Investigation of a cation exchange membrane comprising Sulphonated Poly Ether Ether Ketone and Sulphonated Titanium Nanotubes in Microbial Fuel Cell and preliminary insights on microbial adhesion

Abstract

Hydrothermally synthesized Titanium Nanotubes (TNTs) are sulphonated and characterized to confirm their morphological, physical and chemical characteristics. Different weight percentages (2.5, 5, 7.5 and 10 wt%) of Sulphonated TNTs (S-TNTs) are introduced into Sulphonated Poly Ether Ether Ketone (SPEEK) where the negative channels that form with the aid of sulphonic acid groups play an essential criterion for the improved proton conductivity and better water holding capacity. A tubular-designed Microbial Fuel Cell (MFC) of 300 mL volume is fabricated to test the potentiality of the self-assembled inorganic and functionalized Titanium nanotubes incorporated SPEEK membranes. SPEEK + 7.5% S-TNT exhibits a maximum power density of 121 mW m−2 with higher ion exchange capacity of 3.2 meq g−1 and lower internal resistance of 30 Ω. Biofouling investigation after 3 weeks of operation reveals that the optimized membrane displays better proton conductivity with an electrochemically stable biofilm without deteriorating the essential membrane characteristics. Preliminary microbial studies reveal the dominance of gram negative bacteria accelerating the rate of enriched extra-electrogen transfer (EET) to the anode enabling better MFC performance.