Bismuth-impregnated ruthenium with activated carbon as photocathode catalyst to proliferate the efficacy of a microbial fuel cell

Ruthenium (Ru) was impregnated with bismuth (Bi) to reduce the spectrum demand for the excitation of Ru to employ it as photocathode catalyst (Bi-Ru) in a microbial fuel cell (MFC) to ameliorate its power output in the presence of visible spectrum. The coulombic efficiency (CE) and power density of an MFC with Bi-Ru (MFC-BiRu) were 26.7 ± 0.8% and 10.0 ± 0.5 W/m3, respectively, which were two and six times higher than the control MFC that was operated without any cathode catalyst. Moreover, the CE and power density of the MFC-BiRu was 12.5% and 22% higher than the MFC that was operated with platinum (MFC-Pt) as the cathode catalyst (24.0 ± 0.7% and 8.2 ± 0.4 W/m3, respectively). Furthermore, the chemical oxygen demand (COD) removal efficiency and net energy recovery (NER) of MFC-BiRu were 91.8 ± 1.5% and 722 W-h/m3, which was almost 10% and 1.8 times higher than the MFC-Pt, respectively. Therefore, the results illustrated that Bi-Ru could be a plausible alternative to replace Pt as a cathode catalyst; therefore, rendering the field-scale application of MFC.