Carbon nanoflorets

Oct. 31, 2023

Carbon nanoflorets made by IIT Bombay researchers can convert incident sunlight to heat with 87% efficiency.

About Carbon nanoflorets:

  • These are like tiny marigold flowers made only of carbon, which are called as the material carbon nanoflorets.
  • Process of synthesis
    • Researchers heated a special form of silicon dust called DFNS (for dendritic fibrous nanosilica) in a furnace.
    • Once heated, she introduced acetylene gas into the chamber.
    • The white powder turned black, a sign that carbon had been deposited on the DFNS.
    • Then they collected the black powder and treated it with a strong chemical that dissolved the DFNS away, leaving carbon particles behind.
  • The structure of the silicon particles – 50-1,200 nanometers in size—resembled spikes arranged around a sphere. 
  • Observation
    • They reported that these nanoflorets could absorb sunlight at many frequencies and convert it to heat with unprecedented efficiency.
    • The nanoflorets also didn’t easily dissipate the heat generated into the environment, making the material a good candidate for heat. 
    • The nanoflorets converted the light energy they absorbed into thermal energy—a process called solar-thermal conversion—with a remarkable efficiency of 87%.
  • The carbon nanoflorets’ high efficiency comes from three properties.
    • The nanoflorets absorb three frequencies in sunlight – infrared, visible light, and ultraviolet, while other common materials  absorb only visible and ultraviolet light.
    • Shape: As light falls on the material, the carbon cones ensure that very little is reflected back.
    • Llong-range disorder: Parts of the structure at some distance from each other possess different physical properties. As a result, heat waves in the material aren’t carried over long distances, reducing the amount of heat dissipated away.