Self-Alignment of MXene Films Induced by Electrostatic Repulsion from TaS2 Nanosheets for Multifunctional Applications.

Abstract

Fabricating freestanding films with pristine MXene aims at meeting all-around high standards of modern electronics through boosting high electrical conductivity, thermal conductivity, and robust mechanical strength. However, voids and defects arising during fabrication often limit the performance and versatility. An effective electrostatic repulsion-induced alignment strategy is suggested here to overcome the major obstacles in the industrial application of MXene films. This approach combines polydopamine (PDA)-modified MXene with two-dimensional (2D) tantalum disulfide (TaS2) nanosheets to enhance the alignment and compactness of MXene layers. Incorporating a small amount of TaS2 nanosheets, which carry negative charges, facilitates the alignment of PDA-modified MXene sheets during film assembly via electrostatic repulsion. This results in the fabrication of strong and well-ordered composite films with a synergistic effect between MXene and TaS2. The resultant MXene/TaS2 (MXT) films exhibit high mechanical strength (92 MPa), toughness (2.49 MJ·m-3), excellent electrical conductivity (7932 S cm-1), electromagnetic interference (EMI), shielding effectiveness (SE) (62 dB), and superior in-plane thermal conductivity (53.19 W·m-1·K-1). In addition, MXT films demonstrate remarkable Joule heating performance and environmental stability.