Synthesis and reactivity of two-dimensional materials: layered transition metal dichalcogenides and templated bismuth tungstate

Nanosheets, highly ordered materials with thicknesses of a monolayer or few-layers and lateral dimensions in the micrometer range, can be made by either bottom up or top down approaches. In the bottom up approach, nanosheets are formed directly. Chapters II and III outline a bottom down approach to create the metal oxide bismuth tungstate (Bi2WO6) using reactive nanosheet precursors that provide a templating effect to produce Bi2WO6 nanosheets with lateral dimensions in the micrometer range. Alternatively, in the top down approach, large pristine crystals of a bulk material are reduced to nanosheets by delamination or exfoliation. This is the method of choice discussed in Chapter IV for transition metal dichalcogenides, whose van der Waals structure allows for easy separation into mono- or few-layer nanosheets. Chapter IV focuses on a top down approach for forming tantalum diselenide nanosheets, along with the materials structure, oxidation effects, characterization, and novel applications.