Scientists find nanoparticles make it easier to create solvated electrons from light

Researchers from Rice University, Stanford University, and the University of Texas at Austin have discovered a new way to produce solvated electrons through interactions between light and metal. 

According to a press release, the process involves plasmons, or waves of electrons, that are excited when light strikes a metal nanoparticle or nanoscale imperfections on a larger metal surface. When the frequency of neighboring plasmons matched, it could resonate and reinforce each other, which produced solvated electrons. While previous research suggested plasmonic resonance could accomplish that outcome, this is the first study to clearly and successfully show the process.

“Given the long history of the field, the challenge was both proving the existence of solvated electrons and then also linking their generation to the plasmon resonance,” Stephan Link, a co-corresponding author of the research from Rice University, said in the release. “It really required teamwork and expertise from several research groups.”

In the study, published in the Proceedings of the National Academy of Sciences, the release noted that researchers from the Center for Adapting Flaws into Features (CAFF), a center for chemical innovation, funded by the National Science Foundation (NSF), showed solvated electrons could be created by shining light on silver electrodes suspended in water. They then showed they could increase the amount of these electrons by ten times as much by coating the electrodes with silver nanoparticles first. 

The researchers believe that solvated electrons could react with carbon dioxide, which would turn it into other useful molecules, such as fuels. These electrons could also help decrease greenhouse gas emissions by replacing the current process for producing ammonia-based fertilizers with an energy-efficient alternative.

In addition to Link, the study's other co-corresponding authors include Christy Landes, CAFF director, Jennifer Dionne, associate professor of materials science and engineering at Stanford, and Peter Rossky, Rice's Harry C. and Olga K. Wiess Chair in Natural Sciences and professor for both chemistry and chemical and biomolecular engineering, the release stated. The study was supported by an NSF grant, CAFF, and the Robert A. Welch Foundation.