Porous C/Co (derived from ZIF-67) embedded in anazotic g-C3N4 (PC/Co/ACN) composite as a super electromagnetic wave absorber

Zeolitic imidazolate frameworks (ZIFs) show great potential in the field of electromagnetic wave (EMW) absorption due to their unique structures. However, low permittivity limits their further application. In this study, anazotic g-C3N4 (ACN) with a high dielectric constant was produced by reducing g-C3N4 with Mg powder. Then, a series of PC/Co/ACN-x (x indicates the mass ratio of ACN and ZIF-67) EMW absorbers was produced. Additionally, the EMW absorption capacity of PC/Co/ACN with different filling amounts was compared. The best sample was PC/Co/ACN-7.5 with 8 wt% filling; it had a minimum reflection loss (RLmin) of −43.52 dB (over 99.99% absorption) and effective absorption bandwidth (EAB, RL < −10 dB) of up to 6.21 GHz. This work provides a new approach for the preparation of high dielectric carbon sheet and ZIF derivates in the EMW absorption field.