Gas sensing property of graphene oxide and its thermal reduction products on CH_4 and H_2 gases

Graphene oxide(GOS)was prepared by graphite oxide(GO)which was prepared by the Hummers method,then roasted the GOS under different temperatures to get different reduction degrees of graphene oxide(RGOS).Structure,functional groups,and surface topography of the samples were carried out by AFM,XRD,XPS,and SEM.The GOS and RGOS gas sensors were then fabricated by coating method.Results show that the Graphene oxide thickness is 1.08-1.72 nm,for single or double GOS.When graphene oxide was reduced from 100 to 250 ℃,the basal spacing of the samples were decreasing from 8.87 to 3.68nm;With the increasing of the reduction degrees,the O/C atomic ratio was decreasing from 0.43 to 0.32,showed that the oxygencontaining functional groups were gradually reduced and the C-OH functional group was decreased obviously,the gas sensitivity was also decreased.Graphene oxide and its lower reduced products show a good sensitivity to CH4 and H2gas.The GOS sensor had a best sensitivity to CH4 and H2gas which can reach 81% and 77.2%,respectively.