Bacteria-Affinity 3D Macroporous Graphene/MWCNTs/Fe₃O₄ Foams for High-Performance Microbial Fuel Cells

Abstract

Promoting the performance of microbial fuel cells (MFCs) relies heavily on the structure design and composition tailoring of electrode materials. In this work, three-dimensional (3D) macroporous graphene foams incorporated with intercalated spacer of multiwalled carbon nanotubes (MWCNTs) and bacterial anchor of Fe3O4 nanospheres (named as G/MWCNTs/Fe3O4 foams) were first synthesized and used as anodes for Shewanella-inoculated microbial fuel cells (MFCs). Thanks to the macroporous structure of 3D graphene foams, the expanded electrode surface by MWCNTs spacing, as well as the high affinity of Fe3O4 nanospheres toward Shewanella oneidensis MR-1, the anode exhibited high bacterial loading capability. In addition to spacing graphene nanosheets for accommodating bacterial cells, MWCNTs paved a smoother way for electron transport in the electrode substrate of MFCs. Meanwhile, the embedded bioaffinity Fe3O4 nanospheres capable of preserving the bacterial metabolic activity provided guarantee for the long-term durability of the MFCs. With these merits, the constructed MFC possessed significantly higher power output and stronger stability than that with conventional graphite rod anode.

Vertically Aligned Graphene Coating is Bactericidal and Prevents the Formation of Bacterial Biofilms

“…The continuous horizontal CVD monolayer graphene coating consistently had no deleterious effects on attachment or survival of either bacterial or mammalian cells. This highlights the possibility to use such surfaces for fabrication of bioelectrodes or biosensors, where conductivity properties of graphene can be exploited without harming the cells. By contrast, PECVD‐grown, vertically aligned graphene coating had a pronounced killing effect and effectively prevented attachment of bacteria to the coated surfaces while being harmless to mammalian cells.…”

A novel anode modified by 1,5-dihydroxyanthraquinone/multiwalled carbon nanotubes composite in marine sediment microbial fuel cell and its electrochemical performance

“…The maximum output power densities of MSMFCs are 296.11 mW·m −2 (blank), 619.38 mW·m −2 (DAQ), 517.82 mW·m −2 (MWCNTs), and 890.12 mW·m −2 (DAQ/MWCNTs composite), respectively (Figure ). Based on what we have done, the maximum output power density of composite modified MSMFC is higher than that of other methods . The output power and the corresponding current of MSMFC have been improved after the composite modification, which demonstrates a significant improvement in output power by using the mentioned method.…”

“…To improve the interaction between anode and microorganisms, MWCNTs are usually composited with polymers, electron‐transfer mediator, and so on. The latest researches show that MWCNTs can enhance the electron‐transfer rate, thereby improving the output power and stability of MFCs . But these modification may have disadvantages, such as complicated preparation process and low power.…”

Electrodeposition of graphene by cyclic voltammetry on nickel electrodes for microbial fuel cells applications

“…As the anodes can affect the power output of MFC, it is necessary to synthesize functional materials and design new structures for MFC anodes. The extracellular electron transfer between bacteria and the newly designed anodes can be improved, providing an alternative way to increase the power output density of MFC …”

“…The extracellular electron transfer between bacteria and the newly designed anodes can be improved, providing an alternative way to increase the power output density of MFC. 4,5 Composed of 2D sp2 hybridized carbon atoms, graphene is now considered as a new material for anode, [6][7][8] which attributes to its high specific surface area and excellent electrical conductivity. It has been reported that graphene can strengthen electron transfer rate between anode and bacteria, which significantly improves the output power density of MFC.…”