Preparation of MXene/BN Composites with Adjustable Microwave Absorption Performance.

The challenge of developing a high-efficiency microwave absorbent remains, because of the compatibility between microwave absorption and high-temperature-resistant performance in practical application. Herein, a facile method is used to obtain serial MXene/BN-zxy composites, where zx:y indicates the weight ratio of MXene and boron nitride (BN) in the composites, with adjustable microwave absorption performance (MAP) which can be regulated by the ratio of MXene and the BN nanosheet. In particular, the as-prepared absorbents with supercapacitance-like structure significantly enhanced the MAP and could be served more than 900 °C. The results of MAP reveal that the minimum reflection loss (RL) can reach -20.94 dB with a MXene/BN-101 composite coating thickness of 4.0 mm; the effective attenuation bandwidth (RL< -10 dB, i.e., 90% microwave energy is attenuated) is up to 9.71 GHz (7.94-17.65 GHz). From a detailed analysis, it is observed that attenuation is the critical limiting factor for MAPs rather than impedance mismatch, which can be assigned to the poor MAP of BN nanosheets. In any case, as-prepared absorbents have potential applications in the field of heating components.