Oct, 2021 - By WMR
Scientists found a way to get more energy out of microbial fuel cells by infusing them with silver to create more conductivity.
Utilizing natural population of bacteria helps decontaminate groundwater by breaking down toxic chemical compounds, using this process renewable energy can be harnessed, for that a team of researchers at University of California, Los Angeles (UCLA) found a practical way to harness renewable energy from the process of breaking down toxic chemical compounds in contaminated ground water. The team used bacteria genus Shewanella, which is known for its energy generation potential. It is found in all types of environments including seawater and wastewater, irrespective of oxygen levels.
In Shewanella, organic waste material is broken down into tiny molecules producing electrons. When these bacteria are grown on electrodes they form microbial fuel cells that produce electricity. In order to boost the amount of electricity produced by these fuel cells, the scientists added nanoparticles of silver to electrodes that are made of graphene oxide. The bacteria use electrons generated from the process of breaking down toxic chemicals to reduce silver ions to silver nanoparticles to add them into their cells. When these silver particles go inside the bacteria, they act as microscopic transmission wires and capture more electrons created by the bacteria.
Adding silver improves electron transport efficiency in the bacteria and with this enhanced efficiency, the Shewanella films infused with silver produces above 80% metabolic electrons, which generates a power of 0.66 miliwatts per square centimetre. According to the scientists, it is the highest power density for a microbial fuel cell. In conclusion, the research shows that Shewanella when fused with silver increases current and improves efficiencies of microbial fuel cells. It also indicates that using silver fused Shewanella hybrid bacteria would make a way for enough power generation in practical use.