Self-Assembled Sandwich-like MXene-Derived Nanocomposites for Enhanced Electromagnetic Wave Absorption

Abstract

Sandwich-like MXene/Fe₃O₄ and C/TiO₂/α-Fe two-dimensional (2D) nanocomposites were fabricated via in situ hydrothermal assembly of Fe₃O₄ nanoparticles on MXene nanosheets and postannealing. The as-prepared sandwich-like MXene/Fe₃O₄ nanocomposites contain uniformly distributed Fe₃O₄ nanoparticles between the interlayers of the 2D MXene Ti₃C₂T _x nanoflakes. The redox reaction, Ti₃C₂T _x + Fe₃O₄ → 3TiO₂ + 2C + 3Fe, has also been reported for the first time to transform the binary MXene/Fe₃O₄ nanocomposites into ternary C/TiO₂/α-Fe nanocomposites with the 2D structure maintained intact. Such a transition during postannealing gives rise to further enhanced electromagnetic wave absorption compared with that of the MXene/Fe₃O₄ nanocomposites on top of 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 of 3.3 and 3.5 GHz at thicknesses of 1 and 1.5 mm, respectively. This work offers a new route for fabricating novel electromagnetic wave absorbers, and the fine balance among lightweight, broad band, and small thickness of the C/TiO₂/α-Fe nanocomposites makes them promising in the field of electromagnetic wave absorption.