Graphene synthesis via double thermal chemical vapor deposition on Ni substrate by different cycles of refined cooking palm oil

Graphene successfully formed on the Ni surface due to segregation and precipitation of high amount of carbon originated from the source material occurred at cooling process. The growth of graphene at different cycles of refined cooking palm oil using double thermal chemical vapour deposition method (DTCVD) was investigated. The samples were prepared at different cycles of refined cooking palm oil, which is unused (refined), first cycle, second cycles and third cycles at vaporization temperature of 350 °C and the temperature of Ni substrate constant at 900 °C. Comparison of the Fesem results indicated that the difference of cycles refined cooking palm oil has significant structural changes. Third cycles of refined cooking palm oil as precursor shown the graphene grain seems to growth perfectly compared to other samples. It might be attributed to the segregation of carbon onto the Ni (111) surface, whereas the graphene growth seems to be influenced by the rate of the carbon atom generation. It was found that the increment of carbon contributed to the high carbon content in cycles of refined cooking palm oil. Raman results reveal that the sample synthesis using third cycles refined cooking palm oil is weak D-peak, which indicates the low contribution of a defect structure. These reactions potentially decrease the layer stacking of graphene sheets according to the low value of defect and the higher ratio of I2D/IG = 0.3 respect to other samples.