Multiscale Plasmonic Refractory Nanocomposites for High-Temperature Solar Photothermal Conversion

Development of a refractory selective solar absorber (RSSA) is the key to unlock high-temperature solar thermal and thermochemical conversion. The fundamental challenge of RSSA is the lack of design and fabrication guidelines to simultaneously achieve omnidirectional, broadband solar absorption and sharp spectral selectivity at the desired cutoff wavelength. Here, we realize a ruthenium-carbon nanotube (Ru-CNT) nanocomposite RSSA with multiscale nanoparticle-on-nanocavity plasmonic modes. Ru con formally coated on the sidewalls of CNTs enables a spoof surface plasmon polariton mode for spectra selectivity; Ru nanoparticles formed at the tips of CNTs enable a localized surface plasmon resonance mode and plasmon hybridization for omnidirectional broadband solar absorption. The fabricated Ru-CNT RSSA has a total solar absorption (TSA) of 96.1% with sharp spectral cutoff at 2.21 mu m. The TSA is maintained at over 90% for an incident angle of 56 degrees. Our findings therefore guide full-spectrum optical and thermal control from visible to the far-infrared.

Automated summary

By incorporating ruthenium nanoparticles on carbon nanotubes, a refractory selective solar absorber (RSSA) with omnidirectional broadband solar absorption and sharp spectral selectivity has been achieved, maintaining high absorption even at larger incident angles.