A two-dimensional semiconductive Cu-S metal-organic framework for broadband microwave absorption

Electromagnetic radiation and pollution are urgent and crucial problems to be solved. Metal-organic framework (MOF) derivates play an important role in the attenuation of electromagnetic waves efficiently. However, limited by the complex pyrolysis process, the chemical composition and crystal structure of MOF were totally destroyed. Inspired by the electrical window (10(-6)-10 S.cm(-1)) of microwave absorption materials (MAMs), semiconductive MOF with precise crystal structure is potential to be an ideal microwave absorbent. This work reports a two-dimensional (2D) semiconductive MOF (Cu-S-MOF) as broadband high-performance MAMs. The effective absorption bandwidth (EAB) of the Cu-S-MOF can reach 6.72 GHz (9.68-16.4 GHz) at a thickness of 1.5 mm, and a minimum reflection loss (RLmin) value of -52.8 dB at 1.69 mm. Due to the absence of the pyrolysis process, a well-defined single-crystal structure of Cu-S-MOF can be obtained. A density functional theory (DFT) calculation was performed to illuminate the microwave absorption mechanism. Resistance loss and interfacial polarization loss between the Cu-S layers mainly contribute to the Cu-S-MOF MAMs. The semiconductive MOF towards MAMs provides a facile and effective strategy to tune microwave absorption performance, which can be applied in the electromagnetic protection field.