RII Track-4:NSF: Integrated Electrochemical-Optical Microscopy for High Throughput Screening of Electrocatalysts

In light of the global effort to combat climate change by transitioning to cleaner energy sources, the field of electrochemistry has become essential in making renewable energy practical. Clean electrical energy can be used to drive various chemical reactions, such as converting carbon dioxide into valuable products and producing hydrogen. The efficiency of these reactions largely depends on electrocatalysts, which are materials that enable these reactions to occur efficiently. Traditionally, these electrocatalysts have been tested using conventional electrochemical methods. However, these methods have two key limitations, 1) They provide an average measure of electrocatalyst efficiency, which masks the differences among individual catalysts. 2) They offer limited insights into the mechanisms and activity happening at the complex electrocatalyst interface. This project aims to address these limitations by developing a correlated electrochemical-optical microscope capable of testing electrocatalysts individually and in a high-throughput manner. Students involved in this project will gain valuable experience in new measurement and characterization techniques, as well as cutting-edge nanofabrication methods, significantly enhancing their technical skills. Furthermore, the Sundaresan Laboratory plans to engage undergraduate and K-12 students from minority-serving institutions in Mississippi through summer research programs and outreach activities to encourage students to pursue STEM degrees. The RII Track-4 EPSCoR Research Fellows project would provide a fellowship to an Assistant Professor and offer training to a graduate student at the University of Mississippi (UM). Nanoparticle electrocatalysts exhibit heterogeneity in size, shape, and surface chemistry, leading to differences in reactivity among them. Traditional electrochemical measurements reflect the average behavior of a heterogeneous system and do not account for individual variations. The overarching goal of this project is to develop and employ high-resolution scanning probe electrochemical microscopy - scanning electrochemical cell microscopy (SECCM) - coupled with novel optical methods for high-throughput screening of electrocatalysts at a single-entity level. This will be accomplished under the mentorship of Prof. Lane Baker, Texas A&M University, a world leader in scanning probe techniques. The correlated SECCM-optical technique will: 1) probe the electroactivity of an array of individual electrocatalysts with a well-defined particle-to-particle distance in a direct approach rather than the raster scan approach, and 2) validate electrofluorogenic probes for use as a proxy for measuring electrochemical activity. These two strategies enable high-throughput and massively parallel screening of electrocatalysts. Furthermore, this approach offers insights into how each entity uniquely contributes to the ensemble response seen in traditional electrochemical measurements. The broader impacts include a new measurement technique for the state of Mississippi, available for training graduate and undergraduate students through research and analytical chemistry courses at UM, as well as outreach activities for underrepresented students with the Electrochemical Society (ECS) chapter at UM. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.