Surface sites of nanomaterials: investigation of local structures by in-situ IR spectroscopy

Since the last part of the twentieth century, research in the field of nanotechnology and nanomaterials has certainly become a key pillar of modern science due to the potential heavy impact on technological, industrial and medical fields. Although the term “nanotechnology” has been used for the first time by Japanese scientist Norio Taniguchi in 1974, the basics of the subject were first expressed in 1959 by the physicist Richard Feynman, Nobel Prize in Physics in 1965, during the famous speech “There's Plenty of Room at the Bottom” at an American Physical Society meeting at the California Institute of Technology. In his talk Feynman, many years before the invention of the scanning tunneling microscope allowed even to see a material at the atomic level, perfectly described the importance of studying and manipulating materials in the nanoscale because “…we have a lot of new things that would happen that represent completely new opportunities for design. Atoms on a small scale behave like nothing on a large scale, for they satisfy the laws of quantum mechanics. So, as we go down and fiddle around with the atoms down there, we are working with different law…we have new kinds of forces and new kinds of possibilities, new kinds of effects”. In fact, physical and chemical properties of materials (such as optical and magnetic properties, electrical conductivity, surface energy and reactivity) significantly change passing form the bulk form to particles in the 1-100 nm size scale, where their behavior is ruled by the so-called quantum effects. Moreover, in the nanoscale, most of these properties are size dependent, opening a wide spectrum of possibilities in terms of manipulation in order to obtain nanomaterials with precise and peculiar features. Depending on their composition, nanomaterials can be employed in a wide range of applications, such as photo-catalysis and catalysis (e.g. TiO2 and Pd based nanoparticles respectively), energy conversion and storage devices (e.g. TiO2 and ZnO based solar cells), biological and chemical sensing (e.g. fluorescent silica nanoparticles, Au, Fe2O3 based magnetic nanoparticles), drug delivery (silica and polymer based noncomposites), biocompatible materials for bones regeneration (e.g. hydroxyapatite) and substitution (e,g, titanium based materials) and SERS and SEIRA (coinage metal nanostructures).