Sol-Gel Methods for the Assembly of Metal and Semiconductor Nanoparticles

The ability to assemble nanoparticles into functional structures is an important challenge that needs to be addressed for the generation of nanoparticle-based devices. Sol-gel method represents a facile yet powerful strategy for the self-assembly of metal oxides, chalcogenides, and metal-semiconductor hybrid nanoparticle systems into three-dimensionally connected porous nanostructures. In contrast to traditional oxides, where gels are formed by hydrolysis and condensation of molecular precursors, gelation in non-oxidic systems (with the exception of carbon), is achieved by condensation of the pre-formed nanoparticles. In this highlight, the application of later strategy for the assembly of chalcogenide semiconductor and noble metal nanoparticles and their intriguing physical properties is reviewed in the context of future application in catalysis, sensing, and separation technologies.