Fabrication of multi-dimensional heterostructure towards highly efficient microwave absorbing performance and flame retardancy

To diminish the intimidation of the electromagnetic wave pollution, high-performance electromagnetic absorbing material are badly-needed for the normal operation of precision instruments and the people's health. A new type multi-dimensional heterostructure microwave absorber was designed by combining the carboxylated one-dimensional carbon nanotubes (CNT), two-dimensional MXene and graphene oxide (GO), then was reduced and foamed (foamed and reduced GO, F-rGO) by a simple one-pot method under hydrazine treatment to form CNT-MXene-F-rGO. For the 25 wt% CNT-MXene-F-rGO composites, the lowest RL value reached to 57.6 dB at 10.3 GHz with a thickness of 2.5 mm and an EAB of 3.3 GHz, meeting the high requirements of light, wide-band and high-efficiency. Moreover, the conduction loss, dielectric loss, multiple reflection and scattering collectively functioned to enhance the electromagnetic wave absorbing property. In addition, the heat release capacity (HRC), peak heat release rate (PHRR) and total heat release (THR) of EP/CNT-MXene-F-rGO10 composites greatly reduced by 53.0%, 40.3% and 15.6%, respectively, showing excellent flame retardancy via the nano-tunneling and catalytic carbonization effect.