MIL-125(Ti)-derived core-shell TiO2@C composites for tunable and efficient microwave absorption

Metal-organic framework (MOF)-derived carbon materials exhibit significant advantages for microwave absorption applications, owing to their high electrical conductivity, structural tunability, and abundant intrinsic defects and heterogeneous interfaces. However, achieving an optimal balance between magnetic and dielectric losses remains challenging for most magnetic metal-based MOFs-derived absorbers. In this study, MIL-125(Ti) was prepared as a template, and TiO 2 @C-x composites were synthesized via a two-step pyrolysis method. Experimental results demonstrate that the pyrolysis temperature significantly affects the graphitization degree of the carbon matrix and the formation of TiO 2 nanoparticles, thereby playing a dominant role in the dielectric and microwave absorption properties of the investigated MIL-125(Ti)-derived core-shell TiO 2 @C composites. Notably, the TiO 2 @C-700 composite delivers an effective absorption bandwidth of 3.2 GHz in 9.2-12.4 GHz at a thickness of 2.01 mm. Therefore, the MIL-125(Ti)-derived TiO 2 @C composites fabricated in this study establish a viable and nonmagnetic strategy for designing tunable, lightweight, and high-performance MOF-derived microwave absorbers.