Assessment of Graphite, Graphene, and Hydrophilic-Treated Graphene Electrodes to Improve Power Generation and Wastewater Treatment in Microbial Fuel Cells

• Published in: Bioengineering (Basel) Vol. 10; no. 3; p. 378
• Main Authors: Borja-Maldonado, Fátima, López Zavala, Miguel Ángel
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.03.2023; MDPI
• Subjects: anode; Biochemical fuel cells; Bioengineering; Biomass; Carbon; cathode; Catholytes; Chambers; Deionization; Efficiency; Electrode materials; Electrodes; Electrolytes; Energy; Fuel cells; Graphene; Graphite; Hydrochloric acid; hydrophilic-treated graphene; Hydrophilicity; Liquor; Maximum power density; Membranes; microbial fuel cell; Microorganisms; Microscopy; Organic matter; Properties; Spectrum analysis; Substrates; Wastewater treatment; Water treatment; Mexico; United Kingdom > UK; anode; microbial fuel cell; hydrophilic-treated graphene; cathode; graphite; graphene
• ISSN: 2306-5354; 2306-5354
• DOI: 10.3390/bioengineering10030378

In this study, graphite, graphene, and hydrophilic-treated graphene electrodes were evaluated in a dual-chamber microbial fuel cell (DC-MFC). Free-oxygen conditions were promoted in anodic and cathodic chambers. Hydrochloric acid at 0.1 M and pH 1.1 was used as a catholyte, in addition to deionized water in the cathodic chamber. Domestic wastewater was used as a substrate, and a DuPontTM Nafion 117 membrane was used as a proton exchange membrane. The maximum power density of 32.07 mW·m-2 was obtained using hydrophilic-treated graphene electrodes and hydrochloric acid as catholyte. This power density was 1.4-fold and 32-fold greater than that of graphene (22.15 mW·m-2) and graphite (1.02 mW·m-2), respectively, under the same operational conditions. In addition, the maximum organic matter removal efficiencies of 69.8% and 75.5% were obtained using hydrophilic-treated graphene electrodes, for hydrochloric acid catholyte and deionized water, respectively. Therefore, the results suggest that the use of hydrophilic-treated graphene functioning as electrodes in DC-MFCs, and hydrochloric acid as a catholyte, favored power density when domestic wastewater is degraded. This opens up new possibilities for improving DC-MFC performance through the selection of suitable new electrode materials and catholytes.