Construction of 2D/2D heterostructure with porous few layer g-C3N4 and NiCo2O4 nanosheets towards electromagnetic wave absorption

Developing high-performance materials with ultra-high reflection loss (R_L ≤ −65 dB) for electromagnetic wave (EMW) absorption is pivotal to address electromagnetic pollution, but it is still challenging. Herein, a two-dimensional (2D)/2D PFL g-C₃N₄/NiCo₂O₄ heterostructure with porous few-layer g-C₃N₄ (PFL g-C₃N₄) and ultrathin NiCo₂O₄ nanosheets has been prepared by self-assembly, hydrothermal reaction, and calcination strategies. The 2D/2D heterostructure exhibits extraordinary EMW absorption property, achieving a reflection loss (R_L) value of −68.59 dB and an effective absorption bandwidth (EAB) of 1.92 GHz at a matching thickness of 2.5 mm. As expected, the porous few layer g-C₃N₄ nanosheets provide rich interface which increases multiple reflection paths and enhances the conduction loss. The cooperative effects of magnetic loss, dielectric loss, and impedance matching contribute to the exceptional EMW absorption property of PFL g-C₃N₄/NiCo₂O₄ (2D/2D) heterostructure. The potential of PFL g-C₃N₄/NiCo₂O₄ in actual radar stealth is verified through radar scattering cross-section (RCS) simulation. This work paves the way for utilizing 2D/2D heterostructure as an ultra-efficient EMW absorbers.