Graphitized corncob 3D Biomass-driven anode for high performance batch and continuous modes Air-Cathode microbial fuel cells working by domestic wastewater

Effective 3D anode was prepared by graphitization of corncob biomass at high temperature under an inert atmosphere. As an anode in the microbial fuel cells, the proposed electrode revealed very good performance in both batch and continuous modes when the process parameters were optimized. The physicochemical characterizations indicated that the surface of the prepared anode is decorated by micro porous layers array and composed of SiO2-incorporated graphite. Moreover, investigation the electrical properties showed very good electrical conductivity dependent on the preparation temperature; 6.9, 8.6 and 8.9 S/m for the electrode prepared at 900, 1000 and 1100 degrees C, respectively. The performance of the proposed anode was evaluated in air-cathode single chamber microbial fuel cell driven by domestic wastewater without using exterior microorganisms. The electrochemical measurements, for the batch mode cell, displayed high power density generation upon utilizing the corncob electrode compared to commercial anodes; 100 +/- 8, 135 +/- 11 and 2010 +/- 85 mW/m2 from cells assembled using carbon paper, carbon cloth and corncob 1100 degrees C, respectively. Moreover, addition of sodium acetate strongly enhanced the cell performance as the generated power density was increased from 475 +/- 30 to 1963 +/- 90 mW/ m2 after addition of the salt (5 g/l), however the experimental results indicated that 5 g/l is the optimum salt concentration. In a continuous mode cell, the results concluded that the proposed 3D anode can be used fresh or after colonization of a biofilm. Interestingly, the generated power from the continuous mode cell is higher than the batch mode system due to mass transfer resistance elimination.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

An effective 3D anode was prepared by graphitization of corncob biomass at high temperature. The proposed electrode showed excellent performance in microbial fuel cells when optimized process parameters were used. Physicochemical characterizations revealed that the prepared anode had a surface decorated with micro porous layers and was composed of SiO2-incorporated graphite. The electrical properties showed good electrical conductivity dependent on the preparation temperature. The performance of the anode was evaluated in air-cathode single chamber microbial fuel cell using domestic wastewater, and high power density generation was observed compared to commercial anodes, especially with the addition of sodium acetate. In continuous mode, the proposed anode showed higher power generation than in batch mode due to elimination of mass transfer resistance.