Potential of carbon nanohorn-based suspensions for solar thermal collectors

The optical characterization is reported of a new fluid consisting of single wall carbon nanohorns and ethylene glycol for solar energy applications. Carbon nanohorns play a significant role in enhancing sunlight absorption with respect to the pure base fluid. The obtained results are compared with those obtained for fluids suspending more conventional carbon forms, i.e. carbon-black particles. We found that nanohorn spectral features are by far more favourable than those of amorphous carbon for the specific application. This result shows that carbon-nanohorn based nanofluids can be useful for increasing the efficiency and compactness of thermal solar devices, reducing both environmental impact and costs.