Synthesis of carbon nanotubes by spray pyrolysis, using a mixture of benzene and ....
Tuesday, January 6, 2015
Posted by: Lee Gomez
Synthesis of carbon nanotubes by spray pyrolysis, using a mixture of benzene and ferrocene
Multi-walled carbon nanotubes (CNT) were synthesized by the spray pyrolysis of a mixture of benzene (carbon precursor) and ferrocene (precursor for Fe catalyst) on an alumina template in a horizontal tube furnace at 900-1000°C. The concentration of ferrocene in ferrocene-benzene solution, flow rate of argon gas, and temperature were the variables studied to obtain the best reaction condition in terms of the smallness of tube diameter and unidirectionality of the nanotubes. The synthesized material was soaked in a 1:1 HCl solution plus a few drops of concentrated HNO3 in order to remove the impurity iron. Subsequently, the differential thermal (DT) and thermo gravimetric (TG) analyses of the resulting iron-free material revealed the presence of amorphous carbon in it and indicated the temperature for its removal, paving the way for the production of pure CNT. The synthesized CNT was characterized by X-ray diffraction (XRD), electron microscopy (SEM and TEM) and Raman spectroscopy. The optimum condition for the formation of nanotubes was found to be a combination of temperature of 1000°C, ferrocene (in benzene) concentration of
100 mg/ml and argon gas flow rate of 3 l/min.