Growth and reductive transformation of a gold shell around pyramidal cadmium selenide nanocrystals

TL;DR

This study explores the controlled growth and transformation of gold shells around pyramidal CdSe nanocrystals, revealing how synthesis conditions influence nanoparticle structure and potential applications in photocatalysis and optoelectronics.

Contribution

It demonstrates the ability to tune gold domain size and induce structural transformation in hetero nanocrystals through synthesis parameters and irradiation or chemical reduction.

Findings

Gold shell growth can be controlled between 1.4 nm and 3.9 nm.

Structural transformation of gold shells can be induced by electron beam irradiation or chemical reduction.

Surface chemistry significantly influences hetero nanoparticle synthesis and seed reactivity.

Abstract

We report the growth of an unstable shell-like gold structure around dihexagonal pyramidal CdSe nanocrystals in organic solution and the structural transformation to spherical domains by two means: i) electron beam irradiation (in situ) and (ii) addition of a strong reducing agent during synthesis. By varying the conditions of gold deposition, such as ligands present or the geometry of the CdSe nanocrystals, we were able to tune the gold domain size between 1.4 nm to 3.9 nm and gain important information on the role of surface chemistry in hetero nanoparticle synthesis and seed reactivity, both of which are crucial points regarding the chemical design of new materials for photocatalysis and optoelectronic applications.