Enhanced oxygen reduction reaction in air-cathode microbial fuel cells using flower-like Co3O4 as an efficient cathode catalyst. (27th July 2017)

• Record Type: Journal Article
• Authors: Kumar, Ravinder; Singh, Lakhveer; Zularisam, A.W.
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 30(2017)
• Page Start: 19287
• Page End: 19295
• Publication Date: 2017-07-27
• Subjects: Microbial fuel cell -- Oxygen reduction reaction -- Flower-like Co3O4 -- Power density; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.06.065
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: In this study, the potential of mesoporous flower-like Co3 O4 is investigated for the application of oxygen reduction reaction (ORR) in aqueous air-cathode microbial fuel cell (MFC). The flower-like Co3 O4 was prepared by a hydrothermal route. The X-ray photoelectron spectroscopy results suggested that flower-like Co3 O4 contained positively charged ions i.e., Co 2+ /Co 3+ on its surface that probably acted as ORR active sites. The electrochemical tests demonstrated that flower-like Co3 O4 enhanced the electrocatalytic activity of the cathode significantly as the onset potentials obtained in cyclic voltammetry and linear sweep voltammetry were more positive than the bare cathode. Besides, Tafel plots showed that Co3 O4 increased the electron transfer kinetics and achieved an exchange current density of 2.46 A/m 2, which was ∼30% higher than bare cathode. Subsequently, this improved ORR activity increased the power output in the MFC and a maximum power density of 248 mW/m 2 was achieved, which was 6.3 times higher than the bare cathode. The higher ORR activity and improved electric output in the MFC could be attributed to the excellent electrocatalytic activity of Co 2+ /Co 3+ and mesoporous nature of flower-like Co3 O4 that exposed extra active sites for oxygen molecules on the cathode surface. Graphical abstract: Highlights: Mesoporous flower-like Co3 O4 was synthesized by hydrothermal method. The addition of flower-like Co3 O4 enhanced the ORR activity of the cathodes. A maximum power density of 248 mW/m 2 was achieved in the study. The porous architecture of flower-like Co3 O4 improved the overall performance in MFCs.