Regulating pyrolysis strategy to construct CNTs-linked porous cubic Prussian blue analogue derivatives for lightweight and broadband microwave absorption

Abstract

Metal-organic framework (MOFs) derived carbon-based nanocomposites are considered as a class of new microwave absorption materials with great application potential. However, it remains a challenge to obtain high-efficiency absorbers based on MOFs with lower filling ratio and wider effective absorption band. In addition, it is difficult to construct uniform interconnection networks of carbon nanotubes (CNTs) in situ on the surface of MOFs derivatives by simple method. Here, we innovatively combined the pyrolysis laws of Co-based Prussian blue analogue (PBA) with the mechanisms of CNTs synthesis catalyzed by Co nanoparticles, and prepared CNTs-linked cubic porous PBA derivative (CoCN@CNT) through a designed pyrolysis process. Results show that when a temperature plateau was added and the final pyrolysis temperature was controlled to 700 ℃, the obtained sample has a unique morphology and the best microwave absorption performance. When the filling ratio is only 20%, it could exhibit an ultra-wideband effective absorption of 6.35 GHz with a matching thickness of 2.5 mm, covering the entire Ku radar band. This work provides theoretical support for the controllable growth of metal-catalyzed CNTs, as well as novel insights for the design and facile synthesis of high-performance micro-nano-scale microwave absorbers.