Graphitic spheres by pyrolyzing toluene-ferrocene-thiophene in a chemical vapor deposition experiment

Graphitic spheres were synthesized by the aerosol-assisted chemical vapor deposition method (AACVD), pyrolyzing a solution of toluene, ferrocene, and thiophene at 1020 degrees C for 30 min. The graphitic spheres were collected from different zones of the AACVD system. The scanning electron and transmission electron micrographs (SEM and TEM) showed that the synthesized carbon material comprises a complex network containing the structures of coalesced graphitic spheres structures with diameters ranging from 0.1 to 0.8 mu m. X-ray diffraction patterns of these structures revealed a slight shoulder at similar to 21 2 theta, suggesting the presence of expanded graphitic materials. We have also identified a narrow peak of around 29.3 2 theta for samples collected outside the condenser. From a deconvolution analysis, we identified a Raman band around 1179-1194 cm(-1), attributed to sp(2) and sp(3) bond stretching, indicating surface functionalization. The morphology, surface chemistry, composition, and thermal stability of graphitic spheres are discussed. Additionally, we present a density functional theory study to support the structural stability of many functional groups and chemical doping based on the elements sulfur and oxygen on curved carbon structures. The HOMO and LUMO energies and the electrostatic potential from charge density of several chemical species such as C-O-C, C-COOH, O-furan, C-SH, C-SO, C-SO2, and S-doping in a C-240 fullerene are discussed. [GRAPHICS] .

Automated summary

Graphitic spheres were synthesized using the AACVD method, with toluene, ferrocene, and thiophene as precursors. The synthesized carbon material consisted of coalesced graphitic spheres with diameters ranging from 0.1 to 0.8 μm. X-ray diffraction patterns revealed expanded graphitic materials, and a narrow peak was observed in samples collected outside the condenser. Surface functionalization was identified through Raman analysis, and the morphology, surface chemistry, composition, and thermal stability of the graphitic spheres were discussed. Density functional theory study supported the structural stability of functional groups and chemical doping on curved carbon structures.