Optimized Ag Nanovoid Structures for Probing Electrocatalytic Carbon Dioxide Reduction Using Operando...

Area of Science:

• Electrochemistry
• Spectroscopy
• Materials Science

Background:

• Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique highly dependent on nanostructure surface properties.
• Coupling SERS with electrochemistry allows simultaneous vibrational analysis during electrocatalytic reactions.
• Optimizing nanostructures for maximum Raman enhancement is crucial but often time-consuming.

Purpose of the Study:

• To develop a systematic strategy for determining optimal nanostructure properties for electrochemically generated silver (Ag) void structures.
• To identify the specific void size that yields the highest signal enhancement for SERS.
• To apply these findings to understand the electrochemical reduction of carbon dioxide.

Main Methods:

• Fabrication of Ag-coated Si wafers decorated with polymer nanospheres of varying sizes.
• Use of bipolar electrochemistry to create a gradient of differently sized Ag void structures.
• Local evaluation of Raman enhancement using a Raman probe and characterization via scanning electron microscopy.
• High-throughput scanning droplet cell experiments to optimize electrodeposition conditions.

Main Results:

• A gradient of Ag void structures was successfully fabricated and characterized.
• Specific void sizes were identified that provide maximal SERS signal enhancement.
• Optimized electrodeposition conditions were determined for a three-electrode system.
• The optimized structure served as an effective working electrode for operando SERS.

Conclusions:

• The developed strategy efficiently identifies optimal nanostructure properties for SERS.
• The findings enable precise signal amplification for studying complex electrochemical reactions.
• This approach facilitates the spectroscopic investigation of carbon dioxide electroreduction.