Synthesis of Some Functional Oxides and Their Composites Using Sol-Gel Method

Abstract

Two main approaches for nanomaterials fabrication are the top-down and the bottom-up methods. The first is limited to mechanical grinding, thermal evaporation, ion sputtering, arc discharge, pulsed laser ablation, and other physical and chemical vapor deposition. These routes are costly, consume higher energy, and require complex technology such as ultrahigh vacuum. The bottom-up methods refer to the production of complex nanostructured materials from atoms and molecules. This approach is relatively simple and low in cost. However, it requires a good knowledge of the optical properties of the particles and their modifications when the particles are integrated with nanostructures. One of the widest bottom-up methods is the sol–gel. It involves a solution or sol (single-phase liquid) that undergoes a sol–gel transition (stable suspension of colloidal particles). In this chapter, we throw light on the history of sol–gel, its advantages, and limitations, operating this method for the production of different types of nanomaterials in the form of powders or thin films. In addition, some applications of the sol–gel-derived nanosized materials will be discussed.