Boosting power output in microbial fuel cells with sunlight-assisted natural hematite anode for enhanced wastewater treatment

Abstract

Microbial fuel cells (MFCs) hold currently great potential in energy generation and environmental remediation. The utilization of semiconducting minerals to efficiently harvest solar energy is a crucial approach for enhancing the MFC performance. Along these lines, in this work, a sunlight-assisted two-chambered MFC with hematite modified anode was developed. The hematite anode MFC exhibited maximum voltage output (85.2 ± 4.5 mV) and power density (5.2 W/m2) under light illumination conditions, which were 1.76 times and 1.63 times higher than that in dark conditions, respectively. From the acquired electrochemical results, it was demonstrated that hematite cooperative microorganisms exhibited higher current density (6.8 μA/cm2) and lower polarization resistance (77.2 Ω) under light condition, suggesting that the sunlight-assisted hematite anode facilitates the rapid electron transfer and significantly reduces the polarization loss. Furthermore, the removal percent of NO3− and Cr(Ⅵ) in hematite anode MFC were 95.50 % and 66.67 % under irradiation conditions, respectively, which were 1.3 times and 1.5 times higher than that in dark conditions. Our work provides valuable insights for harnessing solar energy through a hematite-modified anode, which holds promise for enhancing MFC performance and wastewater treatment.