Effect of Surface Structure and Composition on the Electromagnetic Properties of Ti3C2T x MXenes for Highly Efficient Electromagnetic Wave Absorption

In this paper, two-dimensional Ti3C2T x -MXenes with abundant defects and functional groups as well as appropriate conductivity were successfully synthesized by acid treatment at room temperature. The relationship between the surface structure and its electromagnetic wave absorption ability was systematically studied by changing etching time and heat treatment. Benefiting from the conduction loss and strong polarization relaxation around the abundant interface areas in the two-dimensional layered structure, the Ti3C2T x Mxene composite possesses excellent electromagnetic absorption performance. Remarkably, optimized Ti3C2T x exhibits extremely strong absorption with a minimum reflection coefficient of −65 dB, and the qualified absorbing bandwidth is up to 5 GHz. Furthermore, the ultrathin matching thickness of the Ti3C2T x Mxene composite is 1.4 mm. The prominent absorbing performance outperforms most recently reported two-dimensional carbon materials for microwave absorption.