Nanoparticles are usually designed for specific applications and selection of the most convenient capping can be a complex task, but is crucial for successful design. In this volume, the authors discuss the selection of functional cappings to coat nanoparticles in a range of different applications. The opening chapter provides an understanding of basic aspects of surface chemistry at the nanoscale. Each following chapter covers a particular kind of capping, beginning with a basic introduction and describing characteristics such as structure, functionality, solubility, (photo)physics, and toxicity. Special emphasis is placed on how important these specific features are in the preparation of smart nanomaterials. In-depth explanations and examples are then presented, highlighting the latest results and cutting-edge research carried out with the selected capping according to the kind of nanoparticle employed (such as rare-earth doped, semiconducting, and metallic). An additional chapter focusses on computational techniques for modelling nanosurfaces. Photoactive Inorganic Nanoparticles: Surface Composition and its Role in Nanosystem Functionality will be a valuable working resource for graduate students, researchers, and industry R&D professionals working in the field of applied nanomaterials.