Straw-bundle-like rare earth metal-organic frameworks derivatives for high-efficiency electromagnetic wave absorption

Metal-organic frameworks (MOFs) derivatives have been widely developed as electromagnetic wave (EMW) absorption materials. Nevertheless, owing to the diverse metal ions, organic ligands, and crystal morphologies of MOFs precursors, challenges still remain to overcome towards directly ascertaining the contribution of metal components on EMW absorption for precisely designing high EMW absorption performance of MOF derivatives. Here, we synthesize a series of rare earth (RE) MOF derivatives via a facile, scalable coprecipitation followed by carbonization approach. Thanks to the similar chemical property derived from lanthanide shrinkage of RE elements, the MOF-derived RE oxides (REO)/carbon (REO = CeO2, La2O3, Nd2O3) hybrids exhibit the identical straw-bundle-like microstructure, efficiently assisting the elucidation of the roles of metal components in promoting EMW absorption. Benefiting from the tunable bandgap of various REO as well as carbonization temperature, the 800 °C-carbonized CeO2/carbon shows a minimum reflection loss of − 58.7 dB at a thickness of 1.7 mm and an effective absorption bandwidth of 5.0 GHz, comparable to the best EMW absorbers. This work not only demonstrates novel, high-performance RE-MOF derivatives, but also offers a general yet efficient strategy for designing metal components to achieve high-efficiency MOF-based EMW absorbers.