The Peidong Yang Group in the UC Berkeley College of Chemistry published a study Tuesday revealing an advancement to efficiently produce oxygen from carbon dioxide and sunlight using both organic and inorganic components in a hybrid device — technology that could one day be used to support sustainable life on Mars.
Professional investigator of the study Peidong Yang, campus professor of chemistry and S.K. and Angela Chan Distinguished Professor of Energy, said the hybrid of bacteria and nanowires allows for a reaction similar to photosynthesis to occur. Yang added that their research has been ongoing for the past nine years.
“We are taking the best of both biology and materials to mimic nature and perform better,” said former campus graduate student researcher and an author of the study Chong Liu.
The study was funded by NASA’s Center for the Utilization of Biological Engineering in Space, or CUBES, program.
According to Stefano Cestellos-Blanco, a campus graduate researcher on the study, the study opens the door for the possibility of sustainable life on Mars.
“Basically our mission through that institute is to figure out a way to deploy a mission to Mars,” Cestellos-Blanco said. “One of the ways we can do that is by using living catalysts to fix CO2 in the Martian atmosphere into carbon products that we can later use and upgrade.”
The process is based on the bunching together of bacteria in a nanowire that takes carbon dioxide and water, which produces oxygen and acetate, a chemical used in the creation of usable items such as plastic.
Their first model was made in 2015 and achieved an energy efficiency conversion rate similar to that of a plant, about 0.4%, according to Yang. As of now, the research is being done on a laboratory scale that is relatively small.
“Fundamentally, the basic science is there and shows our basic design is working,” Yang said. “We just need to spend more time to further improve the device performance and think about how to scale up.”
Yude Su, first author of the study and a former graduate student in the Peidong Yang Group, developed the idea that efficiency could be increased by packing the cells closer together. When they tried to do so, however, the bacteria moved away from the nanowire and the system failed.
The researchers discovered that the bacteria is sensitive to the pH of the water around the nanowires. After optimizing the pH, the device’s efficiency rate increased from 0.4% to 3.6%.
Cestellos-Blanco said the study is also used to impact and add to literature to assist in creating a better “carbon economy” by reusing carbon waste and ultimately combat climate change.
“Think about global warming — converting CO2 using sunlight — and deep space — Mars mission converting CO2 to all sorts of useful chemicals while producing oxygen,” Yang said. “This is a large impact.”