Sustainable microbial fuel cells and supercapacitors derived from agricultural waste

What is it about?

With the growing demand for clean energy, many new green technologies are coming up, such as microbial fuel cells (MFCs). MFCs use microbes to convert chemical energy into electricity. They can be used for producing hydrogen, treating wastewater, and in biosensors. But their high cost and low power output hinder their widespread use. To solve this issue, the authors of this study created and tested MFCs made with Trapa natans (water chestnut) husks (TNH). First, a type of activated carbon with nanopores was derived from TNH. This was then used to make the electrodes in MFCs that used a type of bacteria called Escherichia coli. TNH was also used to make electrodes for supercapacitors (SC) that can store the power produced by these MFCs. The MFCs made with TNH were found to provide 1.9 times more power output than those made using commercial activated carbon. This is because TNH electrodes favor the growth of microbes and power generation. Likewise, the TNH SCs too could store more power owing to their TNH electrodes. Both the TNH MFCs and the SCs showed better stability and reusability in the long term.

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Photo by Andrey Metelev on Unsplash

Photo by Andrey Metelev on Unsplash

Why is it important?

It is clear that using TNH to create high power MFCs has its benefits. TNH is abundantly produced as agricultural waste. It is ultimately burned for disposal. Instead, reusing this waste in MFCs/SCs could promote a circular economy. This could also prevent the air pollution that burning TNH would otherwise cause. This way TNH can help create MFC and SC systems that are cheap, efficient, durable, and eco-friendly. This meets our need for more clean energy generation and storage solutions for the future. KEY TAKEAWAY: TNH is a common and sustainable material. It can be used to make efficient and economical MFC and SC systems.