“Carbon onion” is a kind of giant fullerene, named for its concentric multilayer structure similar to the onion. It is widely used in aerospace, energy, biomedicine, environmental remediation and other fields. Photo: Bailu Video

Researchers at a Chinese university have discovered a natural onion-like fullerene, or "carbon onion," with an outer diameter of about 55 nanometers, making it the largest natural "carbon onion" ever found on earth.

The research team discovered the world's largest natural carbon onion in anthracite coal collected in East China's Fujian Province, and discovered a natural multi-nucleated carbon onion for the first time.

"Carbon onion" is a kind of giant fullerene, named for its concentric multilayer structure similar to the onion. It is widely used in aerospace, energy, biomedicine, environmental remediation and other fields.

The method of making carbon onions in the laboratory has long been mastered, but scientists have been working to find natural carbon onion.The discovery of natural carbon onion in the coal field has implications for the future search of natural carbon onion.

"It is further evidence that carbon onion is not as scarce as previously thought and may be more widespread in coal measure graphite and natural coke, which is the target of our future research," the expert added.