Advanced CuS/g‑C3N4/Fe3O4 Nanostructures for Broadband Microwave Absorption

In recent years, the demand for micronano materials with superior microwave absorption capabilities has been on the rise, such as strong absorption capacity, lightweight, and wide frequency bandwidth, to tackle the issues associated with electromagnetic microwave (EMW) pollution. Here, the CuS/g-C3N4/Fe3O4 nanocomposite was fabricated using a simple mechanical stirring, hydrothermal treatment, and high-temperature calcination, composed of graphitic carbon nitride (g-C3N4), micron-sized flower-like copper sulfide (CuS), and iron oxide nanoparticles (Fe3O4). The CuS/g-C3N4/Fe3O4 nanocomposite has an excellent EMW absorption performance. The results show that the maximum reflection loss (RLmax) of the CuS/g-C3N4/Fe3O4 nanocomposite could achieve −41.2 dB at a frequency of 13.7 GHz with a thickness of 2.5 mm, corresponding to an ultrawide effective absorption bandwidth (RL < −10 dB) of 8.6 GHz (9.4–18 GHz). The excellent EMW properties of the CuS/g-C3N4/Fe3O4 nanocomposite are attributed to various mechanisms such as multidimensional multilevel scattering, interfacial polarization, and magnetic decay processes. The unique three-dimensional (3D) structure of the CuS/g-C3N4/Fe3O4 nanocomposite holds promise in providing ideas and solutions for the advancement of EMW technology in the future.