Hollow silicon carbide nanoparticles from a non-thermal plasma process

Abstract

We demonstrate the synthesis of hollow silicon carbide nanoparticles via a two-step process involving the non-thermal plasma synthesis of silicon nanoparticles, followed by their in-flight carbonization, also initiated by a non-thermal plasma. Simple geometric considerations associated with the expansion of the silicon lattice upon carbonization, in combination of the spherical geometry of the system, explain the formation of hollow nanostructures. This is in contrast with previous reports that justify the formation of hollow particles by means of out-diffusion of the core element, i.e., by the Kirkendall nanoscale effect. A theoretical analysis of the diffusion kinetics indicates that interaction with the ionized gas induces significant nanoparticle heating, allowing for the fast transport of carbon into the silicon particle and for the subsequent nucleation of the beta-silicon carbide phase. This work confirms the potential of non-thermal plasma processes for the synthesis of nanostructures composed of high-melting point materials, and suggests that such processes can be tuned to achieve morphological control. V C 2015 AIP Publishing LLC.

Dissociation of tetramethylsilane for the growth of SiC nanocrystals by atmospheric pressure microplasma

“…[ 1–3 ] Microplasmas key features allow for the synthesis of ultrasmall nanoparticles and quantum dots with compositions that are most often complementary to low‐pressure plasma processes. However, while low‐pressure plasmas have been subject of extensive studies, [ 3–11 ] little is known about the formation mechanisms of nanoparticles in atmospheric pressure plasmas and diagnostic experimental results are limited. [ 1,12,13 ] In this contribution, we have studied the concentration of species at the exit of a microplasma by mass spectrometry of residual gases.…”

Plasmonic Core–Shell Silicon Carbide–Graphene Nanoparticles

“…The material discussed here was produced by a nanoparticle synthesis reactor very similar to the one previously reported by our group. 13 It is comprised of two continuous flow capacitively coupled nonthermal plasma reactors placed in series. A photograph of the reactor is shown in Figure S1 of the Supporting Information.…”

“…12 For the process used for this study, silicon nanoparticles produced in a first nonthermal plasma stage are rapidly carbonized by a second nonthermal plasma into β-phase silicon carbide nanoparticles. 13 By carefully controlling the carbon precursor concentration, it is possible to tune between bare silicon carbide, single layer, and few layers of graphene coating. Fourier transform infrared (FTIR) measurements show a broad absorption feature in the infrared region that we attribute to plasmon-induced resonance.…”

Gas‐Phase Plasma Synthesis of Free‐Standing Silicon Nanoparticles for Future Energy Applications

“…Mangolini et al reported the processing rate of non‐thermal plasma as 14.4 mg h −1 for small Si‐NPs with sizes of 2–4 nm, and as 52 mg h −1 for larger Si‐NPs. Apart from Si‐NPs, non‐thermal plasmas are suitable for synthesizing other nanomaterials such as Ge‐NPs, SiGe‐NPs, and SiC‐NPs …”