Scientists Flatten 'Nano-Onions' into Customisable 2D Discs

Onion-like carbon nanomaterials (OLCNs)—tiny spheres of carbon structured like an onion’s layers—have long been limited by their lack of structural variety. Now, researchers have pioneered a method to reshape these zero-dimensional points into something new: customisable, hollow, quasi-two-dimensional discs.

The breakthrough involves using layered double hydroxides as a nano-scale mould. Under specific conditions, this structure acts as a confinement chamber, forcing the carbon precursor to grow into a flattened, disc-like architecture instead of its usual spherical form. This innovative process offers remarkable control over the final product.

Scientists can now fine-tune the nanomaterial’s diameter, height, the size of its hollow core, and even its fluorescence lifetime—a measure of how long it glows after being excited by light. This ability to precisely engineer OLCNs from 0D to quasi-2D structures significantly expands their potential in future technological applications.