An international team of researchers around Prof. Matthias Kling at SLAC National Accelerator Laboratory and Stanford University has now successfully captured the spatiotemporal evolution of charge density on single silicon dioxide (SiO₂) nanoparticles with femtosecond precision, a feat previously deemed unattainable. Their study, “Tracking Surface Charge Dynamics on Single Nanoparticles,” has been published in the latest issue of Science Advances.

By employing time-resolved reaction nanoscopy, a technique developed by the team, they have demonstrated the visualization of the redistribution of initially localized surface charges and their ability to soften molecular bonds on the surface. The results shed light on the complex interplay between charge diffusion, charge loss, and molecular bonding in the presence of charges.

“This breakthrough opens up exciting possibilities for studying new catalysts and understanding fundamental physical and chemical processes at the nanoscale,” said Ritika Dagar, PhD student in the Kling group and lead author of the study.

Original publication:

Tracking Surface Charge Dynamics on Single Nanoparticles

Ritika Dagar, Wenbin Zhang, Philipp Rosenberger, Thomas M. Linker, Ana Sousa-Castillo, Marcel Neuhaus, Sambit Mitra, Shubhadeep Biswas, Alexandra Feinberg, Adam M. Summers, Aiichiro Nakano, Priya Vashishta, Fuyuki Shimojo, Jian Wu, Cesar Costa Vera, Stefan A. Maier, Emiliano Cortés, Boris Bergues & Matthias F. Kling

Science Advances 10, 32 (2024)

 

Picture description:

Movie of a charge diffusion process on the surface of a nanoparticle after its interaction with an ionizing laser pulse. OH Bonds on the surface (oxygen: red; hydrogen: white) are stretched under the influence of the local charge (expanding yellow glow). In the experiments, each frame is taken by exposing the nanoparticle to a second delayed laser pulse that breaks the stretched bonds. The angular distribution of the escaping hydrogen ions, which are recorded in the experiment, provides a direct image of the transient surface charge distribution.

Illustration: RMT.Bergues.