Impact of Substrate Outgassing on the Growth of Carbon Nanotubes Using the Single-Pulse Discharge Method

Abstract EN

Carbon nanotubes (CNTs) were fabricated in air using the electrical discharge machining method.

The main parameters for this process were substrate temperature, peak current ( I p ), and pulse duration (τ).

The substrate was baked at 50°C and this temperature was maintained for 12 h under vacuum chamber; it was then cooled to room temperature and stored in vacuum for outgassing.

During single-pulse discharge in air, the substrate was heated from room temperature to the test temperatures (50 and 70°C).

The results indicated that the length, density, and purity of CNTs grown on outgassed substrates were better than those of CNTs grown without outgassing.

Additionally, CNTs grown with I p = 3 A and τ = 1200 μs were of better quality than those grown with other combinations of parameters.

The size of the discharge pit was effectively reduced by 30% (80 μm).

This finding may help in controlling the amount of peak current used during the process, thereby reducing the problems of heat-affected zones and electrode consumption.

Consequently, there was substantial improvement in the zonal selectivity and reticular density of the CNTs grown using the single-pulse discharge method.