Multiple dimension-component designed Co/Co9S8/Ti3C2Tx MXene composite for enhanced microwave absorption

The two-dimensional (2D) transition metal carbide Ti3C2Tx MXene is a potential candidate for efficient electromagnetic wave absorbers due to its excellent intrinsic conductivity and structural machinability. However, Ti3C2Tx MXene also has some problems (such as self-stacking and single loss mechanism) that limit its practical electromagnetic wave absorption. Based on the electromagnetic wave absorption mechanism, electromagnetic responsiveness of absorbers can be modulated by designing the composition and structure. Herein, a 1D/2D Co/Co9S8/Ti3C2Tx composite has been synthesized by assembling 2D Ti3C2Tx MXene with the designed 1D magnetic structure. The 1D Co/Co9S8 was designed as a core-sheath structure that avoids magnetic agglomeration, and the assembly with 2D Ti3C2Tx sheets alleviates the self-stacking problem of Ti3C2Tx MXene sheets. More importantly, the magnetic component enriches the electromagnetic wave dissipation mechanism, and the multiple heterojunction surfaces provide strong polarization loss capability for the Ti3C2Tx MXene-based absorber. Benefiting from the unique structure and dielectric-magnetic synergistic loss, the Co/Co9S8/Ti3C2Tx composite shows an effective absorption bandwidth of 5.36 GHz (10.08–15.44 GHz) at 2.1 mm and the optimal RLmin value of −52.02 dB at 1.8 mm. This work provides an innovative idea for the design of effective Ti3C2Tx MXene-based absorbers.