Dependence of the Properties of 2D Nanocomposites Generated by Covalent Crosslinking of Nanosheets on the Interlayer Separation: A Combined Experimental and Theoretical Study.

Covalently cross-linked heterostructures of 2D materials are a new class of materials which possess electrochemical and photochemical hydrogen evolution properties. It was of considerable interest to investigate the role of interlayer spacing in the nanocomposites involving MoS2 and graphene sheets and its control over electronic structures and catalytic properties. We have investigated this problem with emphasis on the hydrogen evolution properties of these structures by a combined experimental and theoretical study. We have linked MoS2 based nanocomposites with other 2D materials with varying interlayer spacing by changing the linker and studied their hydrogen evolution properties. The hydrogen evolution activity for these composites decreases with increasing linker length, which we can link to a decrease in magnitude of charge transfer across the layers with increasing interlayer spacing. Factors such as the nature of the sheets, interlayer distance as well as the nature of the linker provide pathways to tune the properties of covalently cross-linked 2D material rendering this new class of materials highly interesting.