Three Complementary Strategies for Synthesizing Colloidal Nanoparticles of High Entropy Transition Metal Ditellurides

Nanoparticles of transition metal dichalcogenides, including tellurides, are widely used for their dimension- and size-dependent electronic, magnetic, optical, and catalytic properties. Additional tunability can emerge from high-entropy compositions, where five or more metals randomly mix on the crystalline lattice sites. Colloidal routes for synthesizing transition metal ditelluride nanoparticles can be challenging, as can achieving high-entropy mixing in colloidal nanoparticles. Here, we present three complementary strategies for synthesizing colloidal nanoparticles of high-entropy transition metal ditellurides that adopt a layered MTe₂ structure. First, we react high-entropy NiPdPtRhIr alloy nanoparticles with diphenyl ditelluride, which maintains the high-entropy mixing upon transformation to (NiPdPtRhIr)Te₂. However, this approach is limited in the compositional scope due to crystal structure considerations. To circumvent this limitation and to produce the high-entropy tellurides (SnPdPtRhIr)Te₂ and (SnNiPtRhIr)Te₂ in addition to (NiPdPtRhIr)Te₂, the second strategy involves direct colloidal synthesis without first forming high-entropy alloy intermediates. Third, preformed Te particles can also transform into MTe₂ high-entropy tellurides by diffusing metal reagents into them. These three strategies, which are complementary in their capabilities and limitations, provide insights for targeting the synthesis of high-entropy transition metal ditelluride nanoparticles.