A NiCo alloy nanoarray foam with an oriented structure for high-performance electromagnetic interference shielding

Nickel-based metal composites are highly promising candidates in the field of electromagnetic interference (EMI) shielding. However, the preparation of nickel-based EMI shielding materials that combine low reflection and high absorption characteristics still faces significant challenges. This study reports a rapid one-step method for preparing magnetic nickel–cobalt (NiCo) array foam with an oriented arrangement strategy, which involves the magnetic field-induced chemical deposition of nickel–cobalt nanoparticles to form a directional structure. Thanks to this oriented structure, the prepared NiCo array foam exhibits ultra-high electromagnetic shielding effectiveness (>70 dB) over an ultra-wideband (18–26.5 GHz) range. Additionally, this magnetic field-induced orientation strategy is equally applicable to other unitary or binary systems, which also demonstrate excellent electromagnetic shielding performance. This research provides new ideas and methods for the structural design of nickel-based metal materials in the field of EMI shielding.