Trimetallic Prussian blue analogue derived FeCo/FeCoNi@NPC composites for highly efficient microwave absorption

Recently, Prussian blue analogues (PBA) have emerged as attractive precursors or templates for the construction of porous carbon-based microwave absorption (MA) materials because of their open framework, tunable components and mild synthesis conditions. Herein, for the first time, trimetallic FeCoNi-PBA nanocubes are introduced as precursors, and then a novel core-shell structured composites, in which FeCo and FeCoNi alloy nanoparticles are uniformly encapsulated in N-doped porous carbon (FeCo/FeCoNi@NPC), are successfully synthesized via a pyrolysis process. Benefiting from the strong synergetic effects among multiple components (FeCo, FeCoNi alloys and N-doped carbon species) and the hierarchical porous structure, the absorber exhibits significantly enhanced MA performance in comparison with FeNi@NPC and FeCo@NPC derived from bimetallic PBAs. Impressively, the minimum reflection loss (RL) is up to -67 dB at 14.7 GHz with a thin thickness of 1.91 mm, and the corresponding effective absorption bandwidth (EAB) reaches 6.24 GHz, covering the whole Kuband. When the thickness is 2.05 mm, the maximum EAB of 6.6 GHz can be obtained. In particular, the absorber can also achieve full absorption of X-band at 2.68 mm. More importantly, the multi-metallic PBA derivation strategy sheds new light on development of lightweight carbon-based absorbers with high performance, low cost and easy synthesis.

Automated summary

This study successfully synthesized a novel trimetallic PBA nanocomposite with a core-shell structure and hierarchical porous properties, which exhibited significantly enhanced microwave absorption performance and wideband absorption at thin thickness.