George Mason team identifies technology to enhance artificial photosynthesis

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When a 4-VA Collaborative Research Grant results in the production of a novel concept for technology solutions to support energy and climate issues, while also sharing resources and data between higher education institutions in Virginia and providing faculty and student research opportunities, it is a win for all involved.

Yun Yu. Photo provided

This was achieved following 4-VA's approval of a proposal by George Mason University's Yun Yu, an assistant professor in the Chemistry and Biochemistry Department, for a grant titled "Nanoscale Visualization of Electrocatalytic Carbon Dioxide Reduction Activity at Cu Nanocatalysts."

Yu's goal was to investigate options in catalytic electrode materials to improve and enhance electrocatalysis, a process essential for harnessing sustainable energy sources for artificial photosynthesis. While nanostructures are currently recognized as the most successful catalyst for many chemical reactions, there is more to understand about tailoring their crystalline planes to improve activity and selectivity.

Yu wanted to gain deeper insights into various nanocatalysts used in carbon removal technologies. The conventional approach to conducting this study often involves measuring the entire catalyst, composed of numerous small particles with varying sizes and shapes. However, critical information, such as the impact of heterogeneities on performance, is often lost in such ensemble measurements.

Yu saw the potential for leveraging the nanoscale scanning electrochemical microscopy at George Mason to obtain detailed surface reactivity maps of nanocatalysts. However, to do so, Yu needed to acquire shape-controlled nanostructures, including copper nanowires, copper nanocubes, and nickel-iron layered nanosheets. He did so through a partnership with Sen Zhang, associate professor of chemistry at the University of Virginia.

Graduate student Dan Tran operating the scanning electrochemical microscope. Photo provided

Yu's team-graduate student Dan Tran and undergraduate students Solyip Kim, Melissa Nguyen, and Mackenzie Dickinson-played a key role in the project, receiving funding and real-world research experience. Together, they identified furfural reduction, an important reaction for sustainable biofuel generation, and they noted a distinct contrast in activity between copper and graphite support.

"These preliminary experiments have demonstrated the viability of our scanning electrochemical technique in spatially resolving catalytic activity across nanoscopic structures," said Yu. They further expanded the application to the study of nickel-iron catalysts.

"Our data suggested that adding trace amount of cerium oxide to the catalysts significantly enhances water oxidation activity. We would not have these insights without this powerful electroanalytical technique," said Yu.

The initial results have provided Yu with a springboard to develop external grant proposals to systematically study the role of cerium oxide and quantify the effects of its loading on the apparent catalytic activity of the developed catalysts.

"This 4-VA opportunity allowed us to create a partnership with UVA, create a team to implement further investigation via George Mason's nanoscale scanning electrochemical microscopy, and now apply for further funding to move this project forward," Yu said.