|Nano Technology Optimizes Bacteria to Generate Electricity|
Solar panels and biofuels are indeed superior to fossil fuels in terms of carbon emissions. However, that doesn't mean they don't have limitations. Solar panels have challenges in material mining and recycling, while biofuels depend on agriculture and land. Both result in the loss of biodiversity. Researchers from the University of Cambridge in the UK have created a 'skyscraper' for bacteria. Their results were published in the journal Nature Materials under the title "3D-printed hierarchical pillar array electrodes for high performance semi-artificial photosynthesis" on March 7, 2022.
Reporting from Scitechdaily, in their research they used a three-dimensional printing method or 3D printing to make a 'nano-housing' grid. The place is a home for bacteria that love sunlight can grow quickly. The researchers were then able to extract the waste bacterial electrons left over from the photosynthesis process. These electrons can be used to power small-scale electronic objects. Previously, other studies succeeded in extracting energy from photosynthetic bacteria. What makes this study different is that researchers provide a 'home' for bacteria. The right home can increase the amount of energy they can extract.
This method competes with traditional methods for generating renewable bioenergy and has achieved solar conversion efficiencies that can outperform many current biofuel generation methods.
This finding is expected to open new avenues in the generation of bioenergy and solar energy sources (biohybrids) can become an important component in the energy mix without carbon emissions. "Our approach is a step towards manufacturing more sustainable renewable energy devices for the future," said Dr. Jenny Zhang from the Yusuf Hamied Department of Chemistry who led the research. Zhang and colleagues from the Department of Biochemistry and the Department of Materials Science and Metallurgy are working to rethink bioenergy into something sustainable and scalable.
Photosynthetic bacteria or cyanobacteria are the most abundant forms of life on Earth. For several years, researchers have been trying to reconnect the photosynthetic mechanisms of cyanobacteria to extract energy from them.
"There's a bottleneck in terms of how much energy can actually be extracted from photosynthesis, but no one really understands where the bottleneck is. Most scientists assume that the barriers are on the biological side of the bacteria, but we have found that the substantial barriers are actually on the material side," Zhang explained. Cyanobacteria need a lot of sunlight to grow, just like the surface of a lake in summer. Then, to extract the energy they produce through photosynthesis, the bacteria must attach to the electrodes. The 'nano-housing' electrodes for bacteria are made from metal oxide nanoparticles adapted to the way cyanobacteria work during photosynthesis. The electrodes are molded as pillar structures that are highly branched and dense, like a small city hence the name skyscraper. Zhang's team developed a molding technique that allows control over multiple length scales, making the structure highly customizable, which can benefit a wide range of fields. "The electrodes have excellent light handling properties, much like a tall apartment building with many windows," Zhang said. He also explained that cyanobacteria needed something they could attach to and form a community with their neighbors.
The electrodes they make allow for a balance between lots of surface area and lots of light. Once the self-assembling cyanobacteria were in their new homes, the researchers found that they were more efficient than other current bioenergy technologies, such as biofuels. This technique increases the amount of energy extracted by more than an order of magnitude compared to other methods for generating bioenergy from photosynthesis. "I'm surprised we were able to reach the numbers we did. Similar numbers have been predicted for years, but this is the first time these numbers have been shown experimentally," Zhang said.