Universal solvent restructuring induced by colloidal nanoparticles

TL;DR

This study reveals that colloidal nanoparticles universally induce solvent restructuring, forming ordered layers extending up to 2 nanometers, which enhances nanoparticle reactivity through a significant solvation shell.

Contribution

It demonstrates that solvent restructuring around nanoparticles is universal and influences reactivity, a novel insight supported by x-ray pair distribution function analysis.

Findings

Solvent layers of enhanced order extend up to 2 nm from nanoparticles.

Restructuring occurs in both polar and non-polar solvents.

The solvation shell contributes to nanoparticle reactivity.

Abstract

Colloidal nanoparticles, used for applications from catalysis and energy applications to cosmetics, are typically embedded in matrixes or dispersed in solutions. The entire particle surface, which is where reactions are expected to occur, is thus exposed. Here we show with x-ray pair distribution function analysis that polar and non-polar solvents universally restructure around nanoparticles. Layers of enhanced order exist with a thickness influenced by the molecule size and up to 2 nanometers beyond the nanoparticle surface. These results show that the enhanced reactivity of solvated nanoparticles includes a contribution from a solvation shell of the size of the particle itself.