Effect of Methane Concentration and Temperature on The Layer Number of Graphene Foam Synthesized by CVD

In this study, the few-layer graphene foam (GF) was synthesized by chemical vapor deposition (CVD) method and the effect of methane concentration and the synthesizing temperature on the number of GF layer have been studied. With methane concentration changing as 0.5, 0.6, 0.7, 1 and 1.5 sccm (standard cubic centimeters per minute) the 2, 4, 6, 11 and 25 layer graphene foam was obtained, respectively. The CVD synthesizing temperature also was studied and by changing the temperature as 900, 1000 and 1120˚C, the 23, 10 and 6 layer GF was synthesized. The images of scanning electron microscopy (SEM) showed the good quality of porous structure of synthesized GF. Raman analysis was used to confirm the formation of graphene foam and to find the relationship between the methane concentration and the synthesizing temperature (as synthesizing conditions) and layers number of GF. The obtained results from Raman analysis showed that the methane concentration and synthesizing temperature are important parameters for formation of few-layer GF. The two-layer GF was synthesized by decreasing the concentration of methane to 0.6 sccm and increasing the temperature to 1120˚C.