Imaging and Characterization of Ni@OLC Synthesized by Microwave‐Assisted Catalytic Methane Decomposition

Abstract

AbstractHerein, we propose a new microwave synthesis method based on a solid‐gas phase reaction. The internal structure of onion‐like carbon (OLC) containing Ni particle synthesized via the microwave‐assisted catalytic methane decomposition is characterized. Surface morphologies are tested by Raman spectroscopy and scanning electron miscroscope. Internal structural analysis is conducted using (i) scanning transmission electron microscopy with energy‐dispersive X‐ray spectroscopy (EDX) and (ii) the cross‐section processing of individual particles using a focused ion beam, followed by the analysis of the cross‐sectioned particles using field‐emission scanning electron microscopy with EDX. Consequently, the components of the synthesized particulate powder are classified into three groups: core‐shell‐structured Ni@OLC, Ni‐dispersed carbon particles, and other components. The core‐shell‐structured Ni@OLC is composed of carbon particles with predominant Ni cores. The Ni‐dispersed carbon particles comprised carbon particles with dispersed Ni and Si. These particles are considered precursors of Ni@OLC.