CuNi alloy/ carbon foam nanohybrids as high-performance electromagnetic wave absorbers

Three-dimensional (3D) carbon foams (CF) embedded with CuNi alloy nanoparticles have been constructed for electromagnetic wave absorption application. In the synthetic procedure, Ni2+ and Cu2+ were firstly adsorbed into the melamine foam (MF) to form Ni2+-Cu2+/MF composites, which were then subject to the pyrolysis treatment, resulting in the production of mesoporous CuNi alloy/CF. The texture characterizations indicate that CuNi alloy nanoparticles whose size distribution was 20–600 nm were embedded on the surface of the CF. Other than previous carbon structures, the CuNi/CF with CuNi alloy nanoparticles evenly distributed into the 3D carbon matrix inherits the characteristic of the 3D structured N-rich MF, which induces masses of dipole polarization, interfacial polarization and electromagnetic wave scattering. The CuNi11 exhibits excellent electromagnetic wave absorption performance with the reflection loss (RL) of −50.20 dB at a thin thickness of 1.6 mm. This work highlights the effect of metal compositions on the electromagnetic wave absorption performance and provides an environmentally friendly, low cost and easy-to-large-scale-preparation approach for the design of metal alloy/CF electromagnetic wave absorbers.