The effect of iron-carbon ratio and on carbon nanotube synthesis using camphor and ferrocene as carbon sources in the gauze reactor

Abstract

Maximizing the quantity and quality of the product is the main goal of optimizing the material manufacturing process. The use of ferrocene as a carbon source and a catalyst in carbon nanotube (CNT) synthesis results in a significant amount of impurities. The addition of camphor as an additional carbon source is a way to overcome the high Fe/C ratio in ferrocene. This study aims to add camphor carbon sources to ferrocene to obtain an optimal Fe/C ratio to reduce the product's impurities. The application of a more reliable surface response method has not been well explored in studies of optimization of CNT synthesis. In this study, the response surface method (RSM) helps exploration in the parametric study of CNT synthesis. Ferrocene (Fe(C5H5)2) has an iron-carbon (Fe/C) ratio of 46.5%. The method used is Floating Catalyst Chemical Vapor Deposition (FCCVD), using a gauze-type 316 stainless steel substrate. Variations in the ratio of Fe/C in CNT synthesis were 0%, 6.8%, and 46.5% to obtain CNT results with the best quality and quantity. The Fe/C ratio of 6.8% has the best quality and highest quantity. The results of SEM, EDS, and TEM characterization showed that CNT at the variation of the Fe/C ratio of 6.8% had a CNT outside diameter of 20–40 nm, and the percentage of carbon mass was 86.64%. The yield at this ratio is 1.608 gs from 4 gs of precursor (40.2%). The RSM analysis with the optimum conditions for CNT yield were 49 min reaction time and 16% Fe/C ratio.