Hollow engineering in CoNi@Air@C@MoS2 multicomponent composites derived from bimetallic CoNi Prussian blue analogs for ultra-wide bandwidth and strong electromagnetic wave absorption

Abstract

In recent years, two-dimensional layered transition metal dichalcogenides-based multicomponent composites (MCCs) acting as electromagnetic wave (EMW) materials have received intensive investigations. However, the vulcanication of metal greatly hindered their enhancement of EMW absorption performances (EMWAPs). Herein, a combined metal-organic frameworks-derived and hydrothermal strategy was presented to produce yolk-shell structure (YSS) CoNi@Air@C@MoS2 MCCs. The results showed that the thermal and hydrothermal treatments resulted in the generation of YSS and two-dimensional MoS2 nanosheets, which maintained the original morphology of CoNi Prussian blue analogues. The protection of thick C layer well inhibited the vulcanization of inner CoNi alloy. The formed sheet-like MoS2 further optimized impedance matching characteristics, which led to the satisfactory EMWAPs of CoNi@Air@C@MoS2 MCCs. Furthermore, the EMWAPs could be further improved by optimizing the Ni:Co atom ratios CoNi@Air@C@MoS2 MCCs, which stemmed from their boosted impedance matching performances, EMW attention and polarization loss abilities. The absorption bandwidth and reflection loss values for YSS CoNi@Air@C@MoS2 MCCs are 8 GHz and −60.83 dB, which covered almost all C-Ku bands. In general, our research work provided a valid strategy to produce YSS magnetic CoNi@Air@C@MoS2 MCCs with high efficiency, which well avoided the vulcanization of metal nanoparticles, made best of hollow engineering and atomic ratio optimization strategy to boost the comprehensive EMWAPs.