Microbial Fuel Cell Equipped with a Photocatalytic Rutile-Coated Cathode

This Study investigated semiconductor mineral (natural rutile) as a novel cathodic catalyst for microbial fuel cells (MFCs). Under the experimental conditions, MFCs installed with a natural rutile-coated cathode produced a maximal power density of 12.03 W/m(3) under light irradiation, much higher than that of 7.64 W/m(3) in the dark. The open circuit voltage (V-OCV) of the MFC was 519 mV when irradiated with visible light, the short-circuit photocurrent density (I-SC) was 50.91 A/m(3), and the fill factor (FF) was 45.44%. In a separate unoptimized MFC device with a switchable cathode, the maximum power density achieved with natural rutile and platinum (Pt) as a cathode catalyst was comparably at 2.7 and 3.6 W/m(3), respectively. The low incident monochromatic photon to current conversion efficiency (IPCE) (0.13%, at 420 nm) of rutile used ill tills Study indicates a potential for further material and system improvement. Results from this Study demonstrate that natural rutile. and other expected semiconductor materials, may serve as a group of cost-effective alternative catalysts to noble metals in MFC applications.