Hydrogen evolution from water based on plasmon-induced charge separation at a TiO₂/Au/NiO/Pt system

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Metal-semiconductor plasmonic nanostructures convert light energy via plasmon-induced charge separation (PICS).
• These structures offer novel strategies for solar energy utilization, particularly in photocatalysis.
• Efficient charge separation is crucial for optimizing photocatalytic performance.

Purpose of the Study:

• To enhance PICS efficiencies for hydrogen evolution from water.
• To improve solar energy conversion using a modified photoanode system.
• To investigate the role of a nickel oxide layer in charge separation and catalytic activity.

Main Methods:

• Fabrication of a photoanode comprising titanium dioxide/gold nanoparticles coated with a p-type nickel oxide layer.
• Deposition of a platinum co-catalyst onto the nickel oxide layer.
• Coupling the modified photoanode with a platinum cathode for water splitting and methanol oxidation studies under visible light irradiation.

Main Results:

• Plasmon-induced charge separation (PICS) was observed at the gold-titanium dioxide interface under visible light.
• The engineered nickel oxide layer facilitated charge separation, driving both hydrogen evolution and methanol oxidation.
• Introduction of the platinum-modified nickel oxide layer resulted in a ~3.5-fold increase in methanol oxidation and hydrogen evolution rates at zero bias.

Conclusions:

• The developed metal-semiconductor plasmonic nanostructure significantly enhances photocatalytic efficiency.
• The nickel oxide layer plays a critical role in charge extraction and accumulation, improving overall solar energy conversion.
• The modified system demonstrates potential for efficient hydrogen production and valuable chemical synthesis using solar energy.