Jason K Cooper
Artificial photosynthesis, a photoelectrochemical (PEC) strategy to convert carbon dioxide and water to chemical fuels by storage of solar energy in chemical bonds, is an approach to respond to the growing global energy demand while also combating climate change. PEC reaction environments have unique material and chemical demands which drive discovery and development efforts to realize devices that are stable, efficient, scalable, and selective. We are focused on Cu-based metal oxide and nitride semiconductors due to their native p-type conductivity and broad absorption through the visible spectrum. In one study, we investigate CuBi2O4 photocathode materials grown by reactive co-sputtering with a comprehensive spectroscopic and DFT characterization methodology to expose its underlying electronic structure and optical properties. In the second study, we develop copper nitride, a promising new p-type semiconductor with 1.5 eV bandgap. Overcoming a major hurdle in the development of this material system, our tailored synthesis methods have realized photoactive material in aqueous conditions. Additionally, Cu3N derived Cu has been used for CO2 reduction resulting in a mesoporous Cu catalyst which achieved 68% C2+ products (C2H4, C2H5OH, and C3H7OH) at ~18.5 mA cm-2 and -1.0 VRHE.