Scalable, Highly Conductive, and Micropatternable MXene Films for Enhanced Electromagnetic Interference Shielding

Two-dimensional transition metal carbides and nitrides (MXenes) have accumulated tremendous interest recently due to their high conductivity and excellent figures of merit in electromagnetic interference shielding and other applications. Large-area freestanding films of MXenes are important for versatility in application; however, alternative processing methods are needed for large-scale production. In this work, we demonstrate fabrication of Ti3C2Tx MXene freestanding films through drop-casting onto hydrophobic plastic substrates. Freestanding MXene films prepared using the drop-casting method can be fabricated in large areas (>125 cm2) and thicknesses (23.2 μm), and have smooth surfaces (14 nm RMS roughness) while maintaining high electrical conductivity (~7,000 S cm−1). Moreover, these MXene films can be micropatterned in three dimensions by processing on commercially available microstructured plastics, resulting in a 38% increase in normalized electromagnetic interference shielding efficiency compared with flat films. The results presented here suggest a scalable path toward creating MXene freestanding films for prototypes and industrialization.