Integrated Wastewater Remediation and Energy Production: Microfluidic Photocatalytic Fuel Cells Enabled by Dye Pollutants

Directly degrading the dyes in the wastewater is a missed opportunity. Herein, we propose a solution employing a microfluidic chip to construct a photocatalytic fuel cell (PFC) system, which can efficiently degrade tetracycline while generating electricity simultaneously under visible-light irradiation. This approach utilizes the photogenerated electrons from the dye Rhodamine B (RhB), which are effectively transferred through a gold layer to activate persulfate in water, leading to enhanced tetracycline degradation. Experimental results reveal that within one hour of reaction duration, the degradation efficiency of tetracycline within the PFC system was doubled. At a persulfate (PS) concentration of 2 mM, the system's open-circuit voltage and short-circuit photocurrent density reached 0.26 V and 0.00239 mA·cm^-2 respectively, both exceeding the values detected at 0.5 mM PS. Additionally, the system's power density was triple that at 0.5 mM PS. Notably, when the PS concentration in the system was elevated from 0.5 mM to 2 mM, the degradation efficiency of tetracycline witnessed a significant boost from 35.16% to 60.78%. This approach proffers a novel tactic for harnessing dye waste via microfluidic devices. The PFC system accomplishes not only the degradation of dyes and antibiotics but also the generation of electrical energy, substantially enhancing the energy utilization efficiency.