Fossil fuels have been used for decades as the main source of energy for various operations. However, their continued use have been recently criticized due to their significant contribution to environmental pollution. Besides, rapid growing energy demands have resulted in their depletion. As such, the development of efficient alternative and renewable energy sources is highly desirable for the realization of a sustainable economy.
This has attracted significant attention of researchers who have identified microbial fuel cells as a promising solution due to its ability to convert chemical energy into electrical energy. However, microbial fuel cells have low power density due to the high anodic over-potential as a result of the relatively sluggish extracellular electron transfer. As such, the development of an efficient anodic material is highly desirable.
Among the available microbial electrode materials, nanostructured materials enhance the performance of microbial fuel cells due to their excellent chemical properties. In particular, the two-dimensional graphene carbon material is a promising electrode material for microbial fuel cells with a proven ability to improve energy conversion. In a recently published literature, a hybrid of molybdenum carbide nanocatalysts and graphene have shown good catalytic activity and stability. Unfortunately, during the reduction process, the problem of the irreversible restacking of the two-dimensional graphene sheets is not conducive to the microbial growth.
To this note, Jiangxi Normal University researchers: Dr. Long Zou, Dr. Yunhong Huang, Xian Wu (Ph.D candidate) and Professor Zhong-er Long from the College of Life Sciences developed a hybrid anode material for microbial fuel cells to improve bioelectricity generation. Specifically, their aim was to validate the feasibility of molybdenum carbide hybridized graphene nanocomposites in enhancing interfacial electrocatalysis and microbial growth for electricity production in microbial fuel cells. Their research work is currently published in the research journal, Journal of Power Sources.
In brief, the research team initiated their experimental work by fabricating anode material based on molybdenum nanoparticles functionalized graphene nanocomposites using a layer-by-layer electrostatic assembly method. This was consequently followed by high-temperature carburization. In particular, Shewanella putrefaciens cells were used as an electricigen to test the bioelectrocatalytic of the developed anodic material in enhancing the overall performance of microbial fuel cells.
The authors observed that molybdenum nanoparticles functionalized graphene nanocomposites electrodes significantly improved the bioelectrocatalytic activities and bacterial biofilm growth as compared to the undecorated graphene. This was attributed to its biocompatibility and chemical flexibility which enabled the formation of compact electroactive biofilm by the Shewanella putrefaciens. In addition, electroactive biomolecules were generated at the electrode interface thus resulting in the improved transfer of extracellular electrons from the bacterial cells to the electrode. Furthermore, an output power density of up to 1697 mW/m2 was achieved at reliable stability.
In summary, the Jiangxi Normal University scientists successfully developed a hybrid anode for efficient bioelectricity generation. In general, the study presents vital information for the development of new microbial electrode materials for enhanced bioelectricity production. Alliteratively, it will boost production of renewable energy as an alternative to fossil fuels thus enhancing sustainability.
Zou, L., Huang, Y., Wu, X., & Long, Z. (2019). Synergistically promoting microbial biofilm growth and interfacial bioelectrocatalysis by molybdenum carbide nanoparticles functionalized graphene anode for bioelectricity production. Journal of Power Sources, 413, 174-181.Go To Journal of Power Sources