Multifunctional MnFeO/TiO/TiCT composites based on in-situ grown TiO for efficient microwave absorption, high hydrophobicity, and heat dissipation properties.

Despite the fact that the 2D structure TiCT with abundant defects and functional groups contributes to the high microwave absorption (MA) performance, it is difficulty to improve the strength and bandwidth by pursuing higher conductivity or loading more groups due to the limitation of intrinsic properties. Therefore, it is important to ingeniously design efficient TiCT based MA composites assembling the features of abundant surface groups, good dispersibility, multiple composition, and precise structure. Inspired by the fact that TiCT contains thermodynamically metastable marginal Ti atoms, TiO nanoparticles can be grown in-situ on TiCT nanosheets uniformly and increase the spacing of TiCT layers, and then MnFeO nanoparticles are introduced into the layers of TiCT by electrostatic self-assembly method for optimized impedance matching. This designed hierarchical MnFeO/TiO/TiCT composites shows excellent MA performance, and the minimum reflection loss (RL) reaches -46.91 dB with a thickness of 2.5 mm at frequency of 10.4 GHz. The high MA performance mainly comes from the enhanced interfacial polarization induced by edges location and interface region among TiO, MnFeO, and TiCT. In addition, the conduction loss existed in the interior untreated TiCT, the dielectric loss generated by multiple composition, the multiple scattering from improved large surface specific area all contribute to the excellent MA performance. Meanwhile, the simple preparation process and good stability storage at room temperature under air atmosphere of the MnFeO/TiO/TiCT composites promote its exploration on practical use, and the lab-gown cloth coated with MnFeO/TiO/TiCT composites shows better electromagnetic shielding properties, hydrophobicity, and heat transfer ability than pure fabric, showing the potential for practical application.