Multi-scale Co-MOF derived Co-N/C@graphene hybrid aerogel for effective electromagnetic wave absorption

The strategy of customizing MOF-derived electromagnetic wave (EMW) absorbing materials through the construction of precursor size has become a new research direction. While exploring the dimensional adaptability of Co-MOF derivatives in graphene hybrid aerogel for electromagnetic wave absorption is not widely researched, manipulating the compositions and microstructures of EMW absorbing materials has been found to afford superior EMW absorption. Herein, a series of Co-N/C@graphene hybrid aerogel (CNGA) were successfully synthesized by integrating graphene and multi-scale Co-MOF derivatives which are derived from multi-scale Co-MOF precursors. The results displayed the CNGA containing nanoscale Co-MOF derivatives at a 20   wt% filler ratio exhibited the optimal reflection loss (−46.8   dB, 2.7   mm) and the maximum effective absorption bandwidth (5.3   GHz, 2.1   mm). The exceptional EMW absorption properties are credited to the collaborative impact of distinctive loss mechanisms benefited from the small particle size of Co-MOF derivatives in CNGA and appropriate filler ratio. This work demonstrates the correlations between the size of Co-MOF derivatives and electromagnetic parameters of CNGA, and provides a guidance for the development of advanced hybrid aerogel electromagnetic wave absorbing materials.