Synthesis of graphene oxide-mediated high-porosity Ni/C aerogels through topological MOF deformation for enhanced electromagnetic absorption and thermal management

Magnetic metal/carbon composite aerogels with high porosity are emerging as excellent functional materials for electromagnetic (EM) attenuation and thermal management because their unique structural advantage not only intensifies EM energy consumption, but also obstructs heat conduction. Herein, we employed Ni-MOFs as a precursor, induced its topological deformation in the presence of graphene oxide (GO) nanosheets, and finally harvested composite aerogels composed of GO nanosheets and Ni-MOF fibers. It was found that GO nanosheets can resist the thermal shrinkage of composite aerogels during high-temperature pyrolysis and endow the resulting Ni/C@rGO composite aerogels (NCGCAs) with very high porosity (96.4%) and extremely low density (0.04 g cm⁻³). Electromagnetic analyses revealed that changes in structure and composition effectively reinforce the overall loss capability of NCGCAs, and thus generate obvious improvements in broadband response with a thin thickness (12.8-18.0 GHz, 1.5 mm). The good EM absorption performance of NCGCAs is significantly superior to those of many reported Ni/C aerogels. In addition, the structural advantage of NCGCAs demonstrates their potential application in thermal management. This GO-mediated MOF deformation is a promising strategy for the formation of high-porosity magnetic metal/carbon composite aerogels, which may bring some unexpected benefits in different fields.