# Studying the Synthesis of Silver Nanocubes and Their Structural Evolution under Controlled Galvanic Reactions

## TL;DR

This paper explores how to control the shape and composition of silver nanocages using galvanic replacement reactions and different synthesis conditions.

## Contribution

The study introduces a new method for synthesizing silver nanocubes and demonstrates how multiple factors can be used to control nanocage morphology and composition.

## Key findings

- The gold seed-mediated method for AgNC synthesis is influenced by silver ion to gold seed ratio and CTAC concentration.
- Manipulating GRR inputs like reducing agent, injection rate, and temperature leads to different nanocage structures and optical properties.
- A plausible mechanism for structural evolution under GRR is proposed and experimentally supported.

## Abstract

Galvanic replacement reaction (GRR) with or without a
reducing
agent is the most commonly used strategy to transform Ag nanocubes
(AgNCs) into nanocages, and under this approach, some limited control
over the nanocages’ morphology and composition has been previously
demonstrated. However, there is a lack of systematic study of GRR
using other factors beyond a reducing agent to finely tailor the morphology
and composition (mono- or bimetallic) of the nanocage formation. In
addition, most previous work synthesizes AgNCs using the polyol process
method, which has a number of drawbacks. In this work, we synthesized
the AgNCs using the gold seed-mediated method and found that their
morphology and yield were significantly impacted by both the ratio
of silver ions to gold seed volume as well as the concentration of
the CTAC surfactant. A detailed study was then carried out on transforming
the synthesized AgNCs to nanocages under GRR while manipulating synthesis
inputs, including the use of a reducing agent, adjusting the injection
rate, and increasing the reaction temperature. Compared to a traditional
GRR synthesis, manipulating these different inputs can result in a
dramatically different structural evolution for the nanocages, which
will impact their optical properties. This understanding allows for
the morphology and composition of the nanocages to be effectively
manipulated. We propose a plausible mechanism for the observed differing
structural evolution of the nanocages under different GRR conditions,
which is supported by evidence from further experiments.