Intensifying Upconverted Ultraviolet Emission towards Efficient Reactive Oxygen Species Generation

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Multiphoton upconversion converts near-infrared light to ultraviolet (UV) emission, enabling applications in photocatalysis and phototherapy.
• Lanthanide emitters often suffer from quenched excited states due to lattice defects and lanthanide interactions, leading to weak UV emission.

Purpose of the Study:

• To develop a novel approach for boosting UV upconversion emission in lanthanide-doped nanoparticles.
• To investigate a new class of multilayer core-shell nanoparticles with a gadolinium-rich core for enhanced upconversion.

Main Methods:

• Designed multilayer core-shell nanoparticles featuring a gadolinium-rich core and an optically inert NaYF4 interlayer.
• Employed an excitation energy lock-in strategy to confine energy migration within the core domain.
• Investigated the energy transfer mechanisms using spectroscopic analysis.

Main Results:

• Achieved over 70-fold enhancement in Gadolinium (Gd3+) emission compared to conventional nanoparticles.
• Demonstrated effective confinement of excitation energy through energy migration and the NaYF4 interlayer.
• Observed a 35.6% increase in photocatalytic reactivity and a 26.5% increase in reactive oxygen species production in ZnO-coated nanocomposites.

Conclusions:

• The excitation energy lock-in approach significantly boosts UV upconversion emission in novel core-shell nanoparticles.
• This strategy enhances photocatalytic activity and reactive oxygen species generation under near-infrared irradiation.
• Provides new insights into energy transfer in lanthanide-doped nanoparticles for advanced photocatalyst development.