Recovery of ultrasmall nanodiamonds from plastics shock-compressed to pressures around 100 GPa

Nanodiamonds exhibit outstanding properties and are valued for a wide range of scientific and industrial applications. However, the scalable production of ultrasmall ( < 5 nm), high-purity nanodiamonds with narrow size distributions remains challenging. Here, we demonstrate the successful recovery of ultrasmall nanodiamonds from polyethylene terephthalate (PET), which was shock-compressed by high-energy nanosecond laser pulses to initiate exotic chemistry at pressures around 100 GPa and temperatures around 4000 K. Using a vacuum-compatible, water-soluble ionic gel catcher, we extract nanodiamonds with diameters averaging 3 nm and a standard deviation below 1 nm. Demonstrating the successful release and recovery from pressures more extreme than for common detonation synthesis, our results point to a potential path to a relatively clean, scalable and sustainable approach to the production of ultrasmall nanodiamonds.