A heating treatment method to make crystalline nanoparticles with a high surface-area-to-volume ratio for catalytic applications.

Catalysis, the acceleration of a chemical reaction by adding a catalyst material, plays a major role in many emerging technologies, with applications from petroleum refinement to carbon dioxide reduction. One powerful class of catalysts is transition metal dichalcogenides (TMDs). TMD catalysts are currently limited due to difficulties creating a high surface area to volume ratio and an ordered crystalline structure in a nanoscale package.

The authors developed a heating method to create crystalline nanoparticles with a high surface-area-to-volume ratio from MoS2, a 
type of TMD. This approach is fast, takes only a few seconds, and produces nanoscale islands of crystalline MoS2.

Many TMD studies have investigated the effects of temperature on phase stability and structure. The authors expanded this work by examining the effects of heating rates. They found that heating pristine MoS2 from 500°C to 700°C at a fast rate of 25°C per second creates islands of crystalline MoS2. These islands appear in the 2-H and 3-R phases and are almost perfectly crystalline. The authors confirmed these results using scanning transmission electron microscopy, energy dispersive x-ray spectroscopy, and in-situ transmission electron microscopy measurements.

• Heating time of just 8 seconds
• Islands of crystalline 2-H and 3-R phases, providing excellent ordering and uniformity
• Structures on the order of 10 nm, enabling nanoscale catalyst technologies