Catalysis in Extreme Field Environments: The Case of Strongly Ionized $SiO_{2}$ Nanoparticle Surfaces

TL;DR

This paper investigates how extreme electric fields influence catalysis on strongly ionized silica nanoparticle surfaces, revealing ultrafast fragmentation and water splitting mechanisms crucial for nanoscale catalysis.

Contribution

It introduces a multiscale non-adiabatic quantum molecular dynamics approach to study ultrafast surface reactions under strong field ionization conditions.

Findings

Surface silanol dissociation occurs within 50 fs.

Charge transfer induces water splitting within 150 fs.

Hole localization drives fragmentation dynamics.

Abstract

High electric fields can significantly alter catalytic environments and the resultant chemical processes. Such fields arise naturally in biological systems but can also be artificially induced through localized excitations at nanoscale. Recently, strong field excitation of dielectric nanoparticles has emerged as an avenue for studying catalysis in highly ionized environments producing extreme electric fields. While the dynamics of surface ion emission driven by ultrafast laser ionization has been heavily explored, understanding the molecular dynamics leading to fragmentation has remained elusive. To address this, we employed a multiscale approach utilizing non-adiabatic quantum molecular dynamics (NAQMD) simulations on hydrogenated silica surfaces in both bare and wetted environments under field conditions mimicking those of an ionized nanoparticle. Our findings indicate that hole localization drives fragmentation dynamics, leading to surface silanol dissociation within 50 fs and charge transfer-induced water splitting in wetted environments within 150 fs. Further insight into such ultrafast mechanisms is critical for advancement of catalysis on the surface of charged nanosystems.