**2.3. Original target preparation method**

The target was prepared by following a recipe developed by Enachescu's group [28, 31, 32]. This recipe involves the mixing of graphite cement (GC 8010-B from Metal Forming Lubricants) with metal catalysts powder (Sigma Aldrich). We have studied several target compositions using uni- as well as bi-components metal catalysts. From all the combinations the best composition for SWCNTs synthesis was found to be Co 0.6%, Ni 0.6%, and C 98.8% (atomic percentage).

The mixture was transferred into a Teflon mold (20 mm diameter) and then cured 4 h at 130°C in air to increase the mechanical strength. Further another heat treatment of the target was applied for 1 h at 800°C in inert atmosphere to remove all the remaining organic compounds.


**Table 1.** The parameters used for carbon nanomaterial synthesis.
