Light-Assisted Bio-Energy Harvesting by a Novel Photo-Cathode Microbial Fuel Cell Coupled with a Supercapacitor-Based Power Management System

Microbial fuel cells (MFCs) represent a promising avenue for sustainable energy generation, yet their commercialization is hindered by a limited scope and low power density. This study presents two novel approaches to address these challenges. First, a semiconductor RuO2–TiO2–IrO2/Ti heterojunction cathode is investigated for photoassisted MFCs, leveraging light absorption to enhance the oxygen reduction reaction (ORR). Owing to the lower cathodic internal resistance and enhanced reaction rate under light irradiation, electrochemical analyses demonstrate significantly improved power generation compared to conventional non-photobased MFCs. Second, a supercapacitor-based power management system (PMS) is designed to practically employ MFC output power for low power applications. By efficiently storing and discharging electrical energy derived from organic material oxidation by microorganisms in the anode and photo energy from the cathode, the PMS effectively kept an LED turned on, revealing its potential for real-world applications. Experimental results underscore the viability of MFC-PMS integration for powering portable low power electronic devices, providing valuable insights into optimizing MFC performance (light-assisted bioenergy harvesting) and broadening their applicability.