Chapter 7 - Flame Synthesis of Nanostructured Transition Metal Oxides: Trends, Developments, and Recent Advances

Abstract

This chapter focuses on the application of flames for the synthesis of transition metal oxide (TMO) nanostructures. It contains trends, developments, and recent advances in the flame synthesis of TMOs. TMOs are among the most highly sought-after nanomaterials owing to their unique properties. It has been shown that by the simple conversion of a bulk material into tiny structures a remarkable modification of their properties relative to their bulk can occur. Additionally, the alteration of the elemental composition of the nano- and micron-sized structures (i.e., 1D and 3D) from its bulk material can significantly enhance the material properties, fostering many innovative applications. Historically, flames have been used for the synthesis of TMOs at the industrial scale. These flame processes introduce the source material in the form of aerosol or flame spray pyrolysis. These methods have resulted in synthesis aggregates and powders composed of chain-like spheroidal primary particles. Most recently it has been shown that the manipulation of some parameters (e.g., flame chemistry and temperature, introduction of source material, etc.) can result in the flame synthesis of TMOs with unique morphology and dimensionality. Recent research has led to the flame synthesis of more exotic TMOs, including core–shell and well-mixed TMOs. A brief introduction to the properties and applications of nano-sized TMOs along with a brief description of conventional methods for their synthesis are presented.