Does it have to be carbon? Metal anodes in microbial fuel cells and related bioelectrochemical systems

Abstract

Here we propose copper as a high performance and economically viable anode material for microbial bioelectrochemical systems.

Application of 3D Printed Porous Copper Anode in Microbial Fuel Cells

“…This observation is within the range of copper concentration obtained by Zhu and Logan (2014), however, is completely different from studies by Baudler et al since no metal ions were detected in the effluent of their MFC chambers (Baudler et al, 2015). This could be probably attributed to the anode potential (−0.2 V vs. Ag/AgCl) set in studies by Baudler et al, which was significantly lower than the copper oxidation potential to prevent the metal corrosion (Baudler et al, 2015(Baudler et al, , 2017. Nevertheless, in our case, the anode potential was never set (due to the lack of proper equipment), resulting in relatively high anode potential in MFCs and dissolving copper ions from the very beginning.…”

“…As there were no copper ions in the feeding media except for the very minimum amount in the mineral solution (< 30 µg/L), the copper ions detected came from nowhere but the 3D-PPC anodes. This observation is within the range of copper concentration obtained by Zhu and Logan (2014), however, is completely different from studies by Baudler et al since no metal ions were detected in the effluent of their MFC chambers (Baudler et al, 2015). This could be probably attributed to the anode potential (−0.2 V vs. Ag/AgCl) set in studies by Baudler et al, which was significantly lower than the copper oxidation potential to prevent the metal corrosion (Baudler et al, 2015(Baudler et al, , 2017.…”

“…This also explains the much better performance of MFCs with carbon cloth anodes. However, when we look at the bacterial adhesion on copper anodes, no thick biofilm was found on electrode surface like carbon cloth and copper-based MFC anodes reported by Baudler et al (2015Baudler et al ( , 2017. The huge difference of biofilm thickness between 3D-PPC anodes we observed and copper anode reported by Baudler et al (Baudler et al, 2015 could be probably attributed to the different bacterial cultures as MFC inoculum.…”

“…Apart from carbon materials, metal electrodes, such as 3D stainless steel structures, have been reported to have an equal or even better performance compared with carbon materials (Pocaznoi et al, 2012;Guo et al, 2014Guo et al, , 2015Ketep et al, 2014;Baudler et al, 2015). However, three-dimensional (3D) metal porous anode with fine and single pore size have been seldom studied in MFC.…”

“…However, it's usually energyintensive to fabricate carbonaceous electrodes, since it requires high temperatures for material carbonization. Considering 3D printed matrixes could also be easily metalized through polymer surface modification with copper (Zhang et al, , 2017 and highly conductive copper anode in MFC with mixed cultures exhibited ambiguous properties (Zhu and Logan, 2014;Baudler et al, 2015Baudler et al, , 2017, it would be of great interest to test whether 3D printed copper anode could enhance the bioelectricity generation and biofilm growth of pure culture in microbial fuel cells.…”