MXene@Cu@PPy nanocomposites with enhanced electromagnetic response

Bilayer MXene@Cu and trilayer MXene@Cu@PPy nanocomposites were synthesized for lightweight, thin X-band (8–12 GHz) electromagnetic wave absorbers. Ti 3 AlC 2 MAX phase was prepared via molten-salt synthesis at 1050 °C, etched with HF to yield Ti 3 C 2 Tₓ MXene nanosheets, then loaded with Cu (0.5–4 mol%) via precipitation, and coated with PPy through in-situ polymerization. Low Cu loadings in MXene@Cu enabled optimal conductivity, strong interfacial polarization, and impedance matching (|Zin/Z0| ≈ 1), yielding high reflection loss (RL). High Cu disrupted matching, weakening absorption. PPy addition in ternary NCs increased polarization interfaces, stabilized conductivity, enhanced matching, and boosted dielectric/magnetic losses, improving RL across Cu ratios. Analysis of permittivity, permeability, attenuation, and Cole–Cole plots confirms balanced conductivity, polarization, magnetic loss, and matching as key to superior performance. This MXene–metal–polymer design advances broadband EMWA materials.