Bimetallic MOF@bacterial cellulose derived carbon aerogel for efficient electromagnetic wave absorption

With bacterial cellulose (BC) as the skeleton, bimetallic CoZn-MOF (bi-MOF) was integrated into BC networks through an in situ growth approach. After carbonization at 600 °C, a highly porous, lightweight, conductive, compressible, and hydrophobic aerogel was obtained. Characterization results revealed that the MOF-derived magnetic Co/ZnO species are inlaid in the carbon matrix and dispersed uniformly. As-prepared composite aerogels were investigated for electromagnetic wave absorption. The optimized CZn-2 sample presented a total shielding effectiveness (SET) of 46.5 dB (X band, 8.2–12.4 GHz) at a thickness of 3 mm. The absorption shielding effectiveness (SEA) and the absorption proportion were determined to be 45.9 dB and 98.7%, respectively. The superior performance was attributed to the synergy of the conduction loss and magnetic loss, as well as the unique porous structure of aerogel. The hybrid aerogel also had an efficient electrothermal response, enabling its normal function in cold conditions. Moreover, the hybrid aerogel can be processed into a sensitive sensor for strain monitoring and displayed a high sensitivity for various human movements.