Regulating surfactant strategy to synthesize Co@NCNT nanocomposites with conductive networks towards excellent electromagnetic wave absorption

In this paper, Prussian blue analogues (PBAs) with different morphologies have been synthesized in a co-precipitation process with Na 3 C 6 H 5 O 7 ·2H 2 O and polyvinyl pyrrolidone (PVP) as surfactant, and then the electromagnetic wave absorption (EMWA) properties of their derivatives obtained via a pyrolysis reaction were investigated. To explore the best suitable pyrolysis temperature, PBA precursor synthesized via the addition of Na 3 C 6 H 5 O 7 ·2H 2 O was annealed at four different temperatures (550/650/750/850 °C) to obtain the cobalt encapsulated in nitrogen-doped carbon nanotube (Co@NCNT) nanocomposites. Our results show that when the pyrolysis temperature is 650 °C, the Co@NCNT shows a minimum reflection loss (RL min ) of - 43.95 dB at the thickness of 2.05 mm, and the effective absorption bandwidth reaches 5.695 GHz, spanning the X and Ku bands. The excellent EMWA property is ascribed to the synergistic effect of dielectric and magnetic loss.