In situ encapsulation of heterostructures induced microscopic factors to enhance polarization loss of transition metal sulfides microwave absorbers

Abstract

With the rapid development of modern electronic devices, electromagnetic wave pollution has become increasingly severe. In the field of materials science research, developing superior microwave absorbers holds immense importance. Light-weight carbon nanotube composites are developed for their unique electronic structure and excellent mechanical properties for wide applications in electronics, communication devices, and other specific parts, considering ideal candidates for the preparation of new types of electromagnetic wave absorption materials. This study focuses on embedding Fe7S8/FeS2 heterostructures into nitrogen doped carbon nanotubes through in-situ packaging to optimize interface engineering and improve the electromagnetic wave absorption efficiency of the material. Through pyrolysis and sulfidation processes, we successfully synthesized Fe7S8/FeS2 heterostructures in situ encapsulated within N-doped carbon nanotubes (NCNTs). Fe7S8/FeS2/NCNT shows microwave absorbing ability with a strong absorption (−36.83 dB at 14.08 GHz with a small thickness of 1.6 mm) and a broad effective absorption bandwidth (5.14 GHz). The excellent microwave absorption capability is mainly attributed to the efficient conductive network of NCNTs and the synergistic effect of Fe7S8/FeS2 heterostructures. This not only confirms the potential of transition metal sulfides/NCNTs composites in microwave attenuation applications, but also provides new strategies for the design and development of future microwave absorbers.