Catalytic chemical vapor deposition (CCVD) or simply CVD with variants like thermal and plasma-assisted is the dominant commercial technique for the fabrication of VGCF and VGCNF. Here, gas-phase molecules are decomposed at high temperatures and carbon is deposited in the presence of a transition metal catalyst on a substrate where subsequent growth of the fiber around the catalyst particles is realized. In general, this process involves separate stages such as gas decomposition, carbon deposition, fiber growth, fiber thickening, graphitization, and purification and results in hollow fibers. The nanofiber diameter depends on the catalyst size. The CVD process for the fabrication of VGCF generally falls into two categories: 1) fixed-catalyst process (batch), and 2) floating-catalyst process (continuous).