Engineering Porosity into Single-Crystal Colloidal Nanosheets Using Epitaxial Nucleation and Chalcogenide Anion Exchange Reactions: The Conversion of SnSe to SnTe

Single-crystal colloidal SnSe nanosheets react with a trioctylphosphine–tellurium complex to transform into porous single-crystal SnTe nanosheets with oriented nanocube protrusions. This chemical transformation reaction, which provides chemical and crystallographic guidelines for designing secondary nanostructural features into single crystal colloidal nanosheets and also results in two-dimensional nanosheets of a three-dimensionally bonded material, proceeds via a diffusion-mediated anion exchange pathway. Intermediate nanosheets reveal that SnTe nucleates with crystallographic alignment on the surface of the SnSe nanosheet, which ultimately is consumed to produce the porous SnTe nanosheet product. The anion exchange reaction is general, successfully converting a library of metal selenides and sulfides to the corresponding tellurides.