General synthesis of high-entropy alloy and ceramic nanoparticles in nanoseconds

High-entropy materials, which include high-entropy alloys and high-entropy ceramics, show promise for their use in many fields, yet a robust synthesis strategy is lacking. Here we present a simple and general approach, laser scanning ablation, to synthesize a library of high-entropy alloy and ceramic nanoparticles. The laser scanning ablation method takes only five nanoseconds per pulse to ablate the corresponding nanoparticle precursors at atmospheric temperature and pressure. The ultrarapid process ensures that dissimilar metallic elements combine regardless of their thermodynamic solubility. As a laser pulse confines energy to the desired microregions, the laser scanning ablation method renders a high-entropy material nanoparticle loading on various substrates, which include thermally sensitive substrates. Applied as electrocatalysts for overall water splitting, the as-prepared high-entropy material nanoparticles can achieve an overpotential of 185 mV @ 10 mA cm–2. This versatile strategy enables the preparation of materials useful for a range of fields, such as biomedicine, catalysis, energy storage and sensors.