Stabilizing ultrasmall Au clusters for enhanced photoredox catalysis

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Visible light photosensitizers based on ligand-protected gold (Au) clusters are gaining interest for photoredox catalysis.
• A significant challenge is maintaining the long-term photostability of Au clusters, especially at the metal-support interface.

Purpose of the Study:

• To develop a simple and effective method for enhancing the photostability of glutathione-protected gold clusters (Au GSH clusters).
• To improve the photocatalytic efficiency and stability of Au GSH clusters supported on SiO2 spheres.

Main Methods:

• Utilized multifunctional branched poly-ethylenimine (BPEI) for surface charge modification, reduction, and stabilization of Au GSH clusters on SiO2 spheres.
• Employed sequential coating of thickness-controlled TiO2 shells to create core-shell SiO2-Au GSH clusters-BPEI@TiO2 composites.
• Investigated the photostability and photocatalytic efficiency of the developed composite materials under prolonged light illumination.

Main Results:

• The BPEI modification successfully enhanced the photostability of Au GSH clusters on SiO2 supports.
• The TiO2 shell coating significantly improved photocatalytic efficiency.
• The resulting SiO2-Au GSH clusters-BPEI@TiO2 core-shell composites demonstrated high photostability during extended light exposure.

Conclusions:

• A joint strategy involving interfacial modification with BPEI and composition engineering with TiO2 shells effectively stabilizes ultrasmall Au clusters.
• This approach provides a facile guideline for designing robust Au cluster-based composites for photoredox catalysis applications.
• The developed materials show promise for improved activity and durability in targeted catalytic processes.