Tetrahedral Transition Metal Chalcogenides as Functional Inorganic Materials
Seminar | August 25 | 4-5 p.m. | 120 Latimer Hall
Transition metal dichalcogenides (TMDs) have resurfaced as functional inorganic materials for their diverse applications including transistor-type devices, sensors, and hydrogen evolution catalysis. We present a more recent category of layered materials we term tetrahedral transition metal chalcogenides (TTMCs) that display different functional behavior from TMDs. These layered TTMCs are built of square metal lattices with electron rich transition metals such as Fe(II) and Co(II) in tetrahedral coordination. Due to the weak van der Waals interactions that hold the chalcogenide layers together, intercalation chemistry in aqueous solutions can be utilized to prepare new phases with interesting magnetic and electronic properties including ferromagnetism and superconductivity. Our groups strategy has been to incorporate guest species into the TTMC hosts to tune the physical properties. We construct a simple bonding model to interpret the electronic structure of the square metal lattice in TTMCs, and use it to predict the properties of future phases. Furthermore, we demonstrate that these layered metal chalcogenides could be made into novel two-dimensional (2D) materials either as single layers or as heterostructures with other 2D motifs.