Heinz Frei, a senior scientist in Biosciences’ Molecular Biophysics and Integrated Bioimaging (MBIB) Division, seeks to engineer devices that emulate photosynthesis – the sunlight-driven chemical reaction that green plants and algae use to convert carbon dioxide (CO2) into cellular fuel. If the necessary technology could be refined past theoretical models and lab-scale prototypes, this idea, known as artificial photosynthesis, has the potential to generate large sources of completely renewable energy using the surplus CO2 in our atmosphere.
Biosciences researchers have developed a novel nanoscale membrane embedded with molecular wires that simultaneously chemically isolates, yet electrochemically couples, a microbial and an inorganic catalyst on the shortest possible length scale. This new modular architecture, described in a paper recently published in Nature Communications, opens up a large design space for building scalable biohybrid electrochemical systems for a variety of applications.
“The key design principle of natural photosynthesis is the closing of the photosynthetic cycle on the shortest possible length scale under membrane separation of the incompatible water oxidation and proton reduction environments,” said Heinz Frei, a senior scientist in Biosciences’ Molecular Biophysics and Integrated Bioimaging (MBIB) Division. With collaborators Eran Edri, a former postdoctoral fellow in MBIB now at Ben-Gurion University, and Shaul Aloni in the Molecular Foundry Division, Frei developed a fabrication method to make a square-inch sized artificial photosystem, in the form of an inorganic core-shell nanotube array, that implements this design principle for the first time. The method was described in a paper published earlier this year in ACS Nano.
Catalytic carbon dioxide (CO2) reduction is an important technology for the production of fuels and chemicals. Mechanistic studies have suggested that both electro- and photocatalytic approaches may share a common intermediate: a carbon dioxide radical anion (CO2–) bound to the catalyst’s surface. Now, using rapid-scan Fourier-transformed infrared spectroscopy in combination with isotopic labelling, Heinz Frei, a senior scientist in Molecular Biophysics and Integrated Bioimaging (MBIB), and colleagues have identified a carbon dioxide dimer radical anion (C2O4–) as the crucial surface intermediate during the photocatalytic reduction of CO2 on copper nanoparticles. Although recent electrochemical investigations have suggested the existence of this one-electron surface intermediate, this study, published in the Journal of the American Chemical Society (JACS), provides the first direct experimental evidence. Read more in this Nature Catalysis research highlight.
The projects of 13 Biosciences Area scientists and engineers received funding through the FY17 Laboratory Directed Research and Development (LDRD) program. The funded projects cover a broad range of topics including the study of microbiomes in relation to their environment, plants, and gut health; catalysis for solar conversion to energy; and genomic expression in tissue. Among them were three projects related to Lab-wide initiatives. Together, these efforts account for 17.5% of the $25.2 million allocated. Lab-wide, a total of 88 projects were selected from a field of 166 proposals.