In Harvard University’s Department of Chemistry and Chemical Biology, the goal isn’t just to isolate problems but to find solutions to our planet’s most pressing issues. One of those issues is how to generate efficient, renewable energy — and researchers may have just found a solution in a device dubbed “bionic leaf 2.0” because it functions even more efficiently than the fastest-growing natural plants. They’ve published a paper detailing their work in the journal Science this week.
“Our focus is actually on solutions – discovering and creating new process and new materials to change the energy landscape” Daniel Nocera, Professor of Energy at Havard University, said in a video interview with the Harvard Gazette, “One of the projects is literally [discovering] what’s in between. I have sunlight, I have water, CO2 and fuel, but what’s in between? In nature it’s a leaf. What we’ve invented is an artificial leaf.”
Place the bionic leaf in water, apply sunlight, and voilà! Hydrogen pops out of one side and oxygen pops out of the other. When burned with oxygen, hydrogen fuel’s only emission is water, so the hydrogen product can be applied to any number of sustainable applications to power vehicles and electrical devices. The hydrogen created by the artificial leaf can also be fed to an engineered organism that turns the molecules into liquid fuel, said Nocera.
The bionic leaf 2.0 improves on an artificial leaf developed by Nocera and co-creator Pamela Siler, Professor of Biochemistry and Systems Biology at Harvard Medical School. Nocera and Silver’s original design could convert solar energy to isopropanol but also emitted molecules that destroyed the bacteria’s DNA. In order to overcome this side effect, the the system had to function at unusually high voltages and with reduced efficiency. The new system is far more practical, and is capable of converting solar energy to biomass with 10 percent efficiency, compared to 1 percent efficiency found in nature.
The discovery opens new potential for renewable energy but breeds many new (welcome) challenges, said Nocera. What would a hydrogen-powered world look like? Will artificial leaves replace power plants and gas stations? With this technology, self-sustainability may become an option for low- and high-socioecomic communities alike, and for city dwellers as well as those living off the grid.
