Tailoring Ti3C2Tx nanosheets to tune local conductive network as an environmentally friendly material for highly efficient electromagnetic interference shielding.

Environmentally friendly materials that exhibit high-performance electromagnetic interference (EMI) shielding are extremely necessary. Herein, we fabricated ultrathin Ti3C2Tx (U-Ti3C2Tx) MXene nanosheets (NS) by atomic-layer tailoring the layer thickness of Ti3C2Tx MXene. The U-Ti3C2Tx NS composites with highly efficient EMI shielding effectiveness can reduce secondary reflection, demonstrating its environmentally friendly performance. The U-Ti3C2Tx NS composite with 80 wt% loading exhibits an EMI shielding effectiveness of 58.1 dB at a thickness of 1 mm. Shielding performance analysis of different layer thicknesses shows that electron transport has an important contribution to the EMI shielding performance. Furthermore, the polarization induced by defects and terminal atoms plays an important role in the EMI shielding performance. Based on the electromagnetic (EM) wave response mechanism, a novel approach to effectively tune the EMI attenuation and shielding effectiveness can be achieved by adjusting the local conductive network. These findings will offer an effective strategy for designing environmentally friendly 2D materials with high-performance EMI shielding.

Atomic Layer Tailoring Titanium Carbide MXene To Tune Transport and Polarization for Utilization of Electromagnetic Energy beyond Solar and Chemical Energy.

The utilization of electromagnetic (EM) energy neither is affected by the weather nor produces harmful substances. How to utilize and convert EM energy is of practical concern. Herein, delaminated titanium carbide (D-Ti3C2Tx) MXene nanosheet (NS) was successfully fabricated by the modified Gogotsi's method. The choice of atomic layer processing allows tailoring of layer distance of Ti3C2Tx so as to improve polarization. High-performance EM wave absorption of D-Ti3C2Tx MXene NS composites was obtained, and their comprehensive performance is the best of all Ti3C2Tx-based composites. Due to the competition between conduction loss and polarization loss, the higher the concentration of D-Ti3C2Tx in composites, the more the conversion of EM energy to thermal energy will be. Based on the mechanism, a prototype of thermoelectric generator is designed, which can convert the EM energy into power energy effectively. This thermoelectric generator will be the energy source for low power electric devices. Our finding will provide new ideas for the utilization of EM energy.