Water-Assisted Highly Efficient Synthesis of Single-Walled Carbon Nanotubes Forests from Colloidal Nanoparticle Catalysts

Abstract

Highly efficient single-walled carbon nanotube (SWNT) growth from Fe-Mo nanoparticle catalysts made by colloidal synthesis is demonstrated by water-assisted chemical vapor deposition. In a 10 min growth time, SWNT forests with heights up to 1.5 mm were synthesized possessing a 2.8 nm average diameter, carbon purity above 99.99%, and Brunauer-Emmett-Teller (BET) surface area of 1200 m 2 /g, which rivals SWNTs grown from sputtered Fe thin films. Realization of high efficiency SWNT growth using catalysts prepared by economical and scalable wet processes opens up a cost-effective route toward the mass production of SWNT forests.

Systematic Conversion of Single Walled Carbon Nanotubes into n-type Thermoelectric Materials by Molecular Dopants

“…The present SWNTs showed ~ 0.15 eV of band gap energy (Figure S3)293031, which agrees with the shift of work function after the n-type doping. A similar energy shift derived from the n-type doping was predicted by theoretical calculations3233 and experimentally observed for potassium-doped SWNTs34.…”

Stable colloidal Co–Pd nanocatalysts for carbon nanotube growth

“…The catalyst is often deposited on the surface as a thin film and then transformed into catalytically active nanoparticles by heating. On the other hand, liquids 1, 2 or colloidal nanoparticles are valuable catalyst precursors 3, 4, as they can be applied to many surfaces with uneven geometries such as meshes and 3D matrices 5. They also allow patterning at low cost over large areas on flat surfaces by methods such as nanoimprinting 6.…”

Synthesis of vertically-aligned CNT arrays from diameter-controlled Fe₃O₄ nanoparticles

“…This suggests that when the particles are sintered, they coalesce to form larger particles, in which more than one particle layer is present, and/or that the lateral spatial distribution is nonuniform. 22) Sintering and ripening effects would be expected to take place if there are multiple layers of particles, and larger catalyst particles would then produce CNTs with larger diameters than those of the original or parent catalyst particles. 23) Raman spectra were carried out to characterize the quality of the synthesized VACNTs, as shown in Fig.…”