Controllable synthesis of Ni/NiO@porous carbon hybrid composites towards remarkable electromagnetic wave absorption and wide absorption bandwidth

The reasonable design of the composition of the composite materials is of great significance to optimized the electromagnetic (EM) wave absorption performance. Herein, the Ni/NiO@C hybrid composites with tunable Ni proportion were successfully synthesized through a two-step process. With the assistance of X-ray diffraction with refinement treatment, the specific proportion of Ni of as-obtained hybrid composites could be obtained. Employing controlling calcination time to adjust the Ni content of Ni/NiO@C hybrid composites, it has been found that the composite carbonized at 500 degrees C exhibited remarkable EM wave absorption with the minimum reflection loss (RLmin) of -49.1 dB at 4.9 mm and the widest effective absorption bandwidth (EAB(max)) of 4.56 GHz at 2.1 mm. Moreover, by adjusting the Ni source, the optimal EM wave absorption performance could be achieved. Results illustrated that the N3PC with the Ni proportion of 13.17 % showed the RLmin as low as -51.1 dB at 2.4 mm and the EAB(max) was 5.12 GHz at 2.7 mm. It is worth noting that this work demonstrates the relevance of the composition and EM wave absorption performance of hybrid composites, which offers a feasible reference for the absorption mechanism of absorber. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The study successfully synthesized Ni/NiO@C hybrid composites with tunable Ni proportion through a two-step process. By controlling the calcination time and adjusting the Ni source, the optimal electromagnetic wave absorption performance was achieved, providing a feasible reference for the absorption mechanism of absorbers.