Molecular Dynamic Simulations of the Temperature-Controlled Synthesis of High-Quality Carbon Nanotubes at High Yields

Carbon nanotubes (CNTs) are a promising functional material because of their chirality-dependent properties. However, the heat-driven exclusivity between yield and quality is a persistent challenge. High-temperature synthesis of defect-free CNTs inevitably sacrifices the yield. To address this challenge, we performed molecular dynamics (MD) studies on the growth at high temperatures and observed a mutual conversion between the lifted-off and encapsulation structures, where we have shown that the encapsulation probability is dually driven by heat and the cap size. Based on this understanding, we designed a sequential temperature control strategy, where we first nucleated the CNT at a reduced temperature to stabilize the tube–catalyst system and then heated it for defect-free growth. It achieves a nearly two-fold enhancement in the yield of defect-free CNTs in MD simulations. This work introduced deeper insight into the failure mechanism and provides guidelines for yield optimization in CNT synthesis.