Metal-organic framework-derived CoSn/NC nanocubes as absorbers for electromagnetic wave attenuation

Metal-organic framework-derived composites have been widely used in electromagnetic wave(EMW)absorption,but the traditional synthetic strategy greatly limits the structure and species of MOFs.This research provided a solvent-free method to synthesize Co-MOF and its derivatives.Using CoSnO_(3)as the precursor,the preparation of Co-MOF is achieved by bridging the cobalt(II)ion of CoSnO_(3)and the 2-methylimidazole skeleton.The CoSn/N-doped carbon(CoSn/NC)composites derived from CoSnO_(3)-MOF(Co-MOF with CoSnO_(3)as Co source)retain the original morphology of CoSnO_(3).Besides,the polarization effect produced by the N-doped carbon layers also benefits the excellent EMW absorption performance of the CoSn/NC composites.It is reflected in the minimum reflection loss(RL)of-48.2 dB at 2.2 mm and the effective bandwidth(EBA)of 5.84 GHz.This work provides a new channel to the construction of Co-MOFs,which could be extended to other Co-based oxides and vastly expand the species of MOFs based on metallic Co.