Design of 3D lightweight Ti3C2Tx MXene porous film with graded holes for efficient electromagnetic interference shielding performance

Abstract

Ti3C2Tx MXene exhibits excellent prospects in the field of electromagnetic interference (EMI) shielding because of its high conductivity and special 2D structure. However, Ti3C2Tx MXene flakes tend to be stacked due to the interlayer force which makes it difficult to exert its advantages. In this work, 3D lightweight Ti3C2Tx MXene porous film with graded holes were designed and fabricated with a simple template method to overcome the agglomeration and enlighten the inherent advantages of Ti3C2Tx MXene flakes. First, oligo-layered Ti3C2Tx MXene with an average thickness of about 1.96 nm was delaminated, which was further used to construct Ti3C2Tx MXene@PMMA hybrids. Afterward, 3D lightweight Ti3C2Tx MXene porous films with graded holes were controllably fabricated by adjusting the diameter of the PMMA spheres, and in-situ pyrolysis of the template. The relationship between conductivity, structure design, and their EMI shielding properties in K-band (18–26.5 GHz) was investigated. The characterizations revealed that the P1:1Ti3C2Tx with graded holes exhibited high conductivity (297 S/cm) and lightweight (merely 0.1 g/cm3) properties, which displayed a superior EMI shielding effectiveness (SE). The average SET value of P1:1Ti3C2Tx was 60.3 dB with the peak value of 71.4 dB, which was 1.5 times higher than that of Ti3C2Tx flakes in the same condition. The EMI shielding mechanism can be understood from the synergy of polarization loss, conduction loss, impedance mismatch multiple reflection and scattering, and ohmic loss.