In Operando Photoswitching of Cu Oxidation States in Cu-Based Plasmonic Heterogeneous Photocatalysis for Efficient H₂...

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Metal nanoparticles (NPs) on TiO2 are effective photocatalysts for solar-to-chemical energy conversion.
• Copper NPs on TiO2 show promise but suffer from poor oxidative stability, limiting their application.
• Ostwald ripening and ion dissolution degrade copper nanoparticles during photocatalysis.

Purpose of the Study:

• To develop a stable and efficient copper-based plasmonic photocatalyst for hydrogen production.
• To overcome the oxidative instability and Ostwald ripening of copper nanoparticles on TiO2.
• To enhance photocatalytic activity using surface plasmon resonance (SPR) effects.

Main Methods:

• Nanoencapsulation of copper oxide (CuO) nanoparticles with carbon layers on TiO2 nanobelts (TC@C).
• Photocatalytic hydrogen generation from water under light illumination.
• Three-dimensional electromagnetic wave-frequency domain (3D-EWFD) simulations to confirm SPR enhancement.

Main Results:

• Nanoencapsulation with carbon (CuO@C) suppressed Ostwald ripening and stabilized copper NPs.
• Photoreduction of CuO@C NPs yielded Cu@C NPs, a photoswitching strategy.
• The resulting Cu@C plasmonic photocatalyst exhibited enhanced activity for H2 production, even under visible light.
• SPR effect of Cu NPs was confirmed to enhance photocatalytic activity.

Conclusions:

• The developed carbon-coated copper nanoparticles on TiO2 (Cu@C/TiO2) offer a stable and highly active plasmonic photocatalyst.
• This approach enables efficient solar-to-chemical energy conversion for hydrogen production.
• The findings pave the way for scalable, multifunctional copper-based plasmonic photocatalysts for solar energy applications.