Method for forming a bimetallic core-shell nanostructure
A method forms a bimetallic core-shell nanostructure. The bimetallic core-shell nanostructure comprises a core comprising silver and a shell comprising gold. The bimetallic core-shell nanostructure may be used in various technical fields, such as surface-enhanced Raman scattering (SERS), photovoltaic cells, biomedical, bioimaging and biosensing applications.
1. A method for forming a bimetallic core-shell nanostructure, wherein the core comprises silver and the shell comprises gold, the method comprising forming a pure gold shell on a silver nanostructure core by simultaneously adding a gold precursor at a flow rate of about 1 to 3 ml/h and a reducing agent at a flow rate of about 1 to 3 ml/h to a solution containing silver nanoparticles, wherein the reducing agent comprises hydroxylamine solution or a hydroxylamine salt.
2. The method of claim 1 , wherein prior to or during adding the reducing agent, a basic solution is added to the reducing agent.
3. The method of claim 1 , wherein a reaction mixture comprising the solution, the gold precursor, and the reducing agent is placed in a container placed in an ice bath.
4. The method of claim 1 , wherein the reaction mixture is continuously stirred.
5. The method of claim 1 , wherein the flow rate of the reducing agent is variable.
6. The method of claim 1 , wherein the flow rate of the gold precursor is variable.
7. The method of claim 1 , wherein the gold precursor is selected from the group consisting of chloroauric acid (HAuCl 4 ), gold (III) chloride (AuCl 3 ), gold (I) chloride (AuCl), and a mixture thereof.
8. The method of claim 1 , wherein the reducing agent has a concentration of 100 mM or less.
9. The method of claim 8 , wherein the concentration of the reducing agent is 10 mM or less.