Oukrit ThonganantakulSira SrinivesWeerawut ChaiwatKonrat KerdnaweeKomkrit SuttiponparnitTawatchai CharinpanitkulPTT Public Company LimitedChulalongkorn UniversityMahidol UniversityResearch Network of NANOTEC-KU on Nanocatalyst and Nanomaterials for Sustainable Energy and Environment2020-03-262020-03-262020-01-01Catalysis Today. (2020)092058612-s2.0-85078526848https://repository.li.mahidol.ac.th/handle/20.500.14594/53635© 2020 Elsevier B.V. Iron oxide embedded on graphene oxide (Fe2O3/GO) was prepared by chemical exfoliation followed by wet impregnation. Reduced Fe2O3/GO could be employed as catalyst for synthesizing carbon nanotubes CNTs via catalytic chemical vapor deposition CCVD of n-hexane within a temperature range of 700-1000 °C. It was found that during the synthesis process, pretreatment affected the transformation of iron nanoparticles in the Fe2O3/GO, leading to significant difference in formation of carbon nanoparticles. When the Fe2O3/GO was employed within a temperature range of 700−900 °C, Fe2O3 was reduced to α-Fe, yielding CNT growth on the graphene surface. However, the α-Fe could be transformed to γ-Fe when the Fe2O3/GO was subject to the temperature of 1000 °C, resulting in formation of carbon spheres instead of CNTs. After experimentally verified, conceptual scenarios of CNT/graphene hybrid material formation with respect to the pretreatment and synthesis temperature were proposed and discussed.Mahidol UniversityChemical EngineeringChemistryArticleSCOPUS10.1016/j.cattod.2020.01.016