Fine-tuning the electromagnetic parameters of 2D conjugated metal-organic framework semiconductors for anti-electromagnetic interference in the Ku band

To address the electromagnetic interference (EMI), carbon-based composites, including metal-organic framework (MOF)-derived ones, have been proposed as electromagnetic (EM) wave absorbers. Inspired by the design principles of these materials, we provide pristine 2D conjugated MOFs (2D c-MOFs) as the alternative absorbers, without carbonization or hybridization. Beyond controlling the EM parameters of Cu3(HTTP)2 (2,3,6,7,10,11hexahydroxytriphenylene, HHTP), a 2D c-MOF, at the material level through regulating its mass ratio, we also fine-tune such parameters at the atom level by altering the metal center. Due to the improved dielectric loss, remarkably enhanced EM wave absorption is available among another three isostructural 2D c-MOFs M3(HTTP)2 (M = Zn, Ni, or Co). The strongest EM absorption of them can also be tuned from the C band to the X band and Ku band by adjusting the metal center. Co3(HHTP)2 has the best EM wave absorption, with a minimum reflection loss of -60.6 dB (99.9999% of absorption), and could against EMI in most of the Ku band (89%) which is wildly used in satellite communication, owing to the good impedance matching, and multiple loss mechanisms.