A tree’s leaf, a blade of grass, a single algal cell: all make fuel from the simple combination of water, sunlight, and carbon dioxide through photosynthesis.
Chemist Daniel Nocera of Harvard University and his team joined forces with synthetic biologist Pamela Silver of Harvard Medical School and her team to craft a kind of living battery, which they call a bionic leaf for its melding of biology and technology.
Microbes within the system then feed on the hydrogen and convert carbon dioxide in the air into alcohol that can be burned as fuel.
The team’s first artificial photosynthesis device appeared in 2015, pumping out 216 milligrams of alcohol fuel per liter of water, but the nickel-molybdenum-zinc catalyst that made its water-splitting chemistry possible had the unfortunate side effect of poisoning the microbes.
With this new catalyst in the bionic leaf, the team boosted version 2.0’s efficiency at producing alcohol fuels such as isopropanol and isobutanol to roughly 10 percent.
Such a conversion is approximately ten times more efficient than natural photosynthesis.
Nocera says that by knitting fuels out of the excess CO2 in the air, this new bioreactor technology could help mitigate planet-warming pollution problems while bringing cleaner fuels to people who lack access to modern energy.