Wheat-like Ni-coated core–shell silver nanowires for effective electromagnetic wave absorption

Abstract

Nowadays, developing high-performance electromagnetic functional materials to eliminate the ever-increasing electromagnetic pollution problem is necessary for the complex electromagnetic environment. However, the materials with high electrical conductivity are prone to secondary electromagnetic pollution due to interface impedance mismatching. Herein, the wheat-like electrically conductive and magnetic silver nanowire@nickle (AgNW@Ni) composites were fabricated via a one-pot in-situ growth method. The electromagnetic properties of the composites could be regulated by adjusting different ratios of precursors, resulting in various morphological features of the nanowire as the core with different Ni shell thicknesses. When the Ag and Ni molar ratio was 1:1.1, the AgNW@Ni composite exhibited the optimal minimum reflection loss (RLmin) of −61.1 dB with an adequate effective absorption bandwidth (EAB) of 4.06 GHz owing to good impedance matching, abundant heterostructures, and synergistic electrical and magnetic losses. Even after three months, it still maintained an acceptable RLmin value of −39.7 dB and similar EAB, demonstrating its long-term operational stability. This unique composite is expected to be applied in more actual electromagnetic protection occasions.