TiO₂, ZnO and Fe_2O₃ Thin Film Nanomaterials: Preparation to Applications

Nanomaterials have gained a lot of attention of scientists and researchers during the last two decades due to their small size (nano-scale) and large surface area. Amongst these nanomaterials, metal oxide thin film nanoparticles are gaining much more interest due to their exceptional chemical, electronic, catalytic, electrical and optical properties. These properties can be improved to develop essential functionalities and compositions that make them fit for various applications such as catalysts, solar cells, sensors, optoelectronic materials, and green energy storage applications. Thin film metal oxide nanoparticles can be synthesized by different physical or chemical methods like physical vapour deposition, chemical vapour deposition, atomic layer deposition, sol-gel synthesis and hydrothermal synthesis. The usual characterization techniques for metal oxide nanoparticles are SEM, HRTEM, EDX analysis, XRD, FTIR, XPS, and TGA–DTA etc. Many metal oxides like TiO2 and ZnO have excellent properties like photo-induced phenomenon under UV radiation and superconducting properties. Thus, their thin film nanoparticles can work more efficiently than the bulk one. This chapter explains about the synthesis of some metal oxides like TiO2, ZnO, and Fe2O3 through various physical and chemical methods, and the characterization and application of metal oxide thin film nanoparticles for solar cells, fuel cells, photovoltaic cells, optoelectronic application, and green energy storage application.