Multi‐Scale Design of Metal–Organic Framework Metamaterials for Broad‐Band Microwave Absorption

Abstract

The development of nanocomposite microwave absorbers is a critical strategy for tackling electromagnetic pollution. However, challenges persist regarding material stability and achieving broadband absorption. Herein, a novel multi−scale design approach for metamaterial absorbers is proposed. First, a series of bimetallic (cobalt and copper) semiconductive metal–organic framework (SC−MOF) crystals with atomically resolved structures are successfully prepared to serve as building blocks for metamaterials. By simply adjusting the concentration ratio of the two ions, the controllable preparation of crystal morphology can be achieved. This enables to precisely tune the absorption peak and bandwidth range of the SC−MOF, resulting in excellent EMW absorption performance (effective absorption bandwidth: 6.16 GHz, minimum reflection loss: −61 dB). Based on this, printable inks are further constructed by encapsulating the SC−MOF in polydimethylsiloxane and 3D‐printed multi−layered metamaterial absorbers based on woodpile porous architecture. The metamaterial absorber demonstrates a near‐perfect absorption in the microwave spectrum (with a bandwidth of 11.33 GHz), closely matching theoretical simulations. This multi−scale design approach, combining precise MOF materials construction with topological structure design, offers new insights for the development of broadband microwave absorbers.

Ultralight Hierarchical Fe3O4/MoS2/rGO/Ti3C2Tx MXene Composite Aerogels for High-Efficiency Electromagnetic Wave Absorption

“…Electromagnetic (EM) waves serve as crucial carriers of energy in various communication technologies; however, the widespread proliferation of electronic devices and wireless communication technologies has inevitably led to EM wave pollution, which causes interference risks to precision instruments and potential threat to human health. , To tackle these problems, researchers have developed various EM wave absorption materials, including traditional magnetic materials, dielectric materials, − metal–organic frameworks (MOFs), − and carbon-based materials such as carbon nanotubes (CNTs) and carbon fiber (CF). − Recently, with the trend toward miniaturization and lightweight design in electronic and communication devices, the demand for EM wave absorbers that are ultralight, ultrathin, highly efficient, and capable of broad bandwidth absorption has intensified. This development trend renders conventional magnetic or dielectric powder and single-component carbon-based materials inadequate for practical application.…”