Synthesis of Tungstate Oxide/Bismuth Tungstate Composite and Application in Microbial Fuel Cell as Superior Low-Cost Cathode Catalyst than Platinum

Low cost tungsten oxide/bismuth tungstate (WO3/Bi2WO6) composite was synthesized and used as cathode catalyst in microbial fuel cell (MFC). Almost 1.5 times increment in specific surface area of WO3/Bi2WO6 composite was observed as compared with WO3 and WO3/Bi2WO6 exhibited efficient oxygen reduction reaction (ORR) having a current peak of 8.1 mA at - 12.6 mV during cyclic voltammetry analysis, demonstrating less ORR overpotential. The MFC using WO3/Bi2WO6 catalysed cathode could recover a power density (PD) of 145 +/- 4.5 mW/m(2) and coulombic efficiency (CE) of 28.3 +/- 1.5%, followed by 35 +/- 5.8 mW/m(2) and 17.5 +/- 2.4%, respectively, for MFC with WO3 catalyzed cathode and 10.4 +/- 3.2 mW/m(2) and 10.3 +/- 0.9%, respectively, for MFC without any cathode catalyst. Moreover, the PD and CE of 138 +/- 6.8 mW/m(2) and 27.5 +/- 2.0%, respectively, obtained from MFC using Pt/C cathode catalyst, was slightly lower than the MFC with WO3/Bi2WO6 catalyst on cathode. The specific power recovery per unit cost of cathode fabrication of 23.8 mW/$ obtained from MFC with WO3/Bi2WO6 catalyzed cathode is higher than the MFC with Pt/C (12.2 mW/$), making it low cost alternative for scaling-up of MFCs. (C) 2018 The Electrochemical Society.