Novel solvothermal preparation and enhanced microwave absorption properties of Ti₃C₂T_x MXene modified by in situ coated Fe₃O₄ nanoparticles

Two-dimensional transition metal carbide/nitrides, typically represented by Ti₃C₂T_x, have been believed as a potential novel microwave absorption material because of their unique two-dimensional (2D) laminated structure, native defects and abundant surface chemistry. However, its intrinsic single dielectric loss mechanism limits the future improvement of microwave absorption properties. Herein, we report a simple solvothermal route for in situ heterogeneous nucleation and growth of Fe₃O₄ magnetic nanoparticles on the Ti₃C₂T_x MXene surface and interlayer, which is denoted as Fe₃O₄@Ti₃C₂T_x nanocomposites, thus balancing the impedance matching, introducing more loss mechanism and enhancing microwave absorption performance. Interestingly, the solvothermal process provides a reducing environment which protects Ti₃C₂T_x MXene from oxidation at temperature up to 200 °C, endowing Ti₃C₂T_x MXene a high stability compared with hydrothermal process. The sample containing 25 wt% Fe₃O₄ exhibits an impressive microwave absorption performance, the minimum RL of −57.2 dB at 15.7 GHz and an effective absorption bandwidth of 1.4 GHz (thickness 4.2 mm), which is mainly attributed to the suitable impedance matching, enhanced interface polarization and Debye relaxation caused by unique laminated heterointerface structure of Fe₃O₄@Ti₃C₂T_x. This work provides a simple and novel strategy for the modification of MXene and the development of high performance MXene based microwave absorbing materials.