Researchers Infuse Bacteria with Silver to Boost Power Efficiency in Fuel Cells

A UCLA-led team of engineers and chemists has taken a significant advance in advancing microbial fuel cells-a modern technology that uses natural bacteria to draw out electrons from organic matter in wastewater to produce electric current. Research detailing the innovation was just recently released in Scientific research.

“Living energy-recovery systems making use of microorganisms discovered in wastewater offer a one-two punch for environmental sustainability efforts,” claimed co-corresponding author Yu Huang, a teacher and also chair of the Materials Scientific Research andEngineering Department at the UCLA Samueli College of Engineering. “The all-natural populations of bacteria can help decontaminate groundwater by breaking down unsafe chemical compounds. Now, our research study likewise shows a practical method to harness renewable energy from this process.”.

The team concentrated on the microorganisms genus Shewanella, which have been widely studied for their energy-generation capabilities. Despite oxygen degrees, they can expand and thrive in all kinds of settings-including dirt, wastewater, and saltwater.

Shewanella types naturally break down natural excrement into smaller molecules, with electrons resulting from the metabolic process. When the bacteria expand as films on electrodes, a few electrons can be recorded, forming a microbial fuel cell that creates electricity.

Nevertheless, microbial fuel cells powered by Shewanella oneidensis have previously not captured enough currents from the microorganisms to make the technology sensible for industrial use. A couple of electrons can move quickly enough to get away the microorganisms’ membranes and go into the electrodes to supply adequate electric currents and power.

To address this problem, the researchers included nanoparticles of silver to electrodes composed of a type of graphene oxide. The nanoparticles launch silver ions, which bacteria lower to silver nanoparticles utilizing electrons generated from their metabolic process and afterward include right into their cells. When inside the bacteria, the silver fragments act as tiny transmission cables, catching even more electrons created by the bacteria.

“Adding the silver nanoparticles right into the microorganisms is like producing a devoted express lane for electrons, which enabled us to extract even more electrons and at faster rates,” said Xiangfeng Duan, the research’s other equivalent writer and a professor of chemistry and also biochemistry at UCLA.

With significantly enhanced electron transport performance, the resulting silver-infused Shewanella film outputs more outstanding than 80% of the metabolic electrons to an external circuit, creating a power of 0.66 milliwatts per square centimeter-more than double the previous best for microbial-based fuel cells.

With the raised existing and better effectiveness, the research study, which the Workplace of Naval Study supported, showed that fuel cells powered by silver-Shewanella crossbreed microorganisms may lead the way for acceptable power outcome in experimental setups.

Reference: Silver nanoparticles boost charge extraction efficiency in Shewanella microbial fuel cells, Science (2021). DOI: 10.1126/science.abf3427