Preparation and absorbing properties of ultra-light and large size hollow cubic carbon materials

In this paper, using NaCl as the template and in-situ polymerized phenolic resin as the carbon source, we prepared micron-sized large hollow cubic carbon. With the increase of stirring speed, the particle size, cavity size and shell thickness of hollow cubic carbon (HCCs) increased gradually. The sample with stirring speed of 1500 r/min (HCCs-5) obtained strong loss capacity (RL_min = − 43.99 dB), wide bandwidth (EAB = 5.22 GHz) and thin thickness (2.0 mm) under very low load (1.5 wt%), taking into account the requirements of “strong, wide, light and thin” of modern wave absorbing materials. The hollow cube structure of HCCs can make the electromagnetic wave be reflected several times in its interior, and the electromagnetic wave is lost. The formation of a three-dimensional conductive network between adjacent HCCs will lead to an increase in conductivity and a certain conduction loss. More importantly, the mesoporous structure provides interfacial polarization, and the synergy of these loss mechanisms together ensures excellent wave absorption performance.