Designed construction of Ti3C2Tx@PPY composites with enhanced microwave absorption performance

The unique features of 2D layered structure, native defects and abundant functional groups provide special peculiarities for exploring Ti3C2Tx MXenes in microwave absorption field. Nonetheless, both bad conductivity and poor impedance matching of Ti(3)C(2)T(x )MXenes lead to relatively poor EM absorption performance. Herein, by modifying Ti(3)C(2)T(x )MXenes with conductive PPy microspheres, a new core-shell like delaminated structure composites were fabricated for significant enhancement of absorption performance. It demonstrated that the obtained Ti3C2Tx@PPy composites showed excellent microwave absorption performance due to synergistic effect between Ti(3)C(2)T(x )and PPy microspheres. The 10 wt% Ti3C2Tx@PPy composites in wax matrix displayed a minimum reflection loss (RL) of -49.5 dB at 7.6 GHz with 3.6 mm in thickness, and the effective absorption bandwidth was 5.14 GHz from 6.44 to 11.58 GHz. The widest effective absorption bandwidth was 6.63 GHz from 8.55 to 15.18 GHz, the RL reached -42.6 dB in 12.4 GHz at only 2.7 mm matching thickness. More importantly, the composites can cover 4-18 GHz by simply adjusting matching thickness of 2-5.5 mm. The fantastic absorption performance could be ascribed to the unique properties of Ti(3)C(2)T(x )MXenes and heterojunction in Ti3C2Tx@PPy, which might be a promising material in microwave absorption applied aspects. (C) 2019 Elsevier B.V. All rights reserved.