Maneuvering Tellurium Chemistry to Design Metal–Telluride Heterostructures for Diverse Applications

Heterostructures of metal chalcogenides have attracted immense attention due to their enhanced charge transport, synergistic optoelectronic and catalytic properties. While heterostructures of metal–sulfide or metal–selenide nanocrystals have been studied extensively, those of metal–telluride nanocrystals are less explored due to the lower abundance of tellurium. However, tellurium, a group VI element placed at the border between metals and nonmetals in the periodic table, has the ability to adopt multiple oxidation states, from positive to negative, and a strong proclivity toward anisotropic growth. These singularizes it from other chalcogenide semiconductors and also helps the design of nanostructures of tellurium using Te(0) and Te2– as the initial precursors. Hence, understanding Te chemistry for nanostructure formation in solution is an essential research area that needs further exploration. Considering this, herein, the synthesis of metal–telluride heterostructures using various chemical routes has been elaborated. The chemistry of the formation of these materials using the direct-seeded approach, cation and anion exchange, and coupling with noble metals, among other methods, are detailed in this review. Furthermore, different device applications of the Te-based heterostructures are analyzed and their performances are summarized. Additionally, the chemical manipulation of tellurium chemistry to engineer complex nanoheterostructures and their possible applications are also proposed as future prospects.