Synthesis of carbon nanotubes on activated carbon using a metal-free NaCl catalyst: a novel and green approach

Despite the fact that numerous viable CNT techniques have been established over the last few decades, the metal-free synthesis strategy has not been substantially examined. The current work addresses the utilization of activated carbon (AC) as a supporting substrate combined with NaCl as a green catalyst for the synthesis of carbon nanotubes (CNTs) via a catalyzed chemical vapor deposition (cCVD) method. The effect of different AC–NaCl ratios (1:0, 1:1, 1:2, and 1:3) on CNT growth was investigated. The nano-particle yield was estimated and samples were characterized by BET, Electron microscopy (SEM and TEM), XRD, FTIR, and TGA analyses. The asymmetrical porous structure and high surface area of the AC clearly offer excellent uniform NaCl dispersion properties on the surface, resulting in a high catalyst–transition metal-free yield of CNTs forest growth. The results showed higher mass yield in the order AC–NaCl 1:2 > AC–NaCl 1:1 > AC–NaCl 1:3 ratio. AC and NaCl are excellent choices as substrate and catalyst combinations for the synthesis of metal-free MWCNTs as they are cost-effective and environmentally friendly.