Panchromatic photoproduction of H2 with surface plasmons

Area of Science:

• Nanotechnology
• Materials Science
• Photocatalysis

Background:

• Plasmonic nanostructures' optical properties are sensitive to geometry.
• This sensitivity can be leveraged for solar energy applications.

Purpose of the Study:

• To investigate the use of gold nanorods with tailored aspect ratios for enhanced light-to-hydrogen conversion.
• To explore the creation of panchromatic absorbers for solar energy harvesting.

Main Methods:

• Fabrication of multielectrode photocatalytic devices using functionalized gold nanorods.
• Measurement of light-to-hydrogen conversion efficiency with varying nanorod aspect ratios.
• Analysis of hydrogen production rates and correlation with hot electron generation.

Main Results:

• Combining gold nanorods of different aspect ratios nearly doubled H2 production compared to single-aspect-ratio devices.
• The best-performing device achieved an estimated quantum efficiency of ~0.1% across the solar spectrum.
• Hydrogen production rate was proportional to hot electron generation.
• Device operation remained stable for over 200 hours.

Conclusions:

• Tailoring the geometry of plasmonic nanostructures is crucial for optimizing photocatalytic performance.
• Multielement plasmonic absorbers offer a pathway to significantly improve solar-to-hydrogen conversion efficiency.
• The developed devices demonstrate stable and efficient hydrogen production, highlighting the potential of plasmonics in renewable energy.