Molybdenum blue preassembly strategy to design bimetallic Fe0.54Mo0.73/Mo2C@C for tuneable and low-frequency electromagnetic wave absorption

Abstract

Advanced electromagnetic wave absorption nanomaterials can play an important role in addressing the issue of increasing electromagnetic pollution in the wireless communication field. Herein, a series of coralloid bimetallic Fe_0.54Mo_0.73/Mo₂C@C (FMC) composites synthesized by a molybdenum blue preassembly strategy is presented as low-frequency electromagnetic wave absorbers with tunable frequency for the first time. Molybdenum blue, an ideal platform for molecular preassembly, retained abundant interfaces during the process of transformation in a confined space and promoted interfacial polarization, while bimetallic Fe_0.54Mo_0.73 particles significantly improved the electromagnetic wave absorption properties of Mo₂C@C (MC). The minimum reflection loss (RL) continuously moved from a high-frequency region (Ku band) to a low-frequency region (S band) as the content of Fe_0.54Mo_0.73 particles increased. The optimized FMC-5 exhibited an excellent electromagnetic wave absorption performance with a minimum RL value of −48.91 dB at 4.08 GHz. This work not only provides a deeper insight into designing high-performance electromagnetic wave absorbers with tunable frequency, but also offers a framework for the exploration of preparing polyoxometalate-functionalized derivative materials by a preassembly strategy.