Design of dual-frequency electromagnetic wave absorption by interface modulation strategy

Design of highly efficient electromagnetic wave (EMW) absorbing materials with continuous dual-absorption peaks is a hot topic but a challenge in anti-electromagnetic interference and pollution fields. Herein, we developed an interfacial modulation strategy to achieve this goal in dielectric nanocomposite and clarified the interface function and relevant mechanism. Experimentally, CuS/Ag₂S composite with tunable heterointerface was fabricated by decorating Ag₂S nanoparticles on CuS flakes via cation-exchange reaction. By changing the Ag₂S loading, the heterointerface between Ag₂S and CuS induced strong dielectric resonant peak and improved impedance matching, which resulted in the significant enhancement of EMW absorption and the appearance of continuous dual-absorption peaks in CuS/Ag₂S composite. With a rather low filler loading of 20 wt% and a thin layer thickness of 2.89 mm, the optimized CuS/Ag₂S composite exhibited continuous dual-absorption peaks with reflection losses of −47.2 and −20.6 dB, respectively. The proposed interfacial modulation strategy may potentially be used to fabricate other highly efficient dual-absorption absorbers.