The Power of Nanomaterial Approaches in Gas Sensors

The challenge of nanotechnology is to discover new effects on already known materials and to convert exciting new findings into advanced technologies that are useful for industrial applications.
In these years, researchers have achieved the ability to produce quasi-one- dimensional (Q1D) structures in a variety of morphologies such as nanowires, core shell nanowires, nanotubes, nanobelts, hierarchical structures, nanorods, nanorings. In particular, Q1D Metal OXides (MOX) are attracting an increasing interest in gas sensing application: nanosized dimension ensures high specific surface that leads to the enhancement of catalytic activity or surface adsorption. Moreover, single-crystalline structures with well-defined chemical composition and surface terminations are not prone to thermal instabilities suffered from MOX polycrystalline counterpart. All these peculiarities can help to fill the gap between research and industrial application needs, aiming at the development of a reliable, low cost gas sensor.
This chapter presents an up-to-date survey of the research on Q1D metal oxide materials for gas sensing application, addressing the preparation techniques of sensing nano-crystals in connection with their electrical and optical properties. The application as resistive, transistor-based or optical-based gas sensors will be treated.