Herein we report the synthesis of tin oxide (SnO2) and sodium hexahydroxostannate (Na2 [Sn(OH)6]) by varying the reaction parameters and established their ORR activity performance in the single chamber microbial fuel cell (sMFC) as cathode catalyst in both pure and mixed culture environments. The electrochemical studies reveal that the Na2 [Sn(OH)6] catalyst synthesized with higher concentration of NaOH has greater ORR catalytic activity than others in terms of onset potential and current density with a four-electron transfer process. The higher power density is also obtained using the same catalyst in the pure and mixed inoculum, which is comparable to the benchmark Pt/C in a sMFC. The developed cathode electrocatalyst can play a cost-effective material for the enriched energy recovery in the sMFC and/or other such electrochemical devices. © 2020 Elsevier B.V.