Nanomaterials are particularly nanocomposites are critical components in a large number of energy conversion and storage systems. Nanomaterials maximize the interaction with the media, which is a fundamental parameter in the fields of catalysis and electrocatalysis, among other. Nanomaterials have associated lower thermal conductivities and improved mechanical properties, which are advantageous properties in the field of thermoelectricity. Additionally, nanomaterials may be able to sustain high volume changes more effectively, which is a key advantage in ion intercalation batteries. While numerous strategies to produce nanocomposites have been developed, most of them lack of a sufficient control over material parameters to fully optimize their performance, or are unpractical for real applications that require low cost and high throughput production processes. In this context, bottom up approaches that make use of colloidal nanocrystals as building blocks to engineer nanocomposites are emerging as a suitable alternative. Colloidal synthesis routes allow an extremely precise control over material parameters without particularly high capital or operating costs (ambient pressures, low temperatures) and with high-throughput production and material yields. Stimulated by its simplicity and huge potential, countless groups all over the world have developed colloidal synthesis routes to produce nanocrystals of a plethora of materials, making available an extensive library of synthetic strategies and routes to produce nanocrystals with almost any composition, size and facets. However, for such control over material parameters to truly impact real applications, colloidal nanocrystals need to be properly organized or arranged into functional unsupported superstructures, high resolution patterns, thin films, porous nanomaterials or highly dense nanocomposites, depending on the application. Such nanocrystal arrangement need to ensure proper optical characteristics, charge transport properties, interaction with the media, etc, when compared with competing technologies in each field. In this talk, I will present our work on the arrangement of colloidal nanocrystals into macroscopic nanomaterials and nanocomposites and their use for a few exemplifying applications, underlying the real advantages and remaining challenges.
