Polypyrrole/γ-Fe2O3/g-C3N4 nanocomposites for high-performance electromagnetic wave absorption

Magnetic/dielectric composites offer good impedance matching for electromagnetic wave absorption, though achieving both strong absorption and broadband absorption in such composites is challenging. Herein polypyrrole-Maghemite-graphitic carbon nitride (PPy/γ-Fe2O3/g-C3N4) composites were successfully fabricated via the one-step chemical synthesis of PPy/γ-Fe2O3 nanospheres in the presence g-C3N4 nanosheets. The PPy/γ-Fe2O3/g-C3N4 composites demonstrated outstanding electromagnetic wave (EMW) absorption properties at microwave frequencies. A compositionally optimized PPy/γ-Fe2O3/g-C3N4 composite delivered a minimum reflection loss (RLmin) value of −53.66 dB at 11.92 GHz and the effective absorption bandwidth (EAB, RL < −10 dB) of 5.13 GHz (10.46–15.59 GHz) at a thickness of 2.5 mm. The excellent EMW absorption properties of the composite could be attributed to the introduction of g-C3N4 nanosheets with a lamella structure, which enhanced interfacial polarization losses, multi-reflections, scattering, and impedance matching within the composite. This work offers a simply and effective strategy for the preparation of high-performance EMW absorbers.