Visible light-driven efficient overall water splitting using p-type metal-nitride nanowire arrays

Area of Science:

• Materials Science
• Renewable Energy
• Photocatalysis

Background:

• Solar water splitting is a promising renewable energy technology.
• Indium gallium nitride (InGaN) nanowires are explored for photocatalysis.
• Overcoming surface potential barriers is crucial for efficient water splitting.

Purpose of the Study:

• To develop efficient and stable photocatalysts for solar water splitting.
• To investigate the role of p-type dopants in InGaN nanowires for water dissociation.
• To achieve high solar-to-hydrogen conversion efficiency under visible light.

Main Methods:

• Controlled p-type dopant incorporation in InGaN nanowires to eliminate potential barriers.
• Fabrication of double-band p-type gallium nitride/indium gallium nitride nanowire heterostructures.
• Characterization of photocatalytic performance under visible light (400-475 nm) and concentrated sunlight.

Main Results:

• Achieved efficient and stable stoichiometric water splitting under visible light.
• Obtained an apparent quantum efficiency of ~12.3% for neutral water splitting.
• Demonstrated a solar-to-hydrogen conversion efficiency of ~1.8% using a heterostructure under concentrated sunlight.

Conclusions:

• Controlled doping of InGaN nanowires effectively eradicates surface potential barriers, enhancing photocatalytic activity.
• The developed nanowire heterostructures show significant potential for large-scale solar-fuel conversion.
• Near-surface band structure plays a dominant role in photocatalytic performance for solar water splitting.