The most effective method for synthesizing carbon nanotubes is Chemical Vapor Deposition CVD . In this process, a substrate, usually a metal catalyst such as iron, nickel, or cobalt, is heated to high temperatures typically around 700-900C . A carbon-containing gas, such as methane, ethylene, or acetylene, is then introduced into the reaction chamber. The carbon atoms in the gas decompose and reassemble on the catalyst surface, forming carbon nanotubes.CVD is considered the most effective method for synthesizing carbon nanotubes due to its scalability, controllability, and ability to produce high-quality nanotubes with fewer defects. Additionally, CVD allows for the growth of carbon nanotubes with specific properties, such as diameter and chirality, by adjusting the reaction conditions and catalysts used.