Deciphering gas phase synthesis of sulfide nanoparticles

Abstract

With the ever-increasing need for impressively engineered materials, research has taken a shine to nanosized materials. This has been predominantly because matter on a nanoscale exhibits behaviours unusual to their bulk counterparts. Taking advantage of these properties on the nanoscale has been applied in many areas of research. This thesis is focused on a particular group of nanomaterials – metal sulfides and their production through combustion synthesis. Metal sulfide nanoparticles are attractive materials for a wide range of applications. The synthesis of metal sulfide nanoparticles has predominantly been through liquid-phase synthesis. Although it can be highly versatile, challenges of scaling up production and the requirement for post-processing exist. Combustion of liquid precursors using a flame set-up is an established and highly scalable route of synthesis for metal oxide nanoparticles. As combustion requires oxygen, the synthesis of metal sulfides through this route is a challenge. This thesis delves into sources of metal and sulfur sources that are ideal for producing metal sulfide nanoparticles through combustion, tailored precursor-solvent solutions and mechanisms of breakdown and formation. Here, tetrahydrothiophene (THT) is used as an effective source of sulfur to produce metal sulfide nanoparticles such as those of copper and iron. In addition, specific components formed on the high-temperature breakdown of the sulfur source are investigated. Precursor-solvent solutions are poked and prodded using evaporation and distillation, the results of which were unexpected nor have been reported in prior studies.