The overarching goal of our team is to understand, design, and demonstrate new materials for energy storage and conversion, and environmental sensors. Our focus is on building complex structures of transition metal compounds (e.g. oxides, nitrides, sulfides) from the atomic to the micrometer level, for electrocatalysis, batteries, and photonic applications.
Our Current Projects :
Structure-Function Relations in Catalysis.
Multi-electron electrochemical reactions such as oxygen reduction reaction, oxygen evolution reaction, and carbon dioxide reduction reaction play an essential role in energy storage and conversion devices, for example, electrolyzers that use renewable electricity to transform water and carbon dioxide to energy-dense fuels, and fuel cells that react hydrogen with air to produce electricity. In an effort to design higher performing catalysts to improve the kinetics of the multi-electron electrochemical reactions, our group studies the mechanisms behind the multi-electron electrochemical processes. Our emphasis is on using well-defined surfaces as a model catalyst. Our approach combines both syntheses, electrochemical and spectroscopic characterizations, and, through our collaborator, density functional theory calculations. Our recent work has focused on controlling surface and sub-surface atoms to realize a catalyst, where the atomic compositions are rationally controlled from the base layer to top, and developing time-dependent vibrational spectroscopy to identify the nature of the catalyst in the middle of the electrochemical reaction.
Light-Chemistry Interactions in Nanophotonics
Integrated sensors are enabling technology for medical diagnostics, threat detection, and environmental monitoring. Optical-waveguide-based Raman sensors have attracted significant attention owing to their compact format, increased efficiency over conventional Raman spectrometers, and nanoscale surface sensitivity. Our group uses transition-metal oxides as a material platform for this integrated-sensor application. Transition-metal-oxide materials have several advantages, including high index, wide transparency window, and negligible fluorescence, all of which can positively contribute to the performance of the sensor device. Our approach to improving the performance of the sensor combines computational design, and experimental fabrication and testing to demonstrate sensitivity performance. Our recent work has focused on engineering photonic structures to increase detection efficiency.