Bacteria-coated nanofiber electrodes digest pollutants


Bacteria-coated nanofiber electrodes digest pollutants

Carbon nanofibers coated with PEDOT in a scanning electron microscope image. Credit: Juan Guzman and Meryem Pehlivaner/Provided
Cornell materials scientists and bioelectrochemical engineers may have created an innovative, cost-competitive electrode material for cleaning pollutants in wastewater.

The researchers created electro-spun electrodes and coated them with a conductive polymer, called PEDOT, to compete with carbon cloth electrodes available on the market. When the PEDOT coating is applied, an electrically active layer of bacteria – Geobacter sulfurreducens – naturally grows to create electricity and transfer electrons to the novel .

The conducting nanofibers create a favorable surface for this bacteria, which digests pollutants from the wastewater and produces electricity, according to the research.

“Electrodes are expensive to make now, and this material could bring the price of electrodes way down, making it easier to clean up polluted water,” said co-lead author Juan Guzman, a doctoral candidate in the field of biological and environmental engineering.

Under a microscope, the carbon nanofiber electrode resembles a kitchen scrubber. The electrode was made by co-lead author Meryem Pehlivaner, M.S. ’13, currently a doctoral student at Northeastern University, with senior author Margaret Frey, professor of fiber science and an associate dean of the College of Human Ecology. Pehlivaner fabricated the carbon nanofibers via electrospinning and carbonization processes. After a few hours electrospinning, a thick nanofiber sheet – visible to the naked eye – emerges.

Pehlivaner reached out to Guzman and senior author Lars Angenent, professor of biological and , for collaboration in applying the carbon nanofiber electrodes to simultaneous and production of electrical energy.

The customizable carbon nanofiber electrode was used for its high porosity, surface area and biocompatibility with the bacteria. By adhering PEDOT, the material gets an improved function, according to the researchers.

Guzman said do not employ this method – yet. On a large scale, the bacteria at the electrode could capture and degrade pollutants from the wastewater that flows by it. Such a technology can improve wastewater treatment by allowing systems to take up less land and increase throughput.

Concepts like this happen on campuses where faculty and students want to communicate and collaborate, Angenent said. “This defines radical collaboration,” he said. “We have fiber scientists talking to environmental engineers, from two very different Cornell colleges, to create reality from an idea – that was more or less a hunch – that will make cleaning better and a little more inexpensive.”

The research, “Performance of Electro-Spun Carbon Nanofiber Electrodes With Conductive Poly (3,4-Ethylenedioxythiophene) Coatings in Bioelectrochemical Systems,” will be published July 15 in the Journal of Power Sources.


Explore further: Building a better microbial fuel cell—using paper

More information:
Juan J.L. Guzman et al. Performance of electro-spun carbon nanofiber electrodes with conductive poly(3,4-ethylenedioxythiophene) coatings in bioelectrochemical systems, Journal of Power Sources (2017). DOI: 10.1016/j.jpowsour.2017.03.133

__

This article and images was originally posted on [Phys.org – latest science and technology news stories] June 28, 2017 at 08:24AM

by Blaine Friedlander

 

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s