Ionic liquids represent a new class of solvent which offer many advantages over existing solvents, and importantly, are non-volatile and therefore do not escape into the environment by evaporation. This project explores the use of ionic liquids in various applications including catalysis (important to the chemical industry), in solar cells, and in materials chemistry. Our aim is to design new ionic liquids which have specific properties and functions and therefore can potentially enhance the performance of certain applications. To achieve these aims we study fundamental properties of ionic liquids and from these basic studies we apply what we have learnt to design of new ionic liquids and explore their applications. In particular, we are studying their role in facilitating the formation of nanoparticles and their catalytic properties.