Direct Synthesis of Vertically Interconnected 3-D Graphitic Nanosheets on Hemispherical Carbon Particles by Microwave Plasma CVD

High-quality, free-standing, and vertically interconnected three-dimensional (3-D) graphitic nanosheets (GNSs) were synthesized over the surface of hemispherical carbon particles/GaN at 700 °C by microwave plasma chemical vapor deposition (CVD) in presence of methane gas, whereas the hemispherical carbon particles have been directly deposited on GaN/sapphire template. The GNSs are ~1-5 nm in thickness and have a graphitic flake structure on hemispherical carbon particles. The vertically interconnected 3-D GNSs on hemispherical carbon particles have been characterized by scanning electron microscopy, transmission electron microscopy, selective area electron diffraction pattern, X-ray diffraction, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and nitrogen gas adsorption-Brunauer-Emmet-Teller. The present CVD approach is capable of producing large quantities of GNSs with high purity. Moreover, a high-purity free-standing and vertically interconnected 3-D GNSs on hemispherical carbon particles have an enormous potential for applications in electronic devices, biological sensors, gas uptake and storage, fuel cells, lithium ion batteries, and more.