Synthetic approaches to two-dimensional transition metal dichalcogenide nanosheets

Two-dimensional transition metal dichalcogenides (TMDCs) have become the focus of intense research due to their unique physical and chemical properties. These features arise from the anisotropic effects of the materials as it is thinned towards a monolayer. Several review articles have exhaustively examined the structures and applications of such materials, whereas relatively little critical analysis has been applied to the ever-expanding array of synthetic methods. This review thoroughly documents all synthetic methods to 2D-TMDCs (by both 'top-down' and 'bottom-up' approaches) published up to January 2015, by considering the quality and characteristics of the nanosheets produced. This work has been achieved by directly comparing the crystallinity, dimensions, yields and electronic properties of selected TMDC nanosheets with respect to each method. Finally this review concludes with an examination of the next generation 2D-TMDCs that explores the production of ternary TMDC nanosheets, heterojunctions between two TMDCs, and the production of patterned nanosheet surfaces.