Precise Catalyst Production for Carbon Nanotube Synthesis with Targeted Structure Enrichment

Abstract

The direct growth of single-walled carbon nanotubes (SWCNTs) with a narrow distribution of diameter or chirality remains elusive despite significant benefits in properties and applications. Nanoparticle catalysts are vital for SWCNT synthesis, but how to precisely manipulate their chemistry, size, concentration, and deposition remains difficult, especially within a continuous production process from the gas phase. Here, we demonstrate the preparation of W6Co7 alloyed nanoparticle catalysts with precisely tunable stoichiometry using electrospray, which remain solid state during SWCNT growth. We also demonstrate continuous production of liquid iron nanoparticles with in-line size selection. With the precise size manipulation of catalysts in the range of 1–5 nm, and a nearly monodisperse distribution (σg < 1.2), an excellent size selection of SWCNTs can be achieved. All of the presented techniques show great potential to facilitate the realization of single-chirality SWCNTs production.

Evolution Mechanism of Solid‐Phase Catalysts During Catalytic Growth of Single‐Walled Carbon Nanotubes

“…[13,21] This is because NPs with an invariant structure can provide a constant carbon (C) atom diffusion coefficient, i.e., a constant C atom diffusion pathway and nucleation site, during the nucleation stage. [13] To achieve this goal, various strategies have been proposed by researchers [24][25][26][27] ; these include the precise adjustment of the size and component of solid NPs before injection into the reaction chamber, [24,25] the development of a "Trojan" catalyst to trap the catalyst at a specific location [26,27] and selecting the different types of catalysts to precisely control the diameter distribution of SWCNT. [7] In fact, there is still a discrepancy between the ideal and experimentally obtained chirality purity of SWCNTs.…”

Recent Advances in Structure Separation of Single‐Wall Carbon Nanotubes and Their Application in Optics, Electronics, and Optoelectronics

“…Using floating CVD catalysts, Kauppinen et al realized the direct synthesis of colorful SWCNT thin films by the selective nucleation of SWCNTs. [91] Most recently, Zhang et al achieved the continuous production and sieving of refractory W-, Mo-, and Re-based nanoparticles [92] and bimetallic alloy catalysts [93] with tiny and near-monodisperse sizes, which demonstrated the significant effectiveness for obtaining a narrow chirality distribution of SWCNTs (Figure 3e). Although the structure-controlled growth of SWCNTs has made significant progress, the purity and yield of the grown SWCNTs still do not satisfy the requirements for practical applications in devices.…”