In-situ derive hierarchical Ti3C2@C@ZnO heterointerface for electromagnetic absorption enhancement

Heterointerfaces formed by the intimate connection of different materials with electromagnetic losses are expected to achieve stronger electromagnetic (EM) absorption. However, constructing composites with heterointerfaces still faces great challenges in facile preparation process, optimized impedance matching, high reflection loss (RL), and ultrathin matching thickness. In this work, we develop ZIF-8 functionalized MXene to produce hierarchical Ti3C2@C@ZnO composites with heterointerface to advance EM absorption enhancement. Modified with polydopamine (PDA), few-layer Ti3C2Tx MXene sheets enable adsorption of Zn2+ metal ions on Ti3C2Tx@PDA by electrostatic interaction for in-situ growth of ZIF-8. Ti3C2iCiZnO heterointerface were obtained after heat treatment of Ti3C2Tx@PDA@ZIF-8 nanocomposites at various temperatures. The Ti3C2iCiZnO-600 degrees C with 1.15 mm thickness have a R L of -50.241 dB and an effective absorption bandwidth of 3.50 GHz. In-depth studies on the electromagnetic loss mechanisms reveal that Ti3C2, carbon, and ZnO in nanocomposites generate multiple interfacial polarization losses beyond partial conductivity losses caused by Ti3C2 and ZnO. Oxygen vacancy defects in ZnO form dipole losses with carbon. This work not only provides a simple and effective concept for preparing MXene@MOFs heterogeneous composites as an ultrathin and strong electromagnetic wave absorber, but also offers a vital guideline to fabricate various metal oxides derived from the MXene and metal-organic frameworks (MOFs) precursors.