In this study, a nanocomposite graphene oxide (GO) incorporated poly (dimethyl siloxane) (PDMS) membrane was produced and used for the purification of hydrogen (H-2) by separating the (CO2). The produced membrane was characterized and the single-gas permeability test was performed. Effects of GO addition, trans-membrane pressure and membrane thickness on the gas separation performance of membrane were evaluated as a function of permeability and CO2/H-2 selectivity. GO addition increased the CO2/H-2 selectivity and H-2 purification performance. The highest CO2 permeability of 3670 Barrer and CO2/H-2 selectivity of 11.7 were obtained when the GO loading was 0.5 wt% when the trans membrane pressure was 0.2 Mpa. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.