Carbon Nanotubes Grown Using Solid Polymer Chemical Vapor Deposition in a Fluidized Bed Reactor with Iron(III) Nitrate, Iron(III) Chloride and Nickel(II) Chloride Catalysts

In this study, multi-walled carbon nanotubes (MW-CNT) were successfully synthesized using a chemical vapor deposition-fluidized bed (CVD-FB), with 10% hydrogen and 90% argon by volume, and a reaction temperature between 750 and 850 °C in a specially designed three-stage reactor. A solid state of polyethylene (PE) was used as a carbon source and iron(III) nitrate, iron(III) chloride, and nickel(II) chloride were used as catalysts. Scanning and transmission electron microscopy and Raman spectrum analysis were used to analyze and examine the morphology and characteristics of the CNTs. A thermogravimetric analyzer was used to determine the purification temperature for the CNTs. Experimental results showed that the synthesis with iron-based catalysts produced more carbon filaments. Nickel(II) chloride catalysis resulted in the synthesis of symmetrical MW-CNTs with diameters between 30 and 40 nanometers. This catalyst produced the best graphitization level (ID/IG) with a value of 0.89. Excessively large particle size catalysts do not cluster carbon effectively enough to grow CNTs and this is the main reason for the appearance of carbon filaments.