Microwave absorption properties of CoS₂/TiO₂/Ti₃C₂T_x MXene composites

Cobalt disulfide (CoS₂) nanoparticles were combined with varying amounts of MXene (Ti₃C₂T_x) sheets via a hydrothermal method for microwave absorption applications. X-ray diffraction confirmed the coexistence of crystalline CoS₂, Ti₃C₂T_x, and TiO₂ phases, revealing the partial surface oxidation of Ti₃C₂T_x sheets. Scanning electron microscope images demonstrated that CoS₂ nanoparticles were uniformly anchored on the MXene sheets, and X-ray photoelectron spectra showed the presence of Co-S, Ti-C, and Ti-O bonds, indicating strong interfacial interactions. The CoS₂-35 wt % Ti₃C₂T_x composite exhibited a minimum reflection loss of -15.23 dB at a matching thickness of 2.4 mm and a broad effective absorption bandwidth of 7.3 GHz (from 10.7 to 18 GHz) at 3.2 mm, which was mainly attributed to impedance matching. Synergistically, the presence of multiple interlayer interactions and the extension of the wave-propagation path within the layered microstructure of the CoS₂-35 wt % Ti₃C₂T_x composite mutually contribute to wave attenuation.