Multiscale Plasmonic Refractory Nanocomposites for High-Temperature Solar Photothermal Conversion

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• High-temperature solar thermal and thermochemical conversion requires refractory selective solar absorbers (RSSAs).
• Current RSSA development faces challenges in achieving broadband solar absorption and sharp spectral selectivity simultaneously.

Purpose of the Study:

• To design and fabricate a novel RSSA with enhanced optical properties.
• To establish design and fabrication guidelines for advanced RSSAs.

Main Methods:

• Utilized a ruthenium-carbon nanotube (Ru-CNT) nanocomposite structure.
• Engineered multiscale nanoparticle-on-nanocavity plasmonic modes.
• Employed conformal coating of ruthenium on carbon nanotubes (CNTs) and ruthenium nanoparticle formation at CNT tips.

Main Results:

• Achieved a total solar absorption (TSA) of 96.1% with a sharp spectral cutoff at 2.21 μm.
• Maintained over 90% TSA for incident angles up to 56°.
• Demonstrated omnidirectional, broadband solar absorption and spectral selectivity.

Conclusions:

• The Ru-CNT nanocomposite RSSA effectively addresses key challenges in selective solar absorber design.
• This work provides a pathway for full-spectrum optical and thermal control from visible to far-infrared wavelengths.
• The findings guide the development of efficient materials for high-temperature solar energy utilization.