Facile synthesis of a rod-like Ni/TiO2/C nanocomposite for enhanced electromagnetic wave absorption

Abstract

In this study, we utilized a simple calcination method to prepare a Ni/TiO₂/C composite, which was synchronously grown from magnetic, semiconductor, and conductive materials. XRD, SEM, Raman, and XPS characterization methods were used to analyze the crystal structure, graphitization degree, morphology size, and valence state of Ni/TiO₂/C, and its electromagnetic wave absorption performance was tested. It was revealed that rod-like Ni/TiO₂/C had good electromagnetic wave absorption performance at a thickness of 1–5.5 mm; in particular, its reflectance reached −40 dB at 3.5 mm and its absorption bandwidth (reflectivity < −10 dB) reached 4.4 GHz (6.0–10.4 GHz) at a thickness of 4.0 mm. It was thus revealed that its electromagnetic wave absorption rate and absorption bandwidth can be regulated by its thickness. Compared with Ni/TiO₂, it was proven that the conductive materials (carbon), magnetic materials (Ni), and semiconductor materials (TiO₂) in the rod-like Ni/TiO₂/C composite can synergistically absorb electromagnetic wave energy through dielectric and magnetic losses.