Synthesis of Ti3C2Tx MXene/Ni Nanoparticles Composite with Tunable Particle Size for High-Performance Microwave Absorption

A significant challenge metal nanoparticles (NPs) used for electromagnetic wave (EMW) is the precise regulation of the interplay between dielectric and magnetic losses through multi-scale interface engineering, as well as achieving a wide broadband for absorbing materials. In this study, Ti 3 C 2 T x MXene/Ni composites were successfully synthesized in situ via a simple and mild solvothermal method. The influence of the size of Ni NPs on the EMW absorption performance was investigated. The results demonstrate that the size of Ni NPs could be regulated by varying the Ti 3 C 2 T x MXene content, resulting in a synergistic balance between dielectric and magnetic losses, significantly improving wideband impedance matching (3.00–12.80 GHz). The Ti 3 C 2 T x MXene/Ni composites achieved a minimum reflection loss (RL m ᵢ n ) of −50.70 dB at 3.76 GHz, with an effective absorption bandwidth (EAB) of 3.20 GHz. Characterization results reveal that size-dependent permeability dispersion and dielectric relaxation behavior synergistically optimize both impedance matching and loss mechanisms. This study provides a novel design strategy for enhancing the electromagnetic attenuation performance of MXene-based composites.