Preparation and investigation of acid–base composite membranes with modified graphitic carbon nanosheets for direct methanol fuel cells.

The ethylenediamine‐modified graphite oxide (EGO)‐doped sulfonated poly (arylene ether ketone) (SPEEK) composite membranes have been prepared and developed for fuel cell applications in the present work. The base‐modified EGO improves the dispersion of inorganic nanosheet in the polymer matrix and enhances proton conductivity by creating continuous conduction pathways. Furthermore, the methanol barrier property also be enhanced due to the nanosheet block the methanol‐transport channels. EGO‐filled membranes display improved dimensional stability, proton conductivity, and ethanol permeability than those using SPEEK control and graphite oxide (GO)‐filled membranes. In the direct methanol fuel cells (DMFCs), the SPEEK/EGO‐1.5 membrane displays the highest current density of 395.9 mA/cm2 at 60°C, which is 1.6‐ and 1.4‐fold higher than that of SPEEK (254.0 mA/cm2) and SPEEK/GO membrane (292.6 mA/cm2). [ABSTRACT FROM AUTHOR]