Growth Mechanism and Surface Functionalization of Metal Chalcogenides Nanostructures

Following the discovery of carbon fullerenes and nanotubes (NTs), nanostructured materials and their synthesis have attracted tremendous attention due to their superior mechanical properties, their unique electronic behavior, and their high potential in making technologically advanced nanodevices. Among different classes, layered metal chalcogenides nanostructures are of interest for a variety of applications ranging from nanoelectronics or as source materials for energy applications, nanotribology and in heterogeneous catalysis. These nanoparticles are metastable phases. Therefore, equilibrium methods are necessary to prevent the formation of the thermodynamically stable bulk phase. On the other hand, high energies are needed to "knit" together the folded layers. Several physical techniques such as laser ablation and arch discharge are used for the synthesis of these inorganic NTs and fullerene-like particles. Apart from these high-energy techniques other processes such as oxide-to-sulfide conversion, hydrothermal, solvothermal, or wet chemical synthesis were found to be useful for the synthesis of these particles. In order to benefit from the outstanding properties of nanomaterials, their functionalization is essential, as any application in materials and devices is hindered by difficulties in processing and manipulation. Only the attachment of appropriate chemical functionalities on the nanoparticle surface allows a tailoring of their properties for the respective application. Tailoring of the surface chemical bonds might as well lead to an optimized interaction of the nanoparticles with solvent molecules, polymer matrices, or biomolecules. Therefore, the nanoengineering of particle surfaces is a key for the design and tailored construction of innovative nanomaterials. This chapter includes the discussion on growth mechanism of metal chalcogenides synthesized using different methods and various protocols for their surface functionalization to improve the processability in technological applications.