Self-Assembled\nSandwich-like MXene-Derived Nanocomposites for Enhanced Electromagnetic\nWave Absorption

Abstract

Sandwich-like MXene/Fe₃O₄ and C/TiO₂/α-Fe two-dimensional\n(2D) nanocomposites were fabricated via in situ hydrothermal assembly\nof Fe₃O₄ nanoparticles on MXene nanosheets and\npostannealing. The as-prepared sandwich-like MXene/Fe₃O₄ nanocomposites contain uniformly distributed Fe₃O₄ nanoparticles between the interlayers of the 2D MXene\nTi₃C₂T<i>_x</i> nanoflakes.\nThe redox reaction, Ti₃C₂T<i>_x</i> + Fe₃O₄ → 3TiO₂ + 2C + 3Fe, has also been reported for the first time to transform\nthe binary MXene/Fe₃O₄ nanocomposites into ternary\nC/TiO₂/α-Fe nanocomposites with the 2D structure\nmaintained intact. Such a transition during postannealing gives rise\nto further enhanced electromagnetic wave absorption compared with\nthat of the MXene/Fe₃O₄ nanocomposites on top\nof the already improved performance of the MXene/Fe₃O₄ compared with that of pristine MXene. The 2D C/TiO₂/α-Fe nanocomposites exhibit effective absorption bandwidths\nof 3.3 and 3.5 GHz at thicknesses of 1 and 1.5 mm, respectively. This\nwork offers a new route for fabricating novel electromagnetic wave\nabsorbers, and the fine balance among lightweight, broad band, and\nsmall thickness of the C/TiO₂/α-Fe nanocomposites\nmakes them promising in the field of electromagnetic wave absorption.