Graphite/nickel nanoparticle composites prepared by soft chemical methods

Abstract

The aim of this work is to obtain and characterize a composite material using an environmentally friendly matrix and green processes. To this end, different composites of as-received commercial graphite flakes (G) and nickel nanoparticles (Ni NPs) have been prepared by a one-step soft synthesis and by mechanical mixing. The properties of the composites have been compared by means of X-ray diffraction analysis, electron microscopy, Raman spectroscopy, and magnetometry. The microwave absorption behavior of the composites has also been assessed in the 0.1–3 GHz frequency range, to explore potential applications. The composites prepared by chemical synthesis followed by heat-treatment display improved crystallinity and magnetization. Small amounts of Ni NPs in the chemically synthesized composite not only enhance the microwave absorption properties of graphite, reaching values above 10 dB at 2.5 GHz, but also extend the use of graphite as a microwave absorber to low frequencies.