Three-dimensional graphene nanosheets as cathode catalysts in standard and supercapacitive microbial fuel cell

Kodali, Mounika; Kabir, Sadia; Soavi, Francesca; Serov, Alexey; Atanassov, Plamen; Santoro, Carlo

Abstract

© 2017 The Authors Three-dimensional graphene nanosheets (3D-GNS) were used as cathode catalysts for microbial fuel cells (MFCs) operating in neutral conditions. 3D-GNS catalysts showed high performance towards oxygen electroreduction in neutral media with high current densities and low hydrogen peroxide generation compared to activated carbon (AC). 3D-GNS was incorporated into air-breathing cathodes based on AC with three different loadings (2, 6 and 10mgcm−2). Performances in MFCs showed that 3D-GNS had the highest performances with power densities of 2.059±0.003Wm-2, 1.855±0.007Wm-2 and 1.503±0.005Wm-2 for loading of 10, 6 and 2mgcm−2 respectively. Plain AC had the lowest performances (1.017±0.009Wm-2). The different cathodes were also investigated in supercapacitive MFCs (SC-MFCs). The addition of 3D-GNS decreased the ohmic losses by 14–25%. The decrease in ohmic losses allowed the SC-MFC with 3D-GNS (loading 10mgcm−2) to have the maximum power (Pmax) of 5.746±0.186Wm-2. At 5mA, the SC-MFC featured an “apparent” capacitive response that increased from 0.027±0.007F with AC to 0.213±0.026F with 3D-GNS (loading 2mgcm−2) and further to 1.817±0.040F with 3D-GNS (loading 10mgcm−2).

• Journal Article Type: Article
• Acceptance Date: Mar 28, 2017
• Online Publication Date: Apr 9, 2017
• Publication Date: Jan 1, 2017
• Deposit Date: Apr 20, 2018
• Publicly Available Date: Apr 20, 2018
• Journal: Journal of Power Sources
• Print ISSN: 0378-7753
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 356
• Pages: 371-380
• DOI: https://doi.org/10.1016/j.jpowsour.2017.03.135
• Keywords: 3-D graphene nanosheets, microbial fuel cell (MFC), supercapacitive microbial fuel cell (SC-MFC), power generation, capacitance
• Public URL: https://uwe-repository.worktribe.com/output/883793
• Publisher URL: http://dx.doi.org/10.1016/j.jpowsour.2017.03.135
• Contract Date: Apr 20, 2018