Amorphous solid

Arc (geometry)

Direct current

Voltage

Composite number

Engineering

Materials science

Graphene

Buffer gas

Silicon

Carbon fibers

Chemical engineering

Shielding gas

Current (fluid)

Physical chemistry

Argon

Mechanical engineering

Laser

Physics

Nanotechnology

Organic chemistry

Optics

Heat-affected zone

Microstructure

Carbon arc welding

Composite material

Nanomaterials

Chemistry

Electrode

Electric arc

Fullerene

Optoelectronics

Dangling bond

Electrical engineering

Amorphous carbon

Carbon

A direct current (DC) has been applied to prepare many carbon nanomaterials, including fullerene, graphene, and carbon nanohorns (CNHs) from inner wall of chamber. However, the growth mechanism of these carbon nanomaterials is not clear. Amorphous spherical carbon nanoparticles (SCNs), the typical ‘dahlia-like’ CNHs, and graphene with the layer numbers of 2–5 were synthesized controllably from the inner wall of the chamber by DC arc discharge method using argon, nitrogen, and hydrogen as buffer gas. Simultaneously, the effect of buffer gas pressure on the morphology of carbon nanomaterials was investigated systematically. Furthermore, the formation mechanism of these carbon nanomaterials by DC arc discharge was also investigated. Given that argon atom was difficult to bond with the carbon cluster, the random bond between carbon clusters contributed to combine into amorphous SCNs; the CN bond was the key factor in the formation of CNHs, and hydrogen contributes to form graphene sheets by terminating carbon dangling bonds. With increasing the pressure of buffer gas, intense quenching resulted in formation of carbon nanomaterials with high purity. The study on the growth mechanism of carbon nanomaterials in the inner wall of chamber promotes the preparation of carbon nanomaterials controllable by arc discharge method.

Controllable synthesis of carbon nanomaterials by direct current arc discharge from the inner wall of the chamber