Numerical Simulations of Nanoscale Systems

Stephen Cronin is an assistant professor in the USC Viterbi School of Engineering's Ming Hsieh Department of Electrical Engineering and holds the Gordon S. Marshall Early Career Chair in Engineering. He and his research team study photocatalytic water splitting, a process that has applications for renewable energy, including the production of hydrogen fuel. His team also explores the photocatalytic production of methane and other hydrocarbon fuels from carbon dioxide and water.

Photocatalytic processes, which employ light to drive chemical reactions, provide a method for storing the sun's energy in chemical bonds that can be released later without producing harmful byproducts. Cronin's team is developing new methods and materials to enhance these photocatalytic processes.

When absorbed by a semiconductor, light creates electron-hole pairs that are separated in energy by the bandgap of the material. This energy separation can be used to drive electrons in a circuit, as in an electrical solar cell, or to drive electrochemical redox reactions, such as water splitting or the formation of methane from carbon dioxide and water. Cronin and his team are combining strongly plasmonic metal nanoparticles, such as gold, with strongly catalytic metal oxide semiconductors, such as titanium dioxide, to enable more efficient solar energy conversion.

Cronin's team uses HPCC resources to perform detailed simulations of the electromagnetic response of plasmonic metal nanoparticles on semiconductor photocatalysts. These simulations provide a model for studying the fundamental mechanism underlying the observed catalytic enhancement, as well as the necessary data to calculate and visualize electromagnetic fields and charges in these metal and semiconductor nanostructures. The large-scale, highly parallel architecture of HPCC's resources is essential for simulating these structures, which typically require a spatial resolution of two angstroms and several million grid points.

Cronin's research is funded by a National Science Foundation Faculty Early Center Development (CAREER) Award and an Air Force Office of Scientific Research Young Investigator Award.