Synergistic effect of nickel selenide‑carbon composites for efficient broadband electromagnetic wave absorption

Novel NiSe2-based composites loaded with carbon nanotubes (CNTs) and graphene (GNs), respectively, were successfully synthesized via a facile hydrothermal reaction, aiming to enhance the electromagnetic wave (EMW) absorption performance. Microstructure, morphology, dielectric properties and EMW absorption performance of as-prepared NiSe2/CNTs and NiSe2/GNs composites were explored. Results showed that both NiSe2/CNTs and NiSe2/GNs composites exhibited improvement in EMW absorption compared to pure NiSe2, especially NiSe2/GNs showed the best EMW absorption performance. NiSe2/GNs composites demonstrated an exceptional minimum reflection loss (RLmin) of −52.10 dB at a thin thickness of merely 1.71 mm, accompanied by a wide effective absorption bandwidth (EAB) of 4.1 GHz. However, the EMW absorbing performance of NiSe2/CNTs composites was slightly lower than that of NiSe2/GNs composites, showing an RLmin of −45.10 dB and an EAB of 3.76 GHz at a thin thickness of 1.60 mm. Such significantly enhanced absorption capability of NiSe2/GNs composites can be attributed to the synergistic interplay of desirable impedance matching and efficient attenuation ability. These findings highlight the potential of NiSe2-based composites loading with carbon conductive fillers as highly promising contenders for high-performance EMW absorption materials.