The objectives of this work are to prepare and characterize poly[2,2'-m-(phenylene)-5,5'-bibenzimidazole]/graphene oxide (PBI/GO) solid electrolyte for direct alcohol alkaline fuel cell (DAAFC) applications. GO nanosheets are coated onto a FBI surface using a spin coater to construct the PBI/GO composite membrane. The PBI/GO composite membrane exhibits an ionic conductivity of 2.53 x 10(-2) S cm(-1) at 80 degrees C, which is improved by 72-93% when compared with the pure PBI membrane. In addition, the methanol permeability is reduced by 18-25% by incorporating GO onto the PBI top surface. The peak power density (P-max) of the PBI/GO electrolyte reaches 200 mW cm(-2) when using alkaline methanol as fuel with Pt-based catalysts, or 120 mW cm(-2) when fed with an ethanol and alkaline solution mixture at 80 degrees C. Replacing the Pt-based catalysts with Hypermec (TM) catalysts resulted in P-max of 40 and 100 mW cm(-2), for methanol and ethanol fuel cells, respectively. These superior DAAFC power outputs are ascribed to the improved anion conduction of the KOH doped GO and the suppressed methanol cross-over from high aspect ratio GO as the alcohol barrier layer. (C) 2017 Elsevier Ltd. All rights reserved.