Structures and properties of ordered nanostructured oxides and composite materials

MARTINEZ RICCI, MARIA LUZ; SARA ALDABE BILMES

The Sol-Gel Handbook: Synthesis, Characterization, and Applications

Wiley-VCH

Lugar: Weinheim; Año: 2015; p. 1031 - 1054

Ordered nanostructured oxides are materials in which nano-objects are arranged in an array with a defined periodicity. Among them, ordered mesoporous oxides (OMPO), such as TiO2, SiO2 and ZrO2 are considered for a wide range of technological applications due to their low-cost reproducible synthesis and chemical stability. These OMPO films exhibit calibrated size pores (2-50 nm) and a high surface area that can be tuned using sol-gel synthetic pathways combined with self-assembly of amphiphillic molecules. Functional optical properties of OMPO films can be tailored reacting to changes in the environment, such as relative humidity or vapors in a selective way. Multilayers of OMPO with different composition grown by sol-gel behave as photonic crystals where the photonic band gap can be fitted by tuning the pore?s size and shape. In addition to these composite structures, those derived from embedding metal or semiconductor nanoparticles within OMPO films produce new plasmonic and luminescent materials enhancing the possibility of new applications. In this chapter we present some basic concepts on the optical properties of OMPO in relation with sol-gel synthesis process, and we discuss the potential applications for the design of optical sensors.