Boosting high-performance terahertz wave shielding of MXene@BNS/SiC_w/SiOC composites by heterogeneous interface engineering and 3D-printed metastructure design

The rapid development of terahertz (THz) technology brings about the issue of electromagnetic interference (EMI) pollution. Enormous attention has been attracted to develop high-performance THz EMI shielding materials. Herein, a Ti₃C₂T_x MXene@BNS/SiC_w/SiOC composite with superior THz wave shielding performance is developed through heterogeneous interface engineering. Sucroses are grafted onto BN nanoparticles (BNSs) to enhance the interfacial interactions between the MXene and BN. Driven by hydrogen bonding, the BNS is uniformly dispersed on the layer surface of Ti₃C₂T_x. Afterward, SiC whiskers (SiC_w) are introduced to enhance heterogeneous interface engineering. The fabrication parameters are optimized through an orthogonal experimental design. The resulting bulk MXene@BNS/SiC_w/SiOC composite has a high average SE_T of 42.3 dB. Its excellent THz wave dissipation capability is attributed to the enhanced interfacial polarization from the numerous heterointerfaces, as well as conductive loss. Subsequently, four types of three-period minimal surface (TPMS) metastructures with Diamond (D), I-Wrapped Parallel (I-WP), Gyroid (G), and Primitive (P) architectures are designed and fabricated via vat photopolymerization 3D printing. Among these, the SE_T value of the developed D metastructure is improved to 68.3 dB, which is higher than that of most reported EMI shielding materials. Its special porous structure increases the internal multiple reflections of electromagnetic waves, leading to superior THz wave shielding performance. The architecture also demonstrates hydrophobicity and excellent thermal transfer capability. This work sheds new light on the development of advanced THz wave shielding materials through heterogeneous interface engineering and 3D-printed metastructure design.