Chemical vapor deposition of carbon nanotubes on monolayer graphene substrates: reduced etching via suppressed catalytic hydrogenation using C2H4

TL;DR

This study demonstrates a method for growing carbon nanotubes on graphene using C2H4, which suppresses graphene etching and preserves the substrate's integrity during CNT synthesis.

Contribution

The paper introduces a C2H4-based growth process that reduces graphene damage by suppressing catalytic hydrogenation, enabling high-quality graphene-CNT hybrids.

Findings

C2H4 growth suppresses graphene etching

Low-temperature growth preserves graphene integrity

Enhanced quality of graphene-CNT hybrids

Abstract

In most envisioned applications, full utilization of a graphene-carbon nanotube (CNT) construct requires maintaining the integrity of the graphene layer during the CNT growth step. In this work, we exhibit an approach towards controlled CNT growth atop graphene substrates where the reaction equilibrium between source hydrocarbon decomposition and carbon saturation into and precipitation from the catalyst nanoparticles shifts towards CNT growth rather than graphene consumption. By utilizing C2H4 feedstock, we demonstrate that the low temperature growth permissible with this gas suppresses undesirable catalytic hydrogenation and dramatically reduces the etching of the graphene layer to exhibit graphene-CNT hybrids with continuous, undamaged structures.