Synthesis and characterization of CNTs using polypropylene waste as precursor

Highlights
- A facile method for producing CNTs from polypropylene waste is proposed.
- Optimization of Ni/Mo mole ratio using RSM suggests the adequacy of cubic model.
- Process parameters were optimized by RSM using Box-Behnken four factorial design.
- Maximum desirability of one suggested that 514% of CNTs would yield over Ni4Mo0.2MgO1.
- Increase in Ni/Mo ratio from 0.5 to 20, inner diameter of CNTs decreases from 25 to 2 nm.