Scalable Reshaping of Diamond Particles via Programmable Nanosculpting.

Diamond particles have many interesting properties and possible applications. However, producing diamond particles with well-defined shapes on a large scale is challenging because diamonds are chemically inert and extremely hard. Here, we show that air oxidation, a routine method for purifying diamonds, can be used to precisely shape diamond particles at scale. By exploiting the distinct reactivities of different crystal facets and defects inside the diamond, layer-by-layer outward-to-inward and inward-to-outward oxidation produced diverse diamond shapes including spheres, twisted surfaces, pyramidal islands, inverted pyramids, nanoflowers, and porous polygons. The nanosculpted diamonds had more and finer features that enabled them to outperform the original raw diamonds in various applications. Using experimental observations and Monte Carlo simulations, we built a shape library that guides the design and fabrication of diamond particles with well-defined features that could be critical for anticounterfeiting, optical, and other practical applications. Our study presents a simple, economical, and scalable way to produce shape-customized diamonds for various potential technologies.