Laser-scribed ultrasmall nanoparticles with unary and binary phases

Ultrasmall nanoparticles embedded in conductive support have immense potential in catalytic and energyrelated applications, yet developing a fast and proper synthesis method remains a challenge. Herein, we demonstrate that, via simple laser scribing, isostructural metal-organic frameworks can be readily transformed into ultrasmall nanoparticles (5-14 nm) with different elemental compositions embedded in conductive carbon support. We found that the formation kinetics of nanoparticles is controlled by the thermodynamic reducibility of metal ions in the metal-organic framework as well as the cooling rate. This method allowed us to precisely tune the particle size and uniformity as well as the composition. As a potential application of the produced nanoparticles, we evaluated the electrocatalytic behavior of the Ni nanoparticles embedded in carbon support. It exhibited excellent performance and stability for the hydrogen evolution reaction in both acid and alkaline electrolytes.