Effect of heat treatment on microwave absorption properties of Ti3C2Tx

Ti3C2Tx MXene with good thermal conductivity and microwave absorption (MA) properties is an attractive candidate used in 5G communication applications to dissipate the accumulated heat and absorb electromagnetic energy. Ti3C2Tx has good MA properties partially due to the contribution of the polarization loss induced by the surface terminations; however, these terminations, especially the −F, are easily removed under thermal environment. To investigate the influence of the annealing conditions on the MA properties, Ti3C2Tx was vacuum-annealed at 150, 350, and 550 °C, respectively, for 1 h. The 150 °C-annealed Ti3C2Tx demonstrated the best reflection loss (RL) value of − 15.10 dB at 9.92 GHz as compared with the pristine Ti3C2Tx (− 11.07 dB at 7.92 GHz) and resultant products annealed at 350 °C (− 3.60 dB at 13.68 GHz) and 550 °C (− 4.97 dB at 11.28 GHz). Annealing at 150 °C for 1 h removed part of −F, but tuned the impedance matching of Ti3C2Tx, thus improving the MA properties. Further prolonging the annealing time from 1 to 4 h at 150 °C induced a slight deterioration on the MA properties mainly due to −F desorption. This work confirms the application temperature of Ti3C2Tx as an attractive MA material used in 5G communication.