Influence of phosphotungstic acid in sulfonated poly (ether ether ketone)/poly (amide imide) based proton conductive membranes and its impact on the electrochemical studies of microbial fuel cell application

The present work deals with the effect of phosphotungstic acid (PWA) in the sulfonated poly (ether ether ketone) (SPEEK)/poly amide imide (PAI) polymer matrices. These membranes are prepared using solvent casting method. The complexation and structural analysis are characterized by FTIR and XRD studies respectively. The obtained results of ion exchange capacity, water uptake, and proton conductivity show their physico-chemical properties of the prepared composite membranes significantly enhanced after the incorporation of PWA. At ambient temperature, 5.6 × 10−2 S/cm is the maximum conductivity achieved for the 20 wt% PWA-doped SPEEK/PAI membrane. The TGA/DTG thermograms show that the membrane retains good thermal stability with 54–57% of char yield which having maximum proton conductivity at different temperatures in the range of about 10−2 S/cm because of the Keggin unit structure of PWA. The SEM micrograph reveals the dispersion of PWA in the SPEEK/PAI matrices. The insertion of PWA in the SPEEK/PAI matrix exhibiting better properties with Bacillus amyloliquefaciens is used to carry out the performances in the microbial fuel cell for bioelectricity generation. The maximum obtained voltage and power density are 786 mV and 113 mW/m2, respectively, with current density of 207 mA/m2.