Ti3C2Tx/Co-BTC derived multidimensional hierarchical Co@NC/TiO2/C nanocomposites with efficient microwave absorption

Two-dimensional (2D) transition metal carbide MXene (Ti3C2Tx) exhibits great potential in electromagnetic wave (EMW) absorbing materials due to its abundant surface functional groups and defects, tunable conductivity and high specific surface area. The Co@NC/TiO2/C composites were successfully synthesized through a solvothermal method and carbonization process using Ti3C2Tx/Co-BTC as precursor. The incorporation of magnetic metal Co nanoparticles and Rutile-TiO2 effectively addresses the issue of single loss mechanism in Ti3C2Tx. The results show that CTC-100 exhibits excellent EMW absorption performance with a minimum reflection loss (RL) value of −51.3 dB at a thickness of only 1.48 mm, and the corresponding effective absorption bandwidth is (EAB, RL < −10 dB) 4.3 GHz. Simultaneously, by adjusting the matching thickness of the material from 1.29 mm to 5.0 mm, the EAB can achieve 15.42 GHz (from 2.85 GHz to 18 GHz). The excellent EMW absorption performance of CTC-100 composite is primarily attributed to the synergistic effect of magnetic loss and dielectric loss. This study provided an effective strategy for the design of Ti3C2Tx-based EMW absorbing materials with high absorption intensity, reduced thickness, and broad effective absorption bandwidth (EAB).