Fabrication and Characterization of Two-Dimensional High-Entropy Sulfides and Tellurides

Since the discovery of graphene monolayers by mechanical exfoliation in 2004, many other two-dimensional (2D) materials have been synthesized, such as transition metal dichalcogenides (TMDs), hexagonal boron-nitride (<i>h</i>-BN), black phosphorous. Another category of materials, high entropy alloys (HEAs) are constructed by the combination of multiple principal elements at an equimolar or near-equimolar fraction. HEAs offer an extensive combinatorial space facilitating superior functionalities that are generally lacking in conventional alloys composed only of one or two principal elements.<br/>The combination between 2D materials and HEAs results in a new 2D high-entropy materials (2D HEMs). Even though 2D HEMs has significant potential towards catalysis and energy storage, the rationale and criterion for designing 2D HEMs and demonstration of feasibility in synthesizing 2D HEMs are still missing.<br/>In this presentation, we will demonstrate the successfully synthesized five-metal-element sulfide and tellurides. Sulfides have been synthesized through chemical vapor deposition (CVD) method and tellurides have been obtained via the conventional solid-state reaction (SSR) approach. Advanced characterization techniques have been performed to confirm that uniform element distribution and single phase 2D HEM have been achieved. The designed and fabricated 2D HEMs adds an exceptional family member to the fast-growing field of 2D materials.