Hierarchically porous N-doped carbon encapsulating CoO/MgO as superior cathode catalyst for microbial fuel cell

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2020-04, Vol.385, p.123861, Article 123861
• Main Authors: Liang, Bolong, Zhao, Yubo, Zong, Mingzhu, Huo, Silu, Khan, Izhar Ullah, Li, Kexun, Lv, Cuicui
• Format: Article
• Language: English
• Subjects: Cobalt oxide; Magnesium oxide; Microbial fuel cell; N-doped porous carbon; Oxygen reduction reaction
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2019.123861

[Display omitted] •A hierarchical porous N-doped carbon encapsulated CoO/MgO nanoparticles is synthesized.•The maximum power density of CoO/MgO@NC is 2258 ± 70 mW m−2, 58.3% higher than that of NC.•More oxygen and active sites are supplied for the introduction of MgO.•CoO and MgO synergistically promote the electron transfer and ORR performance. Microbial fuel cell (MFC) has been considered a promising device to treat sewage and generate electricity. The cathode catalyst for oxygen reduction reaction is a critical factor affecting the performance of MFC. Herein, we prepared a nitrogen-doped porous carbon encapsulating CoO and MgO nanoparticles (CoO/MgO@NC) as cathode catalyst in air-cathode MFC. The maximum power density reached to 2258 ± 70 mW m−2, which was 58.3% higher than that of the control group NC (1426 ± 52 mW m−2). It was revealed that the excellent performance was partly attributed to the superior hierarchical porous structure which could provide both sufficient oxygen and more reactive sites. Besides, the multi-doping of graphitic-N, pyridinic-N, Co-Nx and Mg2+ reduced the diffusion and electron transfer resistance, promoted the H+ adsorption and electron transfer rate, and hence boosted the ORR performance. Moreover, the cost of the catalyst was only 5.4% of that of Pt/C. The porous nitrogen carbon with CoO and MgO, derived from chitosan, is an applicable cathode catalyst for its merits, such as excellent electrocatalytic activity, low cost, and ease of preparation.