# Seeing Is Believing: How Does the Surface of Silver Nanocubes from a Polyol Synthesis Change during Sample Collection, Washing, and Redispersion

## TL;DR

This paper shows how the surface chemistry of silver nanocubes changes during sample preparation steps like collection and washing, affecting their shape and stability.

## Contribution

The study introduces a method using surface-enhanced Raman scattering to track solvent effects on Ag nanocube surfaces during post-synthesis processing.

## Key findings

- Using acetone before centrifugation improves collection efficiency by inducing reversible aggregation.
- Acetone and Cl– ions coadsorb on Ag surfaces to suppress oxidative etching and preserve cubic shape.
- Washing with water or ethanol facilitates redispersion and adsorption of polyvinylpyrrolidone.

## Abstract

While the synthesis of Ag nanocubes has been extensively
studied,
sample preparation (including collection, washing, and redispersion)
after the synthesis has received far less attention. Herein, we leverage
the unique capability of surface-enhanced Raman scattering to investigate
how the solvent used for sample preparation affects the surface chemistry
of Ag nanocubes. Our findings reveal that the use of an appropriate
solvent for sample preparation plays a vital role in preserving the
cubic shape. Crushing the reaction mixture with acetone before centrifugation
greatly improves collection efficiency by inducing reversible aggregation
among the particles. It also promotes the coadsorption of the carbonyl
group from acetone and Cl– ions on the Ag surface
to suppress oxidative etching and thereby help preserve the cubic
shape. Subsequent washing of the collected nanocubes with water or
ethanol enables effective redispersion while facilitating the desorption
of Cl– ions and the adsorption of the carbonyl group
from poly­(vinylpyrrolidone). Collectively, these results underscore
the importance of processing conditions after a colloidal synthesis
in preserving the desired properties of Ag nanocubes for an array
of applications.