▎ 摘　　要

Carbon solubility in the catalyst for the growth of graphene-type nanomaterials is an essential issue for their large-scale fabrication. Iron compounds are fundamental catalysts for the synthesis of carbon materials. The carbon solubility of ferrite (alpha-Fe) is similar to 0.1% at 700 degrees C, which is enough to promote the growth of graphene nanomaterials. In this work, we synthesized crystalline multilayer graphene flakes (MLGFs) by a two-step cat-alytic chemical vapor deposition method using an alpha-Fe catalyst derived from the reduction of nanostructured hematite at 950 degrees C under an Ar-H-2 environment. In the first step, nitrogen-doped multi-walled carbon nanotubes were synthesized by a benzylamine-ferrocene mixture at 850 degrees C and oxidized at 620 degrees C in air. In the second step, the reduced nanostructured hematite was exposed to a mixture of a 1:9 benzylamine-1,2-dichlorobenzene at 950 degrees C. Raman spectroscopy confirmed the presence of MLGFs with a G band and a significant 2D band intensity. The results of the thermogravimetric analysis show that the maximum oxidation rate was at 643.5 degrees C. Additional functional density calculations were performed considering graphene growth on the oriented (110) alpha-Fe surface. This work reasserts the possibility of using alternative carbon sources for graphene growth.