. After pyrolysis, hierarchical magnetic-carbon Ni@C microspheres were obtained which consists of many nickel-carbon core–shell units within the carbon layer. MOF-derived Ni@C microspheres possessed plentiful interfaces, unique three-dimensional conduction network, and magnetic-dielectric synergy system. The pomegranate-like Ni@C microspheres shown excellent microwave absorption performance of a maximum reflection loss (−46.9 dB at 3.5 mm), which can be attributed to the dielectric attenuation, magnetic loss, and matched impedance. Precision regulation of MOF precursors and MOF derivatives provide a novel platform of magnetic-dielectric Ni@C composites that offers excellent MA applications.