Nanoparticle-Based Inorganic Aerogels

The use of preformed nanoparticles as building blocks represents a versatile alternative to molecular routes to fabricate inorganic aerogels. The immense variety of nanoparticles covering a broad range of compositions, morphologies, and crystal structures gives access to aerogels with unprecedented architectures, including multiple nanoparticle combinations, nanoheterostructured (e.g., core-shell) configurations, or materials with anisotropic inner structure. In this book chapter, different approaches to inorganic nanoparticle-based aerogels are presented, divided according to their composition into metal chalcogenides, metals, and metal oxides. The chapter starts with a short introduction to the most important wet-chemical methods for the synthesis of nanoparticles, followed by a discussion of the different strategies to destabilize nanoparticle dispersions to induce gelation. After presenting an overview of nanoparticle-based aerogels, the book chapter concludes with a few examples of selected applications in photocatalysis and energy storage – fields of applications, where nanoparticle-based aerogels, mainly in monolithic form, are particularly advantageous.