Proton conductors operating in a high temperature range (over 200 degrees C) have attracted much interest. The promising candidates for inorganic composite membranes for proton exchange membrane fuel cells (PEMFCs) using solid SnP2O7 and SnP2O7/GO at temperatures between 150 degrees C and 250 degrees C are reported. Graphite oxide (GO) incorporated with SnP2O7 improves the proton conductivity and reduces the crossover. The structure and phase stability of the membranes are analysed by X-ray diffraction and thermos-gravimetric analysis (TGA), and the microstructure morphology is analysed by scanning electron microscopy (SEM). The SnP2O7/GO composite electrolyte exhibits the proton conductivities of 0.0076 cm(-1) at 225 degrees C and a peak power density of 18 mW cm(-2) at 220 degrees C. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.