Interfacial Microenvironment Effects at Laser-Made Gold Nanoparticles Steer Carbon Dioxide Reduction Product...

Area of Science:

• Nanomaterials Science
• Electrocatalysis
• Surface Chemistry

Background:

• Efficient electrocatalytic reduction of carbon dioxide (CO2) is crucial for sustainable energy solutions.
• Gold nanoparticles (AuNPs) show promise but their performance is often limited by surfactants and surface functionalization.
• Understanding interfacial effects is key to optimizing AuNP-based CO2 reduction catalysts.

Purpose of the Study:

• To investigate the role of surfactant-free gold nanoparticles in aqueous CO2 reduction electrocatalysis.
• To elucidate how interfacial ligand identity and self-assembled monolayers (SAMs) affect catalyst performance.
• To improve energy efficiency and carbon monoxide (CO) selectivity in CO2 electrocatalysis.

Main Methods:

• Pulsed laser in liquid synthesis to create surfactant-free AuNPs with a nonequilibrium cauliflower morphology.
• Functionalization of AuNPs with various n-alkanethiols and nitrogen-containing thiols to form SAMs.
• Electrocatalytic evaluation of CO2 reduction using modified AuNPs, analyzing CO selectivity and energy efficiency.

Main Results:

• Surfactant-free AuNPs exhibited superior catalytic performance compared to citrate-capped AuNPs.
• Surface modification with different thiols revealed distinct influences of ligand identity on CO2 mass transport and interfacial water behavior.
• Laser-synthesized AuNPs showed enhanced performance across all surface modifications, highlighting the benefit of surfactant-free synthesis.

Conclusions:

• Precise control over nanocatalyst surfaces is critical for understanding and optimizing CO2 electrocatalysis.
• Surfactant-free AuNPs offer a superior platform for mechanistic studies and catalyst design.
• Tailored nanomaterial functionalization provides a pathway for sustainable syngas production.