An onion-like fullerene. [Photo provided by CUMT]

Researchers at the China University of Mining and Technology (CUMT), which is located in Xuzhou, East China's Jiangsu province, recently discovered an onion-like fullerene in a coalfield in East China's Fujian province.

The object has a diameter of 55 nanometers. Chen Yilin, one of the researchers and an associate professor at the university's School of Resources and Geosciences, said the natural onion-like fullerene, which is called as such because it has multiple concentric layers, is the largest one known in the world by far and contains more than 2 million carbon atoms. Most natural onion-like fullerenes are 20 to 30 nanometers in diameter.

Due to the material's electronic, optical, electromagnetic and tribological properties, it can be used in a wide range of sectors, such as aviation, aerospace, biomedicine, and environment restoration. Onion-like fullerenes can be made in laboratories but are very expensive – they cost about $3 million to $3.35 billion per metric ton.

Researchers at CUMT think onion-like fullerenes are created during the transformation of coal caused by magma intrusions, and that this special material is likely to be more commonly found than people used to think.

A multi-core onion-like fullerene was also found at the Fujian coalfield for the first time.

The findings, said Chen, are of great value scientifically as they will help scientists find more onion-like fullerenes, push the boundaries of China's fundamental science, and promote the green transition of the coal industry.