MXene/Co3O4 composite material: Stable synthesis and its enhanced broadband microwave absorption

Abstract

Abstract Microwave absorbers serve the purpose to ensure the transmission efficiency and accuracy in 5G telecommunications. Two-dimensional MXene has great potential in absorbing microwave. In this study, MXene(Ti3C2Tx)/Co3O4 composites are successfully fabricated by a facile and stable hydrothermal treatment in concentrated strong base and Argon environment, followed by a one-step annealing process. Phase composition, chemical state of elements, morphology and structure of the new composite materials are studied by systematical characterization. It is revealed that adsorbed Na+ ions and terminations, which are generated at the interface during hydrothermal treatment in concentrated NaOH solution, can protect the Ti3C2Tx from being decomposed. The synthesis mechanism is also proposed for stable fabrication of other MXene-based composite materials. The MXene/Co3O4 composite is able to perform single-band absorption, multiband absorption and even broadband absorption in 2–18 GHz band by tuning its composition and thickness. Particularly, better than 90% absorption in a wide range of 10.8–17 GHz can be achieved with a thickness of just 2 mm. Enhanced wideband absorption originates from the multilayer structure, the surface defects, the conductivity of Ti3C2Tx and the capacitance structure of Co3O4. Ultrathin and broadband high absorption features make the material a promising candidate for future application.