ABSTRACT Achieving broadband microwave absorption requires an optimal balance between conductive loss and magnetic loss. Here, the electrical conductivity of semiconductive MOFs (Cu/AgHT‐X, X = –NH 2 , –NO 2 , and –COOH, HT = benzenethiol) is tuned with different electrophilic substituents via a Schlenk reaction, allowing for effective magnetoelectric coupling and impedance matching, thereby enhancing microwave absorption. Compared to the –COOH and –NO 2 induced semiconductive CuHT–COOH (minimum reflection loss, RL min = −4.75 dB, 5.0 mm) and CuHT‐NO 2 (RL min = −8.19 dB, 2.8 mm), an enhancement of RL min of –NH 2 (−37.72 dB, 4.5 mm) facilitates the microwave absorption. The Fe 3 O 4 /CuHT‐NH 2 composite is prepared with coupling flower‐shaped Fe 3 O 4 nanoparticles (<2 µm) and CuHT‐NH 2 . The Fe 3 O 4 /CuHT‐NH 2 ‐50% exhibits an effective absorption bandwidth (EAB) of 4.46 GHz at 1.9 mm and a RL min of −45.73 dB at a thickness of 3.8 mm at room temperature, which is higher than that of the unadulterated CuHT‐NH 2 (EAB = 2.71 GHz). By combining the magnetic losses from Fe 3 O 4 particles with the resistance losses from Cu─S bonds, the broadband microwave absorption of the composites is enhanced. This work provides fundamental material insights for developing next‐generation materials aimed at electromagnetic pollution mitigation.
Miao et al. (Thu,) studied this question.