Membrane-Free VisibleLight Driven Ca₂Fe₂O₅‑gC₃N₄ Based SingleChamber Dual Photoelectrode Photocatalytic Fuel Cells for Energy Productionand Simultaneous Water Treatment

The present study introduces a gC₃N₄ and Ca₂Fe₂O₅ photocatalytic fuel cell (PFC) system, aiming to generate power and degrade tertiary pollutants such as tetracycline, a persistent antibiotic, in contaminated water. A combination of gC₃N₄ and Ca₂Fe₂O₅ as photoelectrodes can significantly impact the efficiency, durability, and cost effectiveness of PFCs. The present study investigates the system efficiency under a solar simulator and in an LED chamber. The performance of the PFC system could be improved by incorporating 10% activated carbon into the electrodes by tuning its electrical conductivity and active sites. Material investigation using ultraviolet photoelectron spectroscopy and photoelectrochemical spectroscopy gives insights into the electronic behavior of the photoelectrodes. The PFC system under simulated solar light could achieve an open-circuit voltage (<i>V</i>_oc) of 0.11 V, a short-circuit current density (<i>J</i>_sc) of 6.83 μA cm^–2, a power density of 0.45 μW cm^–2, and a fill factor (FF) of 60%. A power density of 0.29 μW cm^–2 is achieved in LED-based PFC with a <i>V</i>_oc of 0.10 V and an <i>I</i>_sc of 5 μA cm^–2. Simultaneously, the system could degrade 78% and 77% of tetracycline in 120 min under solar simulation and LED irradiation, respectively. This study provides a comprehensive analysis of the critical properties of photoelectrodes that influence the performance of PFCs, thereby contributing to further advancements in sustainable energy systems.