A dual photoelectrode-based double-chambered microbial fuel cell applied for simultaneous COD and Cr (VI) reduction in wastewater

Cerium oxide (CeO2) and cuprous oxide (Cu2O) were used for the first time as photoanode and photocathode, respectively, in a microbial fuel cell (MFC) for simultaneous reduction of chemical oxygen demand (COD) and Cr(VI) in wastewater. The photoelectrodes, viz. Photoanode and photocathode were separately prepared by impregnating activated carbon fiber (ACF) with the respective metal oxide nanoparticles, followed by growing carbon nanofibers (CNFs) on the ACF substrate using catalytic chemical vapor deposition. The MFC, operated under visible light irradiation, showed reduction in COD and Cr(VI) by approximately 94 and 97%, respectively. The MFC also generated high bioelectricity with a current density of similar to 6918 mA/m(2) and a power density of similar to 1107 mW/m(2). The enhanced performance of the MFC developed in this study was attributed to the combined effects of the metal oxide photocatalysts, the graphitic CNFs, and the microporous ACF substrate. The MFC based on the inexpensive transition metal oxides-based photoelectrodes developed in this study has a potential to be used at a large scale for treating the industrial aqueous effluents co contaminated with organics and toxic Cr(VI). (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

In this study, CeO2 and Cu2O were utilized as photoanode and photocathode in a MFC, resulting in simultaneous reduction of COD and Cr(VI) in wastewater with high bioelectricity production.