Flexible CNT-MXene-CNT Film with Low Surface Conductance for High- and Low-Power Electromagnetic Absorption Protection

High absorption performance terahertz (THz) and GHz absorbers with low surface conductance are urgently indispensable in the application of military electromagnetic protection and multiband communication. Herein, cost-effective approaches of modified grafting and hot-pressing molding methods are proposed to construct CNT-MXene-CNT films based on a modified methyl vinyl silicone rubber (MVSR). The resultant 3 mm CNT-1.1-MXene-1.9-CNT-1.1 sample exhibits average electromagnetic interference shielding effectiveness (EMI SE) of about 29.2 dB in the range of 2–12.5 GHz and favorable EMI SE of 48.2 dB within 0.1–2.2 THz. In addition, the optimized sample also obtains excellent EMI SE of about 31.8 and 41.2 dB under the high-power test conditions in the GHz and THz bands. Besides, the CNT-1.1-MXene-1.9-CNT-1.1 sample possesses only about 1.5% overall loading content with a low surface conductivity of 2.3 μS/m. The as-prepared absorber with a low surface conductance demonstrates enormous potential in future military and civilian applications.