TiO₂-supported Au₁₄₄ nanoclusters for enhanced sonocatalytic performance

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Semiconductor nanoparticles like TiO2 show promise for sonodynamic therapy and pollutant degradation via reactive oxygen species (ROS) production.
• Fast electron-hole recombination in TiO2 limits ROS yields, hindering its application.
• Gold nanoclusters (NCs) can potentially improve charge separation and catalytic efficiency.

Purpose of the Study:

• To investigate the sonocatalytic activity of TiO2-supported gold nanoclusters (Au NCs/TiO2) for hydroxyl radical (•OH) production.
• To determine the effect of different gold nanocluster sizes (Au144 vs. Au25) on sonocatalytic performance.
• To elucidate the mechanism behind enhanced •OH generation using Au NCs/TiO2 under ultrasonication.

Main Methods:

• Synthesis and deposition of Au144 and Au25 nanoclusters onto TiO2 nanoparticles.
• Sonocatalytic evaluation by monitoring hydroxyl radical production under ultrasonic irradiation.
• Analysis of electron-hole recombination suppression and charge separation efficiency.

Main Results:

• Deposition of Au144 NCs on TiO2 significantly enhanced •OH production (approx. 2-fold) compared to bare TiO2.
• Au144 NCs acted as electron traps, suppressing electron-hole recombination and promoting charge separation.
• Au25 NCs showed lower sonocatalytic activity due to less effective charge separation.
• Au144/TiO2 exhibited superior activity under ultrasonication, attributed to cavitation-induced sonoluminescence and heat, outperforming light-only irradiation.

Conclusions:

• Au144 NCs effectively enhance the sonocatalytic activity of TiO2 by improving charge separation.
• The size of gold nanoclusters is critical for optimizing sonocatalytic performance.
• Au144/TiO2 presents a promising photocatalyst for applications requiring ROS generation, such as sonodynamic therapy and environmental remediation.