Au@TiO₂ Core-Shell Nanoparticles with Nanometer-Controlled Shell Thickness for Balancing Stability and Field...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Plasmonic core-shell nanostructures enhance photocatalysis by improving light absorption and charge separation.
• Controlling the synthesis of metal@titanium dioxide (metal@TiO2) core-shell nanoparticles, especially shell thickness, remains a challenge for optimizing photocatalytic efficiency.

Purpose of the Study:

• To develop a synthesis method for Au@TiO2 core-shell nanoparticles with tunable ultrathin shells (2-12 nm).
• To investigate the effect of shell thickness on plasmonic properties and photocatalytic efficiency.

Main Methods:

• Controlled slow hydrolysis of a titanium precursor for Au@TiO2 synthesis.
• Electromagnetic simulations and nanoscale characterization (EELS, electron tomography).
• Photocatalytic hydrogen evolution and stearic acid degradation tests.

Main Results:

• Achieved tunable ultrathin shells (2-12 nm) for Au@TiO2 nanoparticles.
• Identified an optimal shell thickness of 4 nm for enhanced plasmonic properties and photocatalytic activity.
• Demonstrated that shells <2 nm are insufficient to prevent sintering, while thicker shells weaken plasmonic coupling.

Conclusions:

• Precise control over shell thickness is critical for maximizing the performance of plasmonic core-shell nanostructures in photocatalysis.
• The study provides insights into optimizing Au@TiO2 nanoparticles for applications in hydrogen evolution and pollutant degradation.