dr. Alexey Ganin: Soft Chemistry Pathways to Synthesis of Inorganic Graphenoids
|Wanneer:||vr 25-04-2014 14:00 - 15:00|
The discovery of new phenomena and the development of specific properties of existing functional materials rely upon our ability to direct reaction pathways toward materials with desired structure and composition. This is especially true for newly emerging class of materials - inorganic graphenoids - which can be viewed as atomically thin but micrometric in lateral size “modules”. Among others, exfoliated layered metal chalcogenides display a wide range of useful electronic properties making them attractive two-dimensional modules for design of materials with tailored properties, for example by intergrowth of semiconducting and magnetic blocks. There has also been a growing interest for using metal chalcogenides in batteries and supercapacitors applications and this requires operating the synthesis at reduced temperatures to enable formation of metal chalcogenide - carbon composites.
This lecture will explore the intercalation reactions into metal chalcogenide hosts using a wide range of reducing agents based on polyaromatic hydrocarbons, look into the activity of the reduction agents and its impact on the chemical composition of the fabricated materials. It will investigate the possible precursors for the liquid phase exfoliation process and implementation of the process for fabrication of colloidally dispersed building blocks. This top-down approach will be discussed from the point of view of using the blocks as modules for generating complex stacking sequences of metal chalcogenides, for example, by layer-by-layer assembly. Finally, the liquid exfoliation process will be compared with solvothermal process, which is a more traditional bottom-up approach for synthesis of metal chalcogenide nanostructured materials, by using specific examples of CoMoS2/Graphene composite materials.